GOVDOC t1 BOSTON PUBLIC LIBRARY GOVSRNMENT DOCUMENTS UEPARTWEKT t_RECEIVED FEB 1 6 2000 I The Pesticides Monitoring Journal is published quarterly under the auspices of the FEDERAL WORKING GROUP ON PEST MANAGEMENT (responsible to the Council on Environmental Quality) and its MONITORING PANEL as a source of information on pesticide levels relative to man and his environment. The WORKING GROUP is comprised of representatives of the U. S. Departments of Agricul- ture; Commerce; Defense; the Interior; Health, Education, and Welfare; State; Tranrportation; and Labor; and the Environmental Protection Agency. The pesticide MONITORING PANEL consists of representatives of the Agricultural Research Service, Animal and Plant Health Inspection Service. Extension Service. Forest Service, Depart- ment of Defense, Fish and Wildlife Service. Geological Survey. Food and Drug Administration. Environmental Protection Agency. National Marine Fisheries Service. National Science Founda- tion, and Tennessee Valley Authority. Publication of the Pesticides Monilorinf; Journal is carried out by the Division of Technical Services of the Environmental Protection Agency. Pesticide monitoring activities of the Federal Government, particularly in those agencies repre- sented on the pesticide MONITORING PANEL which participate in operation of the national pesticides monitoring network, are expected to be the principal sources of data and interpretive articles. However, pertinent data in summarized form, together with interpretive discussions, are invited from both Federal and non-Federal sources, including those associated with State and community monitoring programs, universities, hospitals, and nongovernmental research institu- tions, both domestic and foreign. Results of studies in which monitoring data play a major or minor role or serve as support for research investigation also are welcome; however, the Journal is not intended as a primary medium for the publication of basic research. Manuscripts received for publication are reviewed by an Editorial .Advisory Board established by the MONITORING PANEL. Authors are given the benefit of review comments prior to publication. Editorial Advisory Board members are: John R. Wessel, Food and Drug Administration, Chairman Paul F. Sand, Animal and Plant Health Inspection Service. I'ice Chainnan Anne R. Yobs, Environmental Protection Agency William F. Durham, Environmental Protection Agency Thomas W. Duke, Environmental Protection Agency William H. Stickel, Fish and Wildlife Service Milton S. Schechter, Agricultural Research Service Herman R. Feltz, Geological Survey Mention of trade names or commercial sources in the Pesticides Monitoring Journal is for identification only and does not represent endorsement by any Federal agency. Address correspondence to: Mrs. Sylvia P. O'Rea: Editorial Manager PESTICIDES MONITORING JOURNAL U.S. Environmental Protection Agency 4770 Buford Highway, Bldg. 29 Chamblee, Georgia 30341 ^4tAH.^,7-^ CONTENTS Volume 7 June 1973 Number 1 Page PESTICIDES IN PEOPLE Organochlorine pesticide residues and polychlorinated biphenyls in hitman milk, Colorado — 1971-72 E. P. Savage, J. D. Tessari, J. W. Malberg. H. W. Wheeler, and J. R. Bagby RESIDUES IN FISH, WILDLIFE. AND ESTUARIES Accumulation and movement of mirex in selected estuaries of South Carolina. 1969-71 P. W. Borthwick, T. W. Duke, A. J. Wilson, Jr.. J. I. Lowe, J. M. Patrick, Jr., and J. C. Oberheu Eggshell thinning, Chlorinated hydrocarbons, and mercury in inland aquatic bird eggs, 1969 and 1970 27 Raymond A. Faber and Joseph J. Hickey International cooperative study of organochlorine and mercury residues in wildlife, 1969-71 37 A. V. Holden Pesticide residues in natural fish populations of the Smoky Hill River of western Kansas — 1967-69 ,53 Harold E. Klaassen and Ahmed M. Kadoum Organochlorine pesticides and polychlnrinaied biphenyls in black duck eggs from the United States and Canada — 1971 62 Jerry R. Longcore and Bernard M. Mulhern \tcrcury. lead, cadinnun. and arsenic residues in starlings — 1971 67 William E. Martin and Paul R. Nickerson PESTICIDES IN WATER Pesticides in selected western streams — 196S-7I 73 Jean A. Schuize, Douglas B. Manigold, and Freeman L. Andrews APPENDIX Cluinical nanus of citinponiuls discussed in this issue 85 PESTICIDES IN PEOPLE Organochlorine Pesticide Residues and Polychlorinated Biphenyls in Human Milk, Colorado — 1971-72 ' E. p. Savage, J. D. Tessari, J. W, Malberg, H. W. Wheeler, and J. R. Bagby ABSTRACT Organoclilorine pesticide residues and PCB's were deter- mined in 40 liiiman milk samples collected from women in rural Colorado durinf; 1971-72. The highest levels found were of p,p'-DDE which ranged from 19 to 386 ppb: p.p'- DDT ranged from 7 to 109 ppb. ji-BHC, o. p'-DDT, dicl- drin, heptachlor epo.xide, and p,p'-DDD ranged from a trace to 38, 13, II, 5, and 5 ppb, respectively, PCB's ranged from 40 to 100 ppb. P,p'-DDE and p.p'-DDT were found in all milk samples, ft-BHC in 87.5%, and PCB's in 20%. Introduction Laug et al. (5) reported DDT in 30 of 32 human milk samples collected in the Washington. D.C.. area in 1951. Since that time, a number of investigators in the United States and other areas of the world have reported or- ganochlorine compounds in individual and pooled human milk samples. Recent interest in the polychlori- nated biphenyls (PCB's) has also resulted in several in- vestigators reporting on PCB's in human adipose tissues, plasma, and human milk. Dyment ct al. {2) were unable to find PCB's in human milk collected from participants living in Texas and New Guinea. Finklea et al. (3), in a study of 723 plasma samples collected from volunteers living in Charleston County, S. C, found p,/-DDT and DDE almost universal, DDD in 84%, dieldrin in 63%, and PCB's in 43% of the study participant.s. Newton and Greene (7) analyzed f^7 rural and urban human milk samples collected in Australia for organo- chlorine pesticides. All samples contained DDT and DDE. 12 contained DDD. and 29 contained dieldrin; they did not report on PCB's. 'From the Institute of Rural Environmental Health, Department of Microbiology, College of Veterinary Medicine and Biomedical Sciences, Colorado Stale University, Fort Collins. Colo. 80521 The current study reports levels of the organochlorine pesticides /3-BHC. p,p'-DDE, o, p'-DDT. p,p'-DDT, p.p'-DDD. dieldrin. heptachlor epoxide, and the indus- trial pollutant PCB's in 40 human milk samples collected from women in rural Colorado during 1971-72. Sampling and Analyses Participants were asked to manually express milk samples into glass tubes equipped with plastic screw caps and teflon liners. The filled tubes were kept frozen until time of extraction. Analytical standards for the chlorinated pesticides were obtained from the pesticide repository of the U.S. En- vironmental Protection Agency Laboratory. Perrine, Fla. The Aroclor analytical standards were obtained from the Monsanto Chemical Co.. St. Louis. Mo. Solvents were redistilled in glass prior to use. The evalua- tion, storage, activation, and use of the Florisil followed the recommended procedures described in the "Manual of Analytical Methods" (,S). The extraction procedure used was a modification of those described by Guiffrida et al. (4) and Curley and Kimbrough ( / 1. The procedure consisted of 3 parts; (1) isolating the fat from the milk. (2) extracting the Aro- clors and pesticides from the fat. and (3) cleaning up the extract. Whole milk (4.5 g to 24.3 g) was weighed into clean glass centrifuge bottles. Glass wool was added to adhere to the coarse precipitate of the milk solids. After addi- tion of 100 ml of acetone, the sample was shaken manu- ally for I minute and centrifuged for 2 minutes. The acetone layer was then transferred to a 1 -liter separatory Vol. 7, No. I, June 1973 ] funnel. The extraction procedure was repeated three more times with equal volumes of 25 ml of acetone each time. All four acetone e.xtractions were combined m the 1-liter separatop,' funnel Twenty-five milliliters of n-hexane was then added to the coarse precipitate of milk solids, shaken, centrifuged, decanted, and combined with the acetone extracts in the l-liter separatory funnel. This procedure was repeated, and then a volume of 125 ml of 2^i sodium sulfate solution and 50 ml n-hexane was added to the acetone and hexane extracts. The separatorv funnel was shaken manually for 1 minute and the lower aqueous layer was discarded. The 2n sodium sulfate washing was again repeated, the lower aqueous layer discarded, and the n-hexane layer poured into a 500-ml concentrator flask. The sample extract was taken through the Florisil pro- cedure as described in the "Manual of Analytical Methods" (8). Primary identification and quantification of the pesti- cides was accomplished on a MicroTck 220 Gas Chro- matograph equipped with a Ni''-' electron capture de- tector and Coulson conductivity detector. Two columns having different resolution characteristics were utilized on all samples. Instrument parameters were as follows: Columns: (A) Borosilicatc glass. b'xW. racked with I.S'Jr OV-17 and 1.95''r QF-1 on Gas Chrom Q 100- 120 mesh Applied Science (B) Borosilicatc glass. 6'x'i". packed with 4'7 SE-30 and 6^ OV-210 on Gas Chrom Q 100- 120 mesh Applied Science (CI Borosilicatc glass. 6' x Vi". packed with }'~f OV-1 — column obtained from Tracor Detectors; (A) Electron capture, having 14.5 mc Ni"= lonizinj; source (B) Coulson conductivity operated in the chloride mode Temperatures: (A) Electron capture Injector 245° C Column 200° C Detector 300° C (B) Coulson conductivit) Injector 245° C Column 200° C Furnace 820° C Block 230° C Carrier gas: High purified nitrogen Flow rates: 60 cc/min for Column A 100 cc/min for Column B Approx. 60 cc/min for Column C Primary quantification of the Aroclors was accomplished by thin layer chromatography (TLC). TLC provides a sound approach for the semi-quantitation of the stated PCB's because the various compounds of the series have similar Rf values and therefore produce a single spot. Six percent ethyl ether/ n-hexane eluate, in concentrate form, is treated with K.OH to effect dehydrochlorination of DDT and DDD to their olefins, thus eliminating the problem of separating these pesticides from the PCBs'. Oxidative treatment is then applied to convert any in- terfering DDE to p.p'-dichlorobenzophenone which has an Rf value different from the PCB's. The PCB's are then determined by thin layer chromatography. The procedure used is a modification of the one described in the "Manual of Analytical Methods" (8) which is based on the method used by Mullhern et al. (6). Gas chromatographic sensitivity limits for p.p'-DDT' and Aroclor 1254® were 20 and 500 picograms, respec- tively. TLC sensitivity limits for the Aroclors were based upon visual comparison of sample spot intensity to the intensities of Aroclor standards at 25. 50. 100, and 40C ng'//l. Recovery rates were established by spiking separate milk samples with known amounts of standards as follows: Arocolor 1254® at 0.5 ppm and Arocloi 1260® at 1.25 ppm; /3-BHC, p.p'-DDE. o.p'-DDT />./''-DDD. and dieldrin at 1 pph; p.p'-DDT, a-BHC, al drin, lindane, heptachlor. and heptachlor epoxide at ^^ ppb. These samples were then analyzed utilizing thi- described procedures. Recoveries from the spiked pestii cide samples were based on unspiked control samples' The pesticide recoveries ranged from 85.2 to 118% Recoveries for the Aroclor samples based on five majoi peaks ranged from 75 to S3^; . For further verification- the PCB samples were spotted on thin layer plates ani compared with gas chromatographic data. The TL( recoveries ranged from 75 to 90"^ . Residues were nc corrected for percent recover> . All samples were placed on two different columns fc electron capture detection and then concentrated to 1. ml or below for analyses on the Coulson detector. Results The percent of human milk samples with residues ( organochlorine pesticides and PCB's are presented Table I. P.p'-DDE and p.p'-DDT were found in all 4 milk samples. /3-BHC was found in 87.5% and PCB in 20% of the samples. TABLH 1. — Fcrcciu of total milk .■samples witli organochlorine pesticide residues and PCB's. based on 40 samples. Colorado — 1971-72 Compound Percent Posit Samples p.p'-DDE 100.00 P.p-DDT loo.on /3-BHC 87.5 o.p-DDT 72.5 P.P-DDD 35.0 Dieldrin 45.0 Heptachlor epoxide 25.0 PCBs 20.0 Pesticides Monitoring Journ . The levels of selected organochlorine pesticides and 'CB"s in each of the 40 milk samples are listed in Table ;. The highest levels found were of p.p'-DDE which anged from 19 to 386 pph and p.p'-DDT. from 7 to 09 ppb. /3-BHC. o,/-DDT, dieldrin, heptachlor cp- >xide, and p.p'-DDD ranged from a trace to 38, 13, 11, , and 5 ppb, respectively. PCB's ranged from 40 to 100 )pb. v'alues for total organochlorine pesticides and PCB's in ;ach sample are given in Table 3 with selected cpi- iemiological data for each donor; age, occupation, birth- )lace, number of years lived in Colorado, and whether he participant had ever lived in a city of 50,000 popula- ion or greater. The total organochlorine levels ranged rom a high of 521 to a low of 27 ppb. The age of par- icipants ranged from 19 to 33 years. samples and in 45% of the samples in our study. Dyment et al. (2) did not find PCB's in human milk collected from residents of New Guinea and Te.xas, but Finklea et al. (3) in a study of plasma collected from volunteers liv- ing in Charleston County, S. C, found PCB's in 43% of the study participants. In the current study, we found PCB's in 20% of the samples. Results of this study and other studies indicate that organochlorines are widespread in human milk. Al- though p.p'-DDE and p.p'-DDT are found almost uni- versally, p.p'-DDD. dieldrin, heptachlor epoxide, and PCB's are not as widelv distributed. See Appendix for chemical names of compounds discussed in this paper. Discussion \\\ samples contained p.p'-DDE and p.p'-DDl : 3-BHC was found in 87.5%, o.p'-DDT in 72.5%, iieldrin in 45%, and PCB's in 20% of the samples. Milk from one study participant (No. 20) contained quantifiable levels of all compounds except heptachlor poxide. Heptachlor epoxide and PCB's were never "ound in the same sample in the stud>. and p.p'-DDD ind PCB's were found in the same sample on only one jccasion. The total organochlorines per sample ranged from 27 to 521 ppb. The sample with the lowest level of organochlorines contained p.p'-DDE and p.p'-DDT. The sample with the highest level contained ^-BHC. p.p'- DDE. p.p'-DDT. dieldrin, and a trace of o.^'-DDT. p.p -DDD, and heptachlor epoxide. The highest level of total organochlorines occurred in the sample from a 24-year-old housewife who had spent all but 1 year of her life in Colorado. Only nine women had not lived in a city of 50,000 population or greater. Two of these nine were positive for PCB's. The fact that ^.;>'-DDE and p.p'-DDT were found in all samples was not surprising as Laug ei al. (5) found DDT in 30 of 32 milk samples collected in the Washington, D. C, area in 1951. Newton and Greene (7) found DDl and DDE in all of 67 human milk samples collected in Australia. Dieldrin was recovered in approximately 43 '"P of the Australian LITERATURE CITED (1) Curley, A., and R. Kimbrough. 1969. Chlorinated hydro- carbon insecticides in plasma and milk of pregnant and lactating women. Arch. Environ. Health 18:156-164. (2) Dyment, P. G.. L. M. Hebeitson. E. D. Gomes. J. S. Wiseman, and R. W. Hornabiook. 1971. Absence of polychlorinated biphenyls in human milk and serum from Texas and human milk from New Guinea. Bull. Environ. Contam. Toxicol. 6(6):532-534. (3) Finklea, J., L. E. Priester, J. P. Cieason. T. Hauser, T. Hinners. and D. I. Hanunci: 1972. Polychlorinated biphenyl residues in human plasma expose a major urban pollution problem. Am. .1. Public Health 62(5):645-651. (4) Guiffrida. L.. D. C. Boslwick. and N. /'. Ives. 1966. Rapid cleanup techniques for chlorinated pesticide resi- dues in milk, fats, and oils. J. Assoc. Off. Anal. Chem. 49:634-638. (5) Laug. E. P.. F. M. Knnze. and C. S. Prickell. 1951. Oc- currence of DDT in human fat and milk. Am, Med. Assoc. Arch. Ind. Hyg. 3(3):245-246. t6l Miilhern R. M.. E. Cromarlie. W. L. Reichel. and A. A. Relisle. 1971. Semiquantitative determination of poly- chlorinated biphenyls in tissue samples by thin layer chromatography. J. Assoc. Off. Anal. Chem. .'54(3):548- 550. (7) Newlon. K. G.. and N. C. Greene. 1972. Organochlorine pesticide residue levels in human milk — Victoria, Aus- tralia—1970. Pestic. Monit. J. 6(l):4-8. (8) Thompson, J. F., ed. 1971 . Analysis of pesticide residues in human and environmental samples. (Manual of An- alytical Methods). Prepared for the Community Studies Projects by the Perrine Primate Research Laboratories. U. S. Environmental Protection Agency. Perrine, Fla. Vol. 7, No. 1, June 1973 TABLE 2.- — Residues of selected organochlorine pesticides and PCB's in 40 human milk samples, Colorado — 1971-72 ^-BHC RESIDUES IN PPB (fat basis) p,p-DDE o.p'-DDT p,p-DDT P,p'-DDD DlELDRlN Heptachlor EPOXIDE \i 11 s ft 0 I r I 7 in T-3S 29 98 19 12.1 36 W 52 82 \W 72 79 A I 24 37 57 46 79 17 49 166 135 68 104 186 90 59 30 S3 51 15S 75 42 192 84 1S6 98 41 58 124 262 19-386 8 6 7 12 4 3 6 4 10 4 10 16 25 8 20 21 12 22 21 32 13 14 15 8 II 13 13 15 27 24 10 26 109 12 13 14 14 16 31 13 16 42 20 39 24 10 11 22 43 T T T T T T 3 T 1 T T 1 T 9 4 10 4 T-11 5 2 T T 4 T T T-5 NOTE: — = not Jclecled; T = trace (present at concentrations below the sensiDvily level, confirmed qualitatively but not quantifiable). Pesticides Monitoring Journai TABLE 3. — Total organochlorinc and PCB' t in milk samples, ran ked from highest to lowest, in selected epidemiological data for sample donors, Colorado — 1971-72 Rank OF Samples Donor Number Age (Years) Occupation Birthplace Number of Years Lived IN Colorado Lived in City WITH Population OF 50,000 Total Organochlo- rines and pcb's (PPB) 1 24 24 Housewife Colorado 23 Yes 521 2 40 29 Housewife Florida 8 Yes 342 3 20 25 Housewife Colorado 25 Yes 322 4 33 23 Housewife Japan 1 Yes 322 5 35 19 Housewife North Dakota 7 mos. No 282 6 9 28 Nurse New York 2.5 Yes 197 7 30 27 Housewife Colorado 2 Yes 197 8 21 27 Housewife Minnesota 1 Yes 190 9 36 25 Secretary- Ohio 2 Yes 182 10 39 25 Medical technician Hawaii 4 Yes 153 11 4 unknown 152 12 23 unknown 145 13 31 26 Housewife Michigan 1-) No 134 14 29 22 Housewife Germany Yes 127 15 2 25 Housewife Colorado 2s No 126 16 8 22 Housewife Nebraska 3.5 Yes 115 n 25 unknown 115 18 34 32 Secretary Kentucky 2.5 Yes 115 It 32 20 Housewife Colorado 20 No 115 20 II 24 Housewife Louisiana 8 mos- Yes 110 21 17 28 Housewife California 2.5 Yes 105 22 28 26 Nurse Illinois 4 Yes 101 23 10 33 Housewife Colorado 31 Yes 97 24 22 23 Housewife Missouri 2.5 No 96 25 37 20 Housewife Colorado 19 Yes 95 26 7 28 Student Indiana 7 mos Yes 83 27 38 23 Housewife Colorado 23 No 75 28 26 24 Housewife Colorado IS Yes 72 29 15 20 Beautician Wyominp 19 No 70 30 1 30 Editor Illinois 9 Yes 68 31 19 19 Housewife South Dakota 12 Yes 65 32 5 22 Elementary teacher Colorado 10 Yes 63 33 12 23 Housewife Indiana 1 Yes 63 34 16 28 Housewife Iowa 9 mos. Yes 61 35 18 23 Housewife Pennsylvania in Yes 53 36 6 29 Teacher Kansas 1.5 Yes 53 37 14 30 Housewife California 3 No 53 38 27 21 Beautician Wyoming 7 mos. No 52 39 13 29 Housewife New York 1 Yes 43 40 3 29 Professor Missouri 6 Yes 27 Vol. 7, No. 1, June 1973 RESIDUES IN FISH, WILDLIFE, AND ESTUARIES Accumulation and Movement of Mirex in Selected Estuaries of South Carolina, 1969-71 ' p. W, Borthwick=, T. W. Duke', A. J. Wilson, Jr.=, J. I. Lowe=, J. M. Patrick, Jr.% and J. C. Oberheu' ABSTRACT In conjunction willi a /ire ant eradication program during whicli mirex was aerially applied to coastal areas near Charleston. S. C. field studies were conducted to monitor the movement and accumulation of mirex in the estuarine system. Collections of background and periodic posllreatnient samples of water, bottom sediments, shrimp, crabs, fish, ami estuary-depeiulent birds and mammals were analyzed for mirex tising electron-capture gas chromatography. The data revealed that III mirex was translocated from treated lands and high marsh to estuarine biota — all animal classes sampled contained mirex: and (2) biological concen- tration of mirex occurred — especially in predators such as racoons and birds. Mirex residue ranges for respective .sample categories were: water KlO.OI ppb): sediment (0-0.07 ppm): crabs (0-0.60 ppm): fishes (0-0.82 ppm): shrimps (0-1.3 ppin): mammals (0-4.4 ppm): and birds (0-17.0 ppm). No mass mortalities were observed during the study. Introduction Mirex, a chlorinated hydrocarbon, is the Insecticide component of a bait used in the Southeastern United States to control the imported fire ant (Solenop.sis saevis- siina richteri Forel). This bait was developed after various pesticides and pesticide-bait formulations applied to control the ants proved to he toxic to nontarget or- 1 Contribution No. 156 from the Gulf Breeze Environmental Research Laboratroy, U.S. Environmental Protection Agency, Gulf Breeze. Fla. 32561, an Associate Laboratory of the National Environmental Research Center, Corvallis, Oreg. = Gulf Breeze Environmental Research Laboratory, U.S. Environmental Protection Agency, Gulf Breeze, Fla. 32561. "Bureau of Sport Fisheries and Wildlife, U.S. Department of the In terior, Atlanta, Ga. 30323. ganisms. Large-scale applications of dieldrin and hep- tachlor were especially destructive to fish and wildlife (2). Mirex was developed specifically to control fire ants and, until recently, was not considered to be toxic to nontarget organisms. Independent experiments conducted under controlled I conditions in the laboratory at Gulf Breeze, Fla., and at Bears Bluff. S. C. showed this chemical to be toxic to decapod crustaceans, including juvenile blue crabs and penaeid shrimp (1 ■ 5. 6). Because of these and other results and concern of commercial fishermen that ap- plication of mirex to marsh areas could adversely aff'ect fishery resources, application of mirex to the coastal en- vironment was suspended and this cooperative study was undertaken. The Gulf Breeze Laboratory (formerly a biological laboratory of the Bureau of Commercial Fisheries, Fish and Wildlife Service. L'.S. Department of the Interior) entered an agreement with the U.S. Department of Agriculture in September 1969, to study the accumula- tion and movement of mirex in the estuarine environ- ment near Charleston. S. C. The Bureau of Sport Fisheries and Wildlife of the Fish and Wildlife Service also agreed to participate in the study which terminated July 1, 1971. The Gulf Breeze Laboratory was responsible for de- signing the study; collecting samples of bottom sediment, water, shrimp, crabs, and fish; and for analyzing all samples. The Bureau of Sport Fisheries and Wildlife was responsible for collecting birds and mammals. The purposes of this investigation were (1) to observe the possible movement of mirex from treated areas near Pesticides Monitoring Journal 'harleston, S. C, to the estuarine environment and (2) ) determine levels of mirex in organisms, particularly rabs and shrimp, before, during, and after treatment of le area. The investigation began approximately 1 week efore the first treatment was applied. Pretreatment imples were collected to establish "background" levels f mirex in the environment. The short time period be- veen the start of the investigation and the application f mirex. however, precluded studies necessary to de- irmine the ecological impact of this chemical on the udy area. Methods rUDY AREA he estuaries in which these studies were conducted order on a fire ant treatment area that extended 30 liles on either side of a line from Columbia to Charles- ton, S. C. The boundary of the treatment area ended approximately 12 miles from the coast (Fig. 1). Mirex, therefore, was not applied directly to the salt marsh, except in an experimental plot near Toogoodoo Creek. The topography and biota of the estuarine environment are unique and often present special problems to environ- mental studies. Estuaries along this portion of the East Coast of the United States are protected by barrier islands and are supplied silt-laden fresh water by creeks and rivers on the mainland. These typical "Spartina" marshes support transient populations of crabs, shrimp, and fish that develop to maturity in the estuary, then re- turn to the sea. In addition, resident populations of shell- fish and some fin-fish inhabit the estuary throughout their lives. Many predatory birds and mammals depend upon the estuarine organisms for food. MONITORING STATIONS GfO«G«TO«ni Tom „ ,~ y?' LAKE MOUITKK V-^J^V tv. O.S TREATED 'ooGooooo otei AREA . .^iCM"" ATLANTIC OCEAN ^^^, \ I I I Mt.ES CO*STAl SOUNOAWV FIGURE 1. — Siinipling siles in selected esluaiies of Soulli Carolina, 1969-7 1 OL. 7, No. 1, luNE 1973 Descriptions of sampling sites with the dates of mirex applications are given in Table 1 . Perodically, levels of mirex in water, sediment, and biota were monitored at (1) four stations near the main inland mirex-treated area and within and near a 2-square mile plot of salt marsh that was treated experimentally, (2) six stations located on the major rivers that drain the main inland mirex-treated areas, and (3) a station in a semi-enclosed tidal pond 4 miles from the main inland mirex-treated area; the banks of the pond (2.5 acres) were treated with mirex by hand spreader. APPLICATION OF MIREX The mirex 4X Bait formulation contained 84.7% corn- cob grits, 15.0% soybean oil, and 0.3% mirex. The bait was applied at a rate of 1.25 lb per acre or 1.7 g of technical mirex. This produced approximately 16 par- ticles of bait per square foot. TABLE I — Description of sampling sites and dates of mirex application. South Carolina. 1969-71 Map Location Number (Fig. 1) Name and Location OF Sampling Site Toogoodoo Creek Lat. 32° 41' N Long. 80° 18' W do. Remarks do. Riverland Terrace Pond Lat. 32° 46' N Long. 79° 59' W Stono River ( Inlracoaslal Waterway) at Log Bridge Creek Lat. 32° 45' N Long. 80° 08' W Ashley River at Runnymeade Plantation Lat. 32= 53' N Long. 80' 05- W Cooper River at U.S. Naval Ammunition Depot Lat. 32° 57' N Long. 79° 56' W Ashley River at Oldtown Creek Lat. 32" 48' N Long. 79° 58' W Wando River at Beresford Creek Lat. 32° .53' N Long. 79" 53' W South Santec River (Intracoastal Waterway) at Alligator Creek Lat. 32° 08' N Long. 79° 19' W Within the main inland mirex-treated area on the upper reaches of the left branch of the Creek. Tidal marshlands predominate along the north hank; pine woodlands lie to the south. Several homes are in the area. Also treated experimentally by helicopter. Begins at the mouth of Swinton Creek and continues east- ward on lower part of the Creek; partially within the mainland treated zone; marsh and woodland areas are on each bank. A few homes are along the south bank. Also treated experimentally by helicopter. Extends southward from the fork of Toogoodoo Creek, just south of the experimental area treated by helicopter. Extensive farmlands are on the west bank, lidal marsh- lands on the east. Begins 2 miles south of ihe helicopter-ireated area and continues to the mouth of Toogoodoo Creek on the Intracoastal Waterway. Uninhabited low marsh areas on both sides of the creek are riddled with many small tidal creeks. Seven miles from main inland treatment area, mcludes one of two adjoining 1-acrc ponds in Riverland Terrace (a residential area). The east pond floods and drains with the tides Into Wappoo Creek (Intracoastal Water- way), via iwo large culverts. The banks of the east pond were treated above the high tide mark by hand spreader. Two miles from main inland treatment area. Several homes along the east side of the creek; the west side is bordered by tidal marshes. f)ld plantations and rural homes are located on the east bank, and lidal marshes lie along the west side. This fresh water station is inside the main inland mirex-treated area. Bordered on the west bank by high wooded ground. On the cast side, tidal marshes predominate. This fresh water station is inside the main inland mirex-treated area. Six miles from the main inland treated area. The Citadel Military College is on the east bank. Charles Townc Landing on the west. Several industrial plants and homes, in addition to tidal marshes, are on this portion of the river. Six miles from the main inland treated area. This unin- habited area is bordered by expansive marshlands and marsh islands. Six miles from the main inland treated area. This location is uninhabited and near the Cape Remain Migratory Bird Refuge. Application Dates 1st 10/14-15/69 do. do. 12/3/69 10/23/69 10/22/69 10/17/69 10/22/69 10/17/69 9/18/69 2d 6/3-4/70 do. 3d 10/27-28/701 do. do. 12/1/70 6/18/70 6/11/70 6/10/70 6/10/70 6/8/70 5/20/70 Pesticides Monitoring Journ^ /lirex 4X Bait was applied by fixed wing multi-engine ircraft (PV-2) to the inland treatment area, hy heli- opter to the Toogoodoo experimental plot, and by hand preaders to the banks of a tidal pond. All applications 'ere supervised by USDA. that were often diflicult to obtain because of their transitory nature and movement to deeper water during the winter. In general, representatives of all species of aquatic organisms caught in the trawl were analyzed for mirex. Tie inland treatment area was divided into blocks that aried from 350,000 to 450,000 acres. An electronic uidance system (Decca .Survey System) was set up in ach block. This system consisted of three transmitting nd receiving stations (one master station and two slave :ations). The master and one of the slave stations pro- uced an electronic tracking signal. Equipment mounted 1 the application aircraft received this signal which was ;d through a computer into a dacometer. By use of the acometer, the aircraft pilot could follow the signal •om one point to another along the tracking path. Iniform application was made across each block by ying along a series of parallel signals. The master sta- on and the second slave station produced a ranging gnal that designated the points along the tracking path 'here the spraying was cut off". These signals, tracking nd ranging, were converted to a numbering system and le system oriented to a map of the area being treated. 'o allow for better control, helicopter applications of le mirex bait at the recommended rate were made to 00 acres of the 1,200-acre Toogoodoo Experimental ,rea. The Bell G-2-A helicopter used for spraying was ijuipped with two side-mounted hoppers (300 pounds ipacity each) with electrically operated hopper gates, ^itators, spinner-vane wheels, and spreaders for "posi- ve control" at the "cut-off point." Flying at an air- )eed of 40 miles per hour and an altitude of 80 feet reduced a 75-foot wide swath; at 40 feet, a 60-foot ide swath. Helium-filled kytoons were used to mark ich swath path. Bait distribution was even at both titudes, but wind caused considerable aerial drift. pproximately 2,5 acres surrounding the tidal pond ere treated three times at 6-month intervals by hand- lerated seed spreaders. \MPLING Materials Sampled ssticides entering the estuarme environment become irt of the biogeochemical cycles continually in opera- 3n within that environment. Therefore, the water, sedi- 1 ent, and various biota were sampled to determine >utes of movement and reservoirs of the chemical in e study area. Common and scientific names of aquatic iiimals, birds, and mammals collected for mirex an- I ysis are listed in Table 2. Crabs and shrimp were of lecial interest because of their sensitivity to mirex :ottom and filter-feeding fish were also collected since ey could accumulate mirex from food web organisms OL. 7, No. I, June 1973 In selecting the birds and mammals for residue analvsis, an effort was made to pick species that were (a) directly dependent on the estuarine environment for food; (b) most likely to live and feed in the area where they were collected; and (c) plentiful enough to allow periodic collections with a minimum of difficulty. The raccoon was selected as the mammal for sampling since it is the most abundant carnivore in the salt marsh, where it preys heavily upon crustaceans and shellfish. It was more difficult to decide upon a bird species. Numerous gulls, shore birds, wading birds, and other water birds are found in the estuarv, but most of them are migrator}' by nature, moving up and down the coast in search of food or as a result of weather changes. Few water birds are year-rountl residents. The clapper rail was finally selected as the most sedentary and widely distributed bird in the estuaries; when rails were not available at a particular sampling station, wading birds were collected. All animals collected during this study are listed in Table 2. Collection of samples Aquatic animals were collected with a I 2 -foot, '4 -inch bar mesh, otter trawl towed at 3 to 6 knots for 20 minutes at each station. Pond collections were made with a 15-foot. '.4 -inch mesh haul seine. Occasionally, animals near the surface were taken with dip nets; fidder crabs and oysters were collected by hand. Raccoons were captured with wire live-traps; birds were hunted on foot or from a boat. -Several methods for collecting water (including carbon filtration) were considered, but because of the high silt content of the well-mixed water, water was collected just below the surface in a I -gallon glass jug and sealed with a teflon-lined cap. A modified grab sampler was used to collect bottom sediment at each station. A sampler especially designed to collect the upper few centimeters of bottom .sediment was used in specified instances. Frequency of sampling A pretreatment (background) and numerous posttreat- ment samples were taken at all stations. Quarterly collec- tions of birds and mammals were scheduled around the first week in September. December. March, and June. Periodically, this schedule was altered by 2 or 3 weeks to select the week of highest tides for the best TABLE 2, — Common and scientific names of aqiialic animals, birds, and mammals collected for mirex residue analysis CRABS Blue crab Callinecles sapidiis Rathbun Common mud crab Panopeus herhstii H. Milne Edwards Mud crab Rithropanopctis harrisii Gould Portunid crab Callinecles ornanis Ordway Sand fiddler llcd piigilawr (Hose) FISHES— Continued American eel Atlantic croaker Atlantic menhaden Atlantic silversidc Atlantic thread herring Bay anchovy Blackcheek tonguehsh Black drum Black sea ba^\ Bluefish Fourspot flounder Hopchoker Mummlchop Pinfish Sailfin moLIy Sea catfish Searobin Sheepshead Silver perch Snook Southern kingfish Spot Spotted hake Spotted seatroul SHRINfPS Brown shrimp Pcnaeus aztecus Ives Brown-spotted shrimp Pcnaeus duoranim Burkenrojid Grass shrimp Paiaemoneles puRto Holthuis River shrimp Macrohrachium ohionc (Smith) White shrimp Penaeus setiferus (Linnaeus) FISHES Anguilla Tostrata (Lesueur) Micropogon utrdulatu.'i ( Linnaeus ) Bre\ oortia lyrannus (Latrobe) Menidia mcuidia ( Linnaeus ) Opisthonema oglinum (Lesueur) Anclioa mitchilli (Valenciennes) Symphurus plaKiusa (Linnaeus) Poffonias cromis (Linnaeus) Ccntropristis striata ( Linnaeus ) Pomatomus saltatrix (Linnaeus) Parallchthys ohlongus (MitchilU Trincites maciilatus (Bloch and Schneider) f imdubis heteroclitus (Linnaeus) Lagodon rhomboides (Linnaeus) Poccilia latipinna (Lesueur) Arius felis ( Linnaeus) Priouoius sp. Archosargus prohatocephalu^ ( Walbaum) fiairdiella chrysura Lacepede Ccnlropoinu.s undccimali.s ( BIocli ) Mcnticirrhus anicricaniis ( Linnaeus ) Lciostomus xanfhurus Lacepede Urophycis regius (Walbaum) Cynoscion nchulosus (Cuvier and Valenciennes) Star drum Siellifer lanceolatus (Holbrook) Striped kilHfish Fundulus majalis (Walbaum) Striped mullet Miigil cephalus Linnaeus Weakfish Cyrwsciofi regalis ( Bloch and Schneider) White catfish Icralurus catus (Linnaeus) While mullet Mugil curcma Valenciennes Winter flounder Pscudoplcurotiectcs americanus (Walbaum) MISCELLANEOUS AQUATIC ANIMALS American oyster Crassostrea virginica (Gmelin) Brief squid Lolliguncula brevis (Blainville) Nudibranch Oori.K sp. Southern periwinkle Littorina irrorata (Say) BIRDS American bittern Botaurua lentiginosus ( Rackett ) American egret Casmerodius albiis (Linnaeus) Anhinga Anhinga anhinga (Linnaeus) Belted kingfisher Mcgaceryle alcyon (Linnaeus) Clapper rail Rallus longiro.slris Boddgert Common snipe Capella gallinago (Linnaeus) Green heron Butorides virescens (Linnaeus) Least bittern Ixobrychus cxilis (Gmelin) Little blue heron Florida caerulea (Linnaeus) Louisiana heron Hydranassa tricolor (Miiller) Marsh hawk Circus cyaneus (Linnaeus) Pied-billed grebe Podilymbiis podiceps (Linnaeus) Plover Charadrius sp. Snowy egret Leucophoyx thula (Molina) Sora rail Porzana Carolina (Linnaeus) Virginia rail Rallus limicola Vieillot White ibis F.iidocimus albus (Linnaeus) Willet Catoptrophorus semipalniatus (Gmelin ) Yellow-crowned night heron Nyctanassa \iolacea (Linnaeus) MAMMALS Opossum Raccoon DidelpUis \ irginiana (Linnaeus) Procyon lotor (Linnaeus) rail hunting. Samples were taken at the six river stations 24 hours and 3 months after each of two applications of mirex to the inland treatment area by fixed wing aircraft. Biweekly collections were made at the four stations in the Toogoodoo Creek Plot during the entire 18 months of the study; mirex was applied to the ex- perimental plot by helicopter three times at 6-month intervals to high marsh only. i.e.. marsh not normally covered by tidal waters. Samples were taken from the tidal pond 24 hours after each of three hand-spread treatments and at irregular intervals between applica- tions. ANALYTICAL PROCEDURES Preparation of samples Crabs, shrimp, and fish were prepared separately by pooling whole individuals, but birds and mammals were 10 prepared individually. Muscle tissue from breast and upper wing in birds and thigh in raccoons and oil glands and eggs from birds were analyzed. All samples were ground and mixed thoroughly in a blender. A 30-g subsample was blended with a desiccant mix composed of 10% QUSO (a microfine precipitated silica) and 90% anhydrous sodium sulfate. This mixture was al- ternately frozen and blended until a free-flowing powder was obtained. Sediment samples were spread on sheets of aluminum foil and dried at room temperature. The dry sediment was pulversized to a fine powder in a blender. At this stage of preparation, the samples were wrapped in aluminum foil, packaged in plastic bags, and mailed to the Gulf Breeze Laboratory for extracting and pesticide residue analysis. Pesticides Monitoring Journal A'ater samples were refrigerated for up to 2 weeks jntil they were mailed to Gulf Breeze for analysis. Analysis of samples Tissues of shrimp, crabs, and fish mixed with the desiccant were extracted for 4 hours with petroleum ether in a Soxhlet apparatus. Extracts were concentrated to approximately 10 ml and transferred in }- to 4-ml portions to a 400-mm by 20-mm chromatographic column that contained 76 mm of unactivated Florisil. After each portion settled in the column, vacuum was applied to evaporate the solvent. This was repeated after each addition and after three 5-ml petroleum ether rinses of the extraction flask. The vacuum pump was disconnected after all solvent had evaporated, and the residue was eluted from the column with 70 ml of 9: 1 mixture of acetonitrile and distilled water. The eluate was evaporated to dryness and the residue transferred to a Florisil column (7) with petroleum ether. Sediment samples were dried at room temperature and extracted for 4 hours with 10% acetone in petroleum ether in a Soxhlet apparatus. Extracts were concentrated to approximately 10 ml and transferred to a Florisil column (7). Water samples were not filtered before being extracted with petroleum ether. The extracts were dried with anhydrous sodium sulfate and reduced to an appropriate volume. The extracts of all substrates were identified and meas- ured by electron capture gas chromatography. Extract volumes were adjusted to obtain a sensitivity of 0.01 ppm (mg/kg) for tissue and sediment samples and 0.01 ppb (/ig/liter) for water samples. Operating conditions of the two 152.4-cm by 3.2-mni glass columns used were: Liquid phase; Solid Support: Temperatures: Oven: Injector and detector: N; flow rate: Laboratory tests indicated recovery rates for mirex were greater than 85%. Data in this report do not include a correction factor for percent recovery. All residues re- ported are on a wet-weight basis, except those of sedi- ments, which are reported on a dry-weight basis. Thin layer chromatography, "p" values, and mass spectro- metry were used to confirm the presence of mirex. STATISTICAL ANALYSIS OF DATA All statistical comparisons were made with the x--test for independent samples (5), and differences were consid- VoL. 7, No. 1, June 1973 17c OV-101 1:1 27^ OV-101 100/120 Gas 100/120 Gas Chrom Q Chrom 0 188° C 180° C 210° C 210° C 25 ml/niin 25 ml min ered real at the 0.01 level of significance. The move- ment of mirex into the aquatic environment and its consequent accumulation in populations of estuarine animals were presumed to be greatest in areas where a significantly greater proportion of samples was positive for mirex OO.Ol ppm). Average residues reported were computed by assuming that samples where mirex was not detected «0.01 ppm) actually had no residue. Bird and mammal residue data were not analyzed statis- tically; however, average mirex residues in muscle tissues are tabulated for herons and egrets (Table 10), clapper rails (Table 11), and raccoons (Table 13). Results PRETREATMENT SAMPLES Mirex was not detected in any pretreatment samples of crabs, shrimp, fish, sediment, or water taken from the six monitoring stations. Toogoodoo stations, or the Riverland Terrace pond. Mirex residues were found in about one-third of the pretreatment samples of migra- tory birds (Table 9). Only one raccoon was collected before treatment, and this sample was free of mirex residues. Background residues in birds collected in the Charleston area are discussed in the section on "Signifi- cance of Data." WATER AND SEDIMENT SAMPLES Mirex was not detected in water samples during the study. No attempt was made, however, to concentrate water samples (such as carbon filtration of large volumes of water). Sediment samples were negative, except in six instances (three samples from Riverland Terrace pond and three from the Ashley River within the treated zone). Ac- cordingly, mirex residues in water and sediment are not reported in tabular form ACCUMULATION OF MIREX IN BIOTA Biological concentration of mirex occurred in estuarine food web as shown below: the RtiSiDUi: RANcr. (ppm) Percent of Posttreatment Samples with Mirex Residues Water Sediment Crabs Fishes Shrimps Mammals Birds < 0.01 ppb 0*-0.07 0-0.60 0-0, s: 0-I..1 0-4,4 0-17.0 0 3 31 15 to 54 78 •0=<0.01 ppm Differences in the amounts of mirex accumulated by the animals were probably caused by variables such as proximity to the treated area, duration of exposure to a 11 mirex-contaminated habitat, seasonal habits, avoidance ability, and position in the food web. Additional variation may depend upon parameters such as method of application, amount and frequency of rain- fall, surface runoff, variations in sea level, and degrada- tion. Levels of mirex found in the biota are listed in Tables 5 to 14. Discussion ANIMAL MORTALITIES Procedures used in this study were neither capable of. nor intended to comprehensively detect mortality of aquatic organisms. The sampling areas were, however, inspected for dead or affected animals during each sampling period, and mass mortalities would probably have been detectetl visually or in trawl catches. No mass mortalities of organisms were observed during the study. Our laboratory experiments (5) suggest that mortalities in a population of marine crustaceans due to mirex would not all occur at Ihe same time. Symptoms of mirex poisoning exhihilctl by shrimp and crabs prior to death are irritability, uncoordinated movement, loss of equilibrium, and paralysis. An affected crab may live several days or even weeks after ihc initial exposure to mirex. Animals in advanced stages of poisoning would be highly susceptible to predation bv larger carnivores and could be swept out of estuaries b\ tidal action. Thus, affected animals could he removed from the system without leaving visible evidence of their condi- tion. Further, any tiead animals would pencralK enter the detritus pool soon after death rOOGOODOO CREEK EXPERIMENIAI AREA— 1 ,20()-acie plot (Fit,'. I) ticaled h\ hclicopwr on Oct. 14-15. /960; June ?-4. 1070: aiul O, i :^7-:!S. 1970 Movement of mirex from Irc.ilcd lands above the high- tide mark undoiibtedK occurred after each of the three treatments, cspecialls ilic first. The mechanisms of transporting mirex from treated land areas to the Toogoodoo Creek estuary are poorly understood. Sur- face runoff into the drainage system (especiallv after heavy rain) is one suspected cause. All species sampled conl.unetl mirex. Residues first appeared in a shrimp sample 2 weeks after the first treatment. From then (mi. the relative frequencv of mirex-posilive samples and the "average" levels of mirex residues (luclualed greatly. Mirex was presenl. however, in at least one sample in .L^ of 44 collections. Some of the statislicalK' significant relationships occur- ring within these fluctuations are discussed in the follow- ing paragraphs. Application effects The relative number of samples that contained mirex appeared to increase during the first 10 weeks after each treatment and then to decrease in the 10- to 20-wcek period (Table 3). After the first and third treatments, the number of positive samples appeared to decrease even further in the third interval, 20 to }<2 weeks. The.se decreases for each individual treatment were not statistically significant; however, when data from all treatments were evaluated together, the relationship be- tween time elapsed since spraying and the decreasing number of positive samples provcti to be real. Decreases in the percent occurrence of mirex residues from the first to the third treatment were significant. This could be due to: (1) mirex being translocated rapidly from the estuarine biota to reservoirs in fatty tissues of predacious birds and mammals, (2) transient estuarine animals (e.g., crabs, shrimp) translocating mirex during emigration from nursery areas of Toogoo- doo Cree'C. (3) possible differences in the manner in which mirex bait was applied by the two helicopter pilots, or (4) degradation of mirex by physical, chemical, or biological processes. Location effects The relative number of samples positive for mirex also fluctuated with station location. Stations A and B were located within the treated area, and Stations C and D were downstream from the treated area (Fig. I). Mirex levels at these stations gave some indication of the move- ment of mirex from treated land areas into untreated areas downstream. As expected, more animals from the treated area con- tained mirex than did those from downstream stations (Table 4). This relationship was statistically significant after the first and third applications, but was only ap- parent after the second treatment. The frequencies of positive samples al stations located within the treated zone (A and B) were not significantly dilTerent. As shown in Table 4, there was an apparent decrease in frequency of positive samples with increased distance from the treated zone. S'p<( icy cfjcn^ The percent occurrence of mirex was higher in crab samples than in fish or shrimp samples. Although this difl'erence was apparent at Stations A through D, it was statistically significant only al Station B. Overall, how- ever, the higher residues in crabs were significant after the first two helicopter treatments, hut was not statisti- cally significant after the third treatment. The frequency of positive samples appeared unrelated to size of crabs or to species of fish. 12 PtiSTiciDEs Monitoring Journal TABLE 3. — Percent occurrence of mirex in crab, shrimp, and fish samples by time of sample collection in respect to mirex application at Toogoodoo Creek Experimental Area Application Percent Occurrence of MreEX by Sampling Time in Weeks Since Application 0-10 10-20 20-32 Total Weeks First (Oct. 14-15, 1969) ■ Second (June 3-4, 1970) Third (Oct. 27-28, 1970) 37 22 28 36 9 12 18 2 30 (0-32 weeks) 16 (0-20 weeks) 12 (0-32 weeks) Overall Percent Occurrence 28 17 8 19 TABLE 4. — Percent occurrence of mirex in aquatic animals by sampling site with respect to treated area Sampling Site Location wrrH Respect to Treated Area Percent Occurrence Mirex in All Post- Treatment Samples OF Crabs, Shrimp. AND Fish A B C D Inside treated area Inside treated area Just outside treated area 2 miles downstream from treated area 29% 24% 17% 8% 3 4 Upstream stations located main inland treated area inside 70% 70% 2 5 6 7 Downstream stations located out- side main inland treated area 30% 0% 25% 0% MONITORING STATIONS— w/rex was applied to inland treatment areas (Fig. 1) by fixed-wing aircraft during September-Ocotber 1969 and May-June 1970 Trends in the data were similar to those observed in the Toogoodoo Creek E.xperimental Area. The greatest number of positive samples occurred shortly after treat- ment and diminished with time. Samples positive for mirex were significantly more frequent within the treated area, upstream Stations 3 and 4, than at sites located outside the treated area, downstream Stations 2, 5, 6, and 7 (Table 4). Although significant differences in percent occurrence were noted between these two groups, individual stations showed no significant differences because too few samples were taken and too few positive samples oc- curred for x--analysis. Also, for the individual monitor- ing stations, the relative number of samples containing mirex did not vary depending on the type of animal sampled. A more frequent occurrence of mirex residues was apparent after the second application than after the first, but this increase was not significant. Vol. 7, No. 1, June 1973 RIVERLAND TERRACE POND— a 2.5-acre zone around the pond treated by hand-operated seed spreader on Dec. 3, 1969; July 24, 1970; and Dec. 1, 1970 Although mirex was applied three times to the banks of the pond, it was obviously not accumulated by sampled biota. During the study, only two crab samples con- tained mirex. In addition, three sediment samples were positive. The method of treatment (mirex applied by hand to a narrow bank around the pond above the high- tide mark on hard mud banks) might have caused the occurrence of the mirex in the sediment samples. "Crab samples" of sediment often consisted of as many as 20 to 25 "grabs" taken near the edge of the pond and one or more particles of bait could have been picked up with the sample. Special attention was given Riverland Terrace Pond to observe any individual- or mass-mortalities in the pond biota. Migration of animals was controlled by means of retaining screens (>4-inch mesh) placed over two cul- verts that flood and drain the treated pond. Daily screen checks were made for a 3-week period to reveal any distressed, moribund, or dead animals. Crabs, shrimp, and fish observed in the pond or on the screens never appeared to be affected. During several pond collections after treatment, seine- hauls revealed large populations of grass shrimp (mostly Palaemonetes pugio) and many of the females were gravid. On one occasion, grass shrimp were held for several weeks in an aquarium, where the shrimp re- mained healthy and their eggs seemed to develop and hatch normally. At no time was mirex detected in the grass shrimp population. SIGNIFICANCE OF DATA Surprisingly, mirex appeared in one-third of the birds in the pretreatment sample. Since the study area had not been previously treated with a large-scale applica- tion of mirex. the birds must have accumulated the residues from some other area. A large acreage around Savannah, Ga.. had been treated with three successive applications of mirex in a pilot study of the feasibility of eradication. This area is the likely source of the mirex residues. Thus, migration is an important factor in in- terpreting the study data. Stewart's (9) report that northern clapper rails banded at Chincoteague, Va. migrated southward to winter in the coastal marshes of the South Atlantic States, including South Carolina, sup- ports this view. Measurable levels of mirex appeared at all stations, demonstrating that tidal flushing, biological transport, or some other mechanism can distribute the chemical throughout the estuary, regardless of precautions taken 13 to avoid treatment in the tidal zone. This finding is evidence that mirex can become widespread in animal food webs. The occurrence and amount of mirex in birds and mam- mals varied considerably at all stations. This is to be expected since all of these animals are more or less migratory, and food sources of individuals vary. Simi- larly, Keith (4) found that levels of insecticide residues in fish-eating birds vary considerably within local popula- tions of most species. Even so, average residues that appeared at the different stations correlated well with station location in respect to treated area, with the highest residues occurring at stations within a treated area and the lowest at stations farthest from the source of contamination. Approximately 78% of the 179 birds collected after treatment began contained measurable residues of mirex, whereas residues were present in only 54% of the raccoons. The greater mobility of birds is doubtless the reason for this diff'erence. In any case, occurrence of mirex residues as well as the quantity of residue in the animal appear directly related to drainage and distance from a treated area. Residues in animals collected from the 2-square-mile treatment area on the Toogoodoo creek marshes (Sta- tions A. B, and C) were not as great as those from animals collected within the inland treatment zone. This is not surprising because water as well as food-chain organisms in the Toogoodoo marshes were flushed twice daily by 4- to 6- foot tides. Local and seasonal migrations of the sampled species would tend to mask any evidence of residue buildup during the course of the study. Even so. the absence of any individuals with greatly elevated residue levels in- dicates that average levels did not continue to rise beyond levels reached in the first few months following treatment. Raccoons were the most sedentary animals sampled. Data in Table 12 indicate that there was no gradual buildup of mirex residues in raccoons, although some seasonal variations are apparent. The highest mirex residue (17.0 ppm) found in any animal analyzed occurred in a kingfisher. The highest level found in a raccoon was 4.40 ppm. All birds and mammals that contained residues in excess of 1.00 ppm are listed in Table 14. All animals on this list, except the kingfisher from Station D and two raccoons from Sta- tion 2, came from stations classified as having a "high" mirex exposure potential. See Appendix for chemical name of mirex Acknowledgment Special thanks are due Dr. Nelson Cooley for editorial help, Dave Hansen for assistance with statistical an- alysis, Jerry Forester and Johnnie Knight for analysis of samples, and Madeleine Brown and Steve Foss for assistance in manuscript preparation— all of the Gulf Breeze Environmental Research Laboratory, U.S. En- vironmental Protection Agency. We also thank the following persons who supervised the application of mirex or approved or conducted various aspects of the collection and preparation of samples: Julian Mikell, Plant Protection Division U.S. Depart- ment of Agriculture; Charles Bearden and Michael I McKenzie, Division of Marine Resources, S.C. Wildlife • Resources Department; Alston Badger, Bears Bluff Field Station, U.S. Environmental Protection Agency; Frank McKinney, Grice Marine Biological Laboratory. College of Charleston. LITERATURE CITED (1) Bookhoiit, C. G., A. J. Wilson. Jr.. T. W. Duke, and J. 1. Lowe. 1972. Effects of mirex on the larval develop- ment of two crabs. Water. Air. Soil Pollut. 1(2): 165-180. (2} Carson. R. 1962. Silent Spring, p. 161-169. Houghton i Mifflin Co., Boston, Mass. 13} Frear. D. E. H. 1969. Pesticide Index, 4th ed. 399 p. College Science Publishers, State College, Pa. 16801. (4) Keith. J. O. 1968. Insecticide residues in fish-eating birds and their environment. Aves 5(1):28-41. (5) Lowe, J. /., P. R. Parrish. A. J. Wilson, Jr.. P. D. Wilson, and T. W. Duke. 1971. Effects of mirex on selected estuarine organisms. In Transactions of the 36th . North Am. Wildl. Natl. Resour. Conf. p. 171-186. (6) McKenzie, M. D. 1970. Fluctuations in abundance of the blue crab and factors affecting mortalities. S. C. Wildl. Resour. Dep.. Marine Resour. Div., Tech. Rep. No. 1, 45 p.. Charleston. S. C. (7} Mills. P. A.. J. H. Onley. and R. A. Gaither. 1963. Rapid method for chlorinated pesticide residues in nonfatty foods. J. Assoc. Off. Anal. Chem. 46(2):186-191. 18) Siegel. S. 1956. Nonparametric statistics for the be- havioral sciences. McGraw-Hill Book Co., Inc., New York, N. Y. (9) Stewart, R. E. 1954. Migratory movements of the north- ern clapper rail. Bird Banding 25(1): I -5. 14 Pesticides Monitoring Journal TABLE 5.- -Mirex residues in sixrimps by sampling site and sampling time. South Carolina. 1969-71 [ — = not detected] Size of Mir EX Size op MiREX P^^JItl'^v NUMBER IN Individuals Residue INTERVAL NUMBER IN FROMMmEX COMPOSITE Individuals Residue Species FromMirex coMPosm- IN CoMPOsrrE (PPM — Species in Composite (PPM — APPLICATION Sample Samples WHOLE Application Sample Samples WHOLE ID Sampling (INCHES) BODY) TO Sampling (inches) BODY) SAMPLING SITE A- -TOOGOODOO CREEK SAMPLING SITE C- -TOOGOODOO CREEK White shrimp Background 3 2.5 — White shrimp Background 3 5 — First application First application (Oct. 14-15, 1969) (Oct. 14-15, 1969) White shrimp 24 his 4 2.5 — White shrimp 24 hrs 6 4-5 — 2 wks 4 2.5 — 2 wks 4 3 — 4 wks 10 4-5 .014 4 wks 10 4-5.5 .020 Brown shrimp 30 wks 13 2.5-3.5 — 6 wks 10 3.5-4 .014 Brown-spotted shrimp 32 wks 10 3.5-4 — Brown-spotted shrimp 30 wks 1 5.5 — 32 wks 3 6-7 — Second application (June 3-4, 1970) Second appUcation Brown-spotted shrimp 24 hrs 12 3.5-5.5 .014 (June 3-4, 1970) 2 wks 12 5-5.5 — Brown-spotted shrimp 24 hrs. 9 4-5 .015 4 wks 12 5.5-6 — 2 wks 12 3-5 — 6 wks 12 5-6 .024 4 wks 12 4-6 — 8 wks 12 3.5-5 — 6 wks 12 5-6 — White shrimp 10 wks 12 3.5-4.5 — 8 wks 4 4 — 12 wks 12 2.5-3.5 — White shrimp 10 wks 1 4.5 — 14 wks 12 3-4.5 — 12 wks 12 2.5-4 — 16 wks 12 4-4.5 — 14 wks 12 4.5-5.5 — 18 wks 11 5.5-6 — 16 wks 12 4-4.5 — 20 wks 12 5-6 — 18 wks 20 wks 12 10 5.5-6 5-6 — Third application (Oct. 27-28, 1970) Third application White shrimp 24 hrs 12 5-6 — (Oct. 27-28, 1970) 2 wks 4 5-6 — White shrimp 24 hrs 12 5-6 — Brown-spotted shrimp 20 wks 5 2.25-2.5 — 2 wks 10 5-7 — 24 wks 5 2.5-3.5 — Brown-spotted shrimp 20 wks 4 3.5-4.5 — 28 wks 30 wks 4 12 3.5-4.5 2.5-5 z Grass shrimp 24 wks 132 .75-1.25 - 32 wks 12 2-4 Brown-spotted shrimp 26 wks 9 3.5-5.5 — 28 wks 30 wks 32 wks 12 12 12 3.5-5 4-5 3.5-5 — SAMPLING SITE B- -TOOGOODOO CREEK — White shrunp Background 4 3 First application SAMPLING SITE D— TOOGOODOO CREEK (Oct. 14-15, 1969) White shrimp Background 2 6 — White stiiimp 24 hrs 4 3 — 2 wks 4 3-4 .040 First application 4 wks 10 4-5 .052 (Oct. 14-15, 1969) Brown-spotted shrimp 30 wks 32 wks 2 3 3-5 4 — White shrimp 24 hrs 2 wks 2 2 5 4,5 — 4 wks 7 5-6 — Second application 6 wks 10 4-5 — (June 3-4, 1970) 8 wks 15 3.5-5 .027 Brown-spotted shrimp 24 hrs 12 5-6 — Brown-spotted shrimp 24 wks 2 4.5-5 — 2 wks 12 5-5.5 — 30 wks 2 3-3.5 — 4 wks 2 4-6 — 6 wks 5 4-7 — Second application 8 wks 12 4-5 — (June 3-4, 1970) White shrimp 10 wks 12 3-4 Brown-spotted shrimp 24 hrs 12 4-5 — 12 wks 12 2-3 — 2 wks 12 5-6 — 14 wks 12 3.5-4.5 — 4 wks 2 5 — 16 wks 12 4-4.5 — 6 wks 12 5-6 — 18 wks 12 5-6 — White shrimp 10 wks 4 3.5-5.5 — 20 wks 12 5 — Brown-spotted shrimp 12 wks 12 3-4.5 — Third application White shrimp 14 wks 12 4.5-5.5 — (Oct. 27-28, 1970) 16 wks 12 4-5 — White shrimp 24 hrs 2 wks 12 3 5-6 4.5-6 — 18 wks 20 wks 12 10 5.5-6 5-6 — Brown-spotted shrimp 18 wks 3 3-4.5 — Third application 22 wks 5 2-4 — (Oct. 27-28, 1970) 24 wks 10 3-4 26 wks 4 3-4.5 White shrimp 24 hrs 12 5-6 — 28 wks 12 3-5.5 — 2 wks I 4.5 — 30 wks 11 2.75-5 — Brown-spotted shrimp 20 wks 2 5 — 32 wks 12 3^.5 — 24 wks 6 3.5-4.5 — Vol. 7, No. 1, June 1973 15 TABLE 5.- —Mirex resid les in si rimps by sampling sit [- = I Size of MlKEX INTERVAL NUMBER IN Individuals Residue SPEcres FROM MIREX COMPOSITE in CoMPosrrE (PPM— Application Sample Samples whole TO SAMPLING (INCHES) BODY) SAMPLING SITE D— TOOGOODOO CREEK— Continued Grass shrimp 24wks 100 .75-1.25 26wks 12 2.5-4 — 28wks 12 3-4 — 30wks 1 4.5 — 32wks 6 3.5-5.5 — STATION I— RIVERLAND TERRACE POND (EAST) Grass shrimp Background 178 .75-1 - First application (Dec. 3, 1969) Grass shrimp 48hrs 144 .75-1 — 5 mos 77 I — Grass shrimp Background 100 .75-1.25 - Second applicatior (July 24, 1970) White shrimp 72hrs 5 2-3 _ Grass shrimp 3 mos 146 1-1.25 — Brown-spotted shrimp 3 mos 5 2.25-3 — Grass shrimp 4 mos. 176 .75-1.25 - Third application (Dec. 1, 1970) Grass shrimp 48hrs 159 .75-1.25 — 2wks 167 .75-1.25 — 6 wks 193 .75-1.25 — 3 mos 126 .75-1.25 — STATION 2— STONO RIVER. LOG BRIDGE CREEK White shrimp Background 13 Medium Brown shrimp Background 9 Small — First application (Oct. 23. 1969) White shrimp 24hr5 4 3-4 — shrimps by sampling site and sampling lime, South Carolina, 1969-71 — Continued not detected] Second application (June 18, 1970) Brown-spotted shrimp 24 hrs White shrimp 3 mos 4.5-5.5 3.5-4.5 STATION 3— UPPER ASHLEY RIVER. RUNNYMEADE PLANTATION River shrimp Background First application (Oct. 22, 1969) Second application (June 11, 1970) Brown-spotted shrimp 24 hrs White shrimp 3 mos 3-4 4.5 Species Interval FROM Mirex Application to Sampling Size of MiREX Number in Individuals Residue Composite IN Po^'DosiTE (PPM— Sample Samples whole (INCHES) BODY) STATION 4— COOPER RIVER, U.S. NAVAL AMMUNITION DEPOT 3 2.5-3 First application (Oct. 17, 1969) River shrimp 24 hrs White shrimp 24 hrs Second appUcation (June 10, 1970) White shrimp 3 mo 1.3 .26 3-4.5 STATION 5— LOWER ASHLEY RIVER, OLD TOWN CREEK White shrimp Background 6 4 First application (Oct. 22, 1969) White shrimp 24 hrs 4 3-4 Second application (June 10, 1970) Brown-spotted shrimp 24 hrs White shrimp 3 mos 3 7 2.5-3 3-6 STATION 6— WANDO RIVER, BERESFORD CREEK White shrimp Background 4 4.5-5.5 First application (Oct. 17, 1969) White shrimp 24 hrs 3 4-6 Second application (June 8, 1970) Brown-spotted shrimp 24 hrs 12 3.5-4.5 White shrimp 3 mos 12 3.5-4 8 mos 12 3.5-5 .015 STATION 7— SOUTH SANTEE RIVER, ALLIGATOR CREEK White shrimp Background 8 2.5-4 First application (Sept. 18, 1969) White shrimp 24 hrs 9 2-2.5 Second application (May 20, 1970) Brown-spotted shrimp 3 mos 12 3.5-4 White shrimp 8 mos 12 4.5-5 16 Pesticides Monitoring Journal TABLE 6. — Mirex residues in crahs ti\ sampling site and sampling lime. Soiitli Carolina. I '^60-71 \ — — not detected] Size of MiREX Size of Mirex INTERVAL ^^„^^^ ,^ FROMMmEX COMPOSITE APPLICATION s^^pj^^ Individuals Residue INTIRVAI ^ t;MHI R IN Individuals Residue Species IN Composite Samples (PPM — WHOLE ^ FkUM IVllKL.X f S'''^'^'" APPLICATION '- omposite Sample IN Composite Samplls (PPM — whole TO Sampling (INCHES) BODY) TO Sampling (INLnbs) body) SAMPLING SITE A- -TOOGOODOO CREEK SAMPLING SITE B— TOOGOODOO CREEK— Contir ued Blue crab Background 1 5 — Third application (Oct. 27-28, 1970) First application Blue crab 24 hrs 6 1-2.5 .049 (Oct. 14-15, 1969) Fiddler crab 24hrs 30 .33-.75 Blue crab 24hrs 2 3 — Blue crab 4 wks 2 3-5 .012 4 wks 5 1-2.5 .12 6 wks 11 1-2.5 .12 12 wks 2 4.5-5 .19 Fiddler crab 6 wks 29 .33-. 75 14 wks 1 4.5 .12 Blue crab 8 wks 5 1-2 .041 16 wks 1 2.5 .19 10 wks 4 1.5-5 .027 22 wks 3 1-3 .040 12 wks 3 .75-3 .038 26 wks 4 3-4 .015 14 wks S .75-2 28 wks 2 3-4 .026 16 wks 9 2-5 .020 30 wks 4 3-6 .016 18 wks 20 wks 7 9 1.25-2 1-2 — Second application 22 wks 4 2-4 {June 3-4, 1970) 24 wks 12 1.5-2.5 — Blue crab 24hr5 3 2-3 _ 26 wks 4 1-4.5 — 4 wks 5 2.5-5 .19 28 wks 5 3-6 — 6 wks 3 3-6 32 wks 1 3.5 — 8 wks 10 wks 5 8 2-5 5-6 .052 .053 SAMPLING SITE C- -TOOGOODOO CREEK 12 wks 14 wks 12 1 5-2 5 12 2-2.5 — Bluc crab Background 1 5 16 wks 6 2.5-5.5 — 18 wks 1 5.5 .024 First application 20 wks 5 1-5 — (Oct. 14-15, 1969) Blue crab 24 hrs 1 6 Third application (Oct. 27-28, 19701 2 wks 4 wks 1 9 6 1-2 — Blue crab 24hrs 3 6 — 6 wks 4 2-3 .015 2 wlu 3 1-5 — 8 wks 1 6 .032 4 wks .3 2-5 12 wks T 5.5 .090 6 wks 11 1-2 .013 14 wks 1 2 .050 8 wks 12 1-2.5 IS wks 20 wks 2 4.5 4.5 .056 .025 10 wks 7 1-3 — 22 wks 8 1-2 .038 14 wks 12 1-1.25 — 24 wks 2 1-2 16 wks 10 1-1.75 .022 26 wks 1 3 18 wks 6 1.5-2 _ 28 wks T 4-5 — 20 wks s 1.25-1.5 30 wks 1 4 — 22 wks 8 1-3 — Fiddler crab 32 wks 25 .5-1 — 24 wks 26 wks s 5 3.5-5 1.5-3 .016 .Second application (June 3-4, 1970) 28 wks 1 2.5 — 30 wks 2 3.25-4.5 _ Blue crab 24 hrs 1 4.5 .013 32 wks 5 2-5.5 — 2 wks 6 wks 8 wks 3 6 4 6-6.5 3-4.5 4-5 .027 SAMPLING SITE B- -TOOGOODOO CREEK — 12 wks 4 2-4 Blue crab Background 1 6 — 14 wks 16 wks 1 2 5 4.5 - First application 20 wks 2 6 (Oct. 14-15, 1969) Fiddler crab 21 wks 26 .5-.75 Blue crab 24hrs 4 wks 8 wks 1 I 1 6 6 3 .24 .089 Third application (Oct. 27-28, 1970) 14 wks 1 3 .20 Blue crab 24 hrs 3 3-5 — 18 wks 2 4.5 — Fiddler crab 24 hrs 27 .5-.75 26 wks 2 3-4 — Blue crab 2 wks 1 6 32 wks 3 4-6 .025 4 wks 6 wks 3 4 4-5 4.5 .010 Second application Fiddler crab 6 wks 31 .5-1 (June 3-4, 1970) Blue crab 8 wks 4 1.5-2.5 Blue crab 4 wks 6 2.5-5 .035 14 wks 3 1-1.75 8 wks 3 2-6 — 16 wks 7 1-2.5 10 wks 4 4-5 .017 20 wks S 1-2 12 wks 12 1.25-2.25 — 22 wks 2 1.5-2.5 — 14 wks 6 3-5,5 — 24 wks 7 1.5-3 — 16 wks 1 5 — 26 wks 8 1-2.5 — 18 wks 1 5.5 — 28 wks 8 1.25-3.25 — Fiddler crab 21 wks 28 .33-.75 — 30 wks 1 2 — Vol. 7, No. 1, June 1973 17 TABLE 6. — Mirex residues in crabs by sampling site and sampling time, South Carolina, 1969-71 — Continued ( — =; not detected] Size of Mirex Size of MiREX Interval numbek in Individuals Residue INTERVAL ^^^^^^ ,^ INDIVIDUALS Residue SPECIES FROM MIREX COMPOSITE SPECIES APPLICATION SAMPLE IN Composite Samples (PPM— WHOLE Species ^^""cT" Composite APPLICATION s^„pj^^ IN Composite Samples (PPM — WHOLE TO Sampling (INCHES) BODY) to Sampling (INCHES) BODY) SAMPLING SITE E>— TOOGOODOO CREEK STATION 2— STONO RIVER —Continued Blue crab Background 1 7 — Second application (June 18, 1970) First application Blue crab 24 hrs 8 2.5-6 .010 (Oct. 14-15, 1969) 3 mos 2 5-5.5 .031 Blue crab 24 hrs 2 wks 4 wks 6 3 12 1-1.5 1-2 1-1.25 - 8 mos 12 1.25-4 — .STATION 3— UPPER ASHLEY RIVER, 6 wks 3 1 .5-3 .065 RUNNYMEADE PLANTATION 8 wks 12 1-1.75 .030 12 wks 2 5.5 .051 Blue crab Background 2 1.5 _ 14 wks 2 5.5 18 wks 3 1.5-5 First application 20 wks 3 3 - (Oct. 22, 1969) 22 wks 2 1 - Blue crab 24 hrs 3 2-3 .60 24 wks 6 2-3 26 wks 1 4 Second application 28 wks 4-5 _ (June 11, 1970) 30 wks 1 5 — Blue crab 24 hrs 1 .s .27 32 wks ' 3-6 STATION 4-COOPER RIVER, U.S. NAVAl, Second application AMMUNITION DEPOT (June .1-4. 1970) Blue crab 24 hrs 5 3-6 Blue crab Background 1 4 4 wks 6 wks 10 wks 4 6 1 3-4 4-6 4.5 .098 .015 First application (Oct. 17, 1969) 12 wks 12 1-2.5 — Second application 14 wks T 4-5 — (June 10. 1970) 18 wks 2 5-6 — Blue crab 24 hrs 4 6-8 .042 20 wks .3 2-5 ~ Mud crab 3 mos 1 8 mos 3 1 4.5 .25-.5 Third application (Oct. 27-28. 19701 STATION 5— LOWER ASHLEY RIVER OLD TOWN CREEK Blue crab 24 hrs. H 1.5-2.5 L/ 1 HV k 1 U L* 2 wks 4 2-5 — Blue crab Background 1 5.5 6 wks 5 1.5-4.5 — 8 wks 12 1-2 _ First application 10 wks 4 1.5-4.5 — (Oct. 22, 1969) 12 wks 5 1-5 — Blue crab 24 Ins 9 1 14 wks 3 1-2 — 3 mos 2 1-2.5 I6wk.s 12 1-2 20 wks 10 1.5-2.5 — Second application Mud crab 24 wks 12 .5-1.25 — (June 10, 1970) Blue crab 26 wks 2 2.5-3.5 — Blue crab 24 hrs 5 1.5-2.5 — 28 wks 12 1.75-3.5 — 3 mos 4 3-5 — 30 wks 2 2-3 — 8 mos 8 1-4 — 32 wks I 2.5 — STATION 6— WANDO RIVER. BERESFORD CREEK STATION 1 — RIVERLAND TERRACE POND (EAST) Blue crab Background 2 1.5-3 — Blue crab Background 3 1-2.5 — First application (Oct. 17. 1969) First application (Dec. 3, 19691 Blue crab 3 mos 2 5 — Blue crab 5 mos 8 .5-1.25 — Second application (June 8, 1970) Second application Blue crab 24 hrs 2 2-5 .025 (July 24, 1970) 3 mos 8 5-6 Blue crab 72 hrs 3 mos 15 13 .5-2 .75-1.5 .024 8 mos 12 1.25-3.25 — STATION 7— SOUTH SANTEE RIVER, ALLIGATOR CREEK Third application (Dec. 1. 1970) Blue crab Background 1 5.5 — Blue crab 48 hrs 12 .5-2 — Fiddler crab 48 hrs 4 .5-.75 First application Blue crab 2 wks 3 1-3 .026 (Sept. 18, 1969) 3 mos 12 1.5-4.5 — Blue crab 24 hrs 1 3 mos 2 4.5 1.5-3 — STATION 2— STONO RIVER. LOG BRIDGE CREEK Second application Blue crab Background 7 1.5-3 — (May 20, 1970) Blue crab 24 hrs 2 2-3 First application 3 mos 4 4-5 (Oct. 23, 1969) 8 mos 12 1-4 .012 18 Pesticides Monitoring Journal TABLE 7. — Mirex residues in fishes by sampling site and sampling lime, [ — = not detected] South Carolina, 1969-71 Species Interval FROM Mirex Application TO Sampling Number in Composite Sample Size of Individuals IN Composite Samples (INCHES) Mirex Residue (PPM — whole body) Species SAMPLING SITE A— TOOGOODOO CREEK Blackcheek tonguefish Background Southern kingfish Bnckground First application (Oct. 14-15. 1969) Silver perch 24 hrs 2 wks 4wks 8 wks Atlantic menhaden 16 wks 18 wks Spot 30 wks Second application (June 3-4, 1970) Spot 24 hrs 2 wks 4 wks 6 wks 8 wks 12 wks 14 wks 16 wks Third application (Oct. 27-28, 1970) Weakfish 24 hrs Silver perch 2 wks Striped mullet 6 wks 10 wks Silver perch 20 wks Atlantic menhaden 20 wks Bay anchovy 22 wks Silver perch 26 wks Spot 28 wks 30 wks 32 wks 2 2 II 10 10 13 12 7 12 5 5 6 12 6 12 4 12 12 12 3.5 3.5 4.5 3.5-4.5 3.5-4.5 4-5 3-4 3-4 3.5-5 4.5-5.5 3.5-4 3-4 2-3 4-5 3-5 4.5-7 4.5-5.5 7 7-9 4.5 4.25 2-3 5.5-7 1.5-3 2.25-3.25 2-3 .073 .028 .015 .060 .043 .017 SAMPLING SITE B— TOOGOODOO CREEK Silver perch Background First application (Oct. 14-15, 1969) Silver perch 24 hrs 2 wks 8 wks Spotted seatrout 8 wks Atlantic menhaden 14 wks 16 wks 18 wks Spot 28 wks Bluefish 30 wks Spot 32 wks Second application (June 3-4, 1970) Spot 24 hrs 2 wks 4 wks 6 wks 8 wks Striped mullet 8 wks Silver perch 10 wks Spot 12 wks Silver perch 14 wks Spot 16 wks Silver perch 18 wks 20 wks Third application (Oct. 27-28, 1970) Silver perch 24 hrs Spot 2 wks 10 4 3 1 12 6 12 12 I 2 6 12 7 4 4 I 3.5 3.5 4.5 4 7 2-4 3.5-4.5 4-5 2-2.5 7 3-4 3.5-4.5 3.5-5.5 3-4.5 3-4 3.5 4-5 4.5-6 3.5-4 4-5 3-4.5 6-6.5 5 4-5 6 .039 .027 .016 Interval from Mirex Application TO Sampling Number in Composite Sample Size of Individuals in Composite Samples (INCHES) Mirex Residue (PPM — WHOLE body) SAMPLING SITE B— TOOGOODOO CREEK— Continued Striped mullet Spot Fourspot flounder Spot 6 wks 20 wks 22 wks 24 wks 28 wks 30 wks 32 wks 3 4 3 2 12 5 11 5.5-6.5 6.5-7.5 2.5 3-4 1.5-2.75 3-4.5 2.5-4.25 .018 SAMPLING SITE C— TOOGOODOO CREEK Blackcheek tonguefish Background First application (Oct. 14-15, 1969) Hogchoker Silver perch Blackcheek tonguefish Silver perch Atlantic menhaden Mixed fish Searobin Spotted hake Spot Second application (June 3-4, 1970) Spot Weakfish Spot Silver perch Spot Third application (Oct. 27-28, 19701 Silver perch Bay anchovy Spot 24 hrs 2 wks 4 wks 6 wks 14 wks 20 wks 22 wks 24 wks 26 wks 26 wks ,30 wks 32 wks 24 hrs 2 wks 4 wks 6 wks 8 wks 10 wks 12 wks 14 wks 16 wks 18 wks 24 hrs 2 wks 26 wks 28 wks 30 wks 32 wks 1 2 7 5 12 4 10 2 2 12 3 5 12 12 3 3 12 12 5 12 4 4 4-5 3-4 3.5-4.5 4 2-4 2.5-4 7 4 2-3 4-6 3.5-4.5 4-6 4.5 3-4 4-5 3.5-4.5 2.5-3.5 3-4 4 5-6.5 4.5 4 2-3 2.25-3.5 3-4.5 2.5-4.5 .017 .028 SAMPLING SITE D— TOOGOODOO CREEK Silver perch Atlantic menhaden .034 Blackcheek tonguefish Background 2 3 First application (Oct. 14-15, 1972) Blackcheek tonguefish 24 hrs 2 3.5 2 wks 2 4 4 wks 3 3-4 6 wks 10 3.5-4 8 wks 12 3-4 12 wks 2 4 14 wks 10 3-5 15 wks 10 3.5-4.5 18 wks 3 3.5-4 Mixed fish 20 wks 2 3-4.5 Silver perch 24 wks I 7 Spotted hake 24 wks 2 4 Weakfish 26 wks I 10.5 Spotted hake 26 wks I 8.5 Mixed fish 26 wks 3 2-4 Spotted hake 28 wks 3 6 Bluefish 30 wks 2 3-6 Spot 32 wks 7 3-6 Vol. 7, No. 1, June 1973 19 TABLE 7. — Mirex residues in fishes by sampling site and sampling time. South Carolina. 1969-71- t — = not detected] -Continued Species Interval FROM MiREX Application TO Sampling Size of Mirex Number in Individuals Residlte Composite IN Composite (PPM — Sample Samples WHOLE (INCHES) BODY) SAMPLING SITE D— TOOGOODOO CREEK— Continued Second application (June 3-4, 1970) Spot 24hrs 12 4.5-5.5 2 wks 8 3-5 4 wks 2 4 10 wks 2 3.5-5.5 Silver perch 12 wks 8 2.5-3.5 14 wks 7 4 16 wks 2 3.5-5 Blackcheek tonguefisli 18 wks 4 4-5 Third application (Oct. 27-28, 1970) Silver perch 2 wks 10 4-4.5 Winter flounder 8 wks 1 10.5 Spotted hake 18 wks 2 3-4.5 Spot 20 wks 1 4.5 Spotted hake 24 wks 7 3.5-6 Silver perch 26 wks 2 3-5 Spot 28 wks 12 2-3 30 wks 2 3-3.5 32 wks 12 3-4.5 .046 Species Interval FROM Mirex Application TO Sampling Number in Composite Sample Size of Individuals IN Composite Samples (inches) STATION 3— UPPER ASHLEY RIVER, RUNNYMEADE PLANTATION Mirex Residue (PPM — WHOLE body) Atlantic croaker Background 1 5 — Hog choker Background 3 3 - First application (Oct. 22, 1969) Hog choker 24hrs 4 1-2.5 — 2 mos 8 2-3 .053 White catfish 2mos 6 2-3 .35 3 mos 1 12.5 .086 Striped mullet 3 mos 1 8 - Second application (June 11, 1970) Spot 24hr5 8 3-5 .82 Silver perch 3 mo-i 3 4 .20 Hog choker 3 mos 8 2-2.5 .096 White catfish 8 mos 7 3.5-7 .19 STATION 1— RIVERLAND TERRACE POND (EAST) Mummichog White mullet Atlantic silverside First application (Dec. 3, 1969) Atlantic silverside Mummichog Atlantic silverside White mullet Second application (July 24, 1970) Silver perch Sailfin molly Atlantic silverside Third application (Dec. 1, 1970) Sailfin molly White mullet Mummichog Atlanlic silverside White mullet Background Background Background 48 hrs 12 days 12 days 5 mos 72 hrs 3 mos 4 mos. 48 hrs 2 wks 2 wks 2 wks 6 wks 6 wks 3 mos 30 55 13 49 23 12 17 27 18 25 20 II 25 12 42 1-2 4-5 1.5-2.5 1.5-2 1-2.5 1.5-2 1.25-1.5 2-2.5 .5-1 2-3 1-1.5 .75-1 1.25-2.25 1 .75-2 1.5-2.5 2.5-3.75 1 STATION 4— COOPER RIVER, U.S. NAVAL AMMUNmON DEPOT STATION 2— STONO RIVER, LOG BRIDGE CREEK Blackcheek tonguefish Background Black drum Background Spotted seatrout Background First application (Oct. 23, 1969) Silver perch Second application (June IS, 1970) Spot Silver perch Spot 24 hrs 24 hrs 3 mos 8 mos 12 12 21 3-4 2.5-3.5 4-5 1.5-2,5 .054 Spot Background 3 2 — First application (Oct. 17, 1969) Silver perch 24 hrs 2 3.5 .21 Mixed fish 2 mos 2 4-6 — White catfish 3 mos 1 13 .036 Second application (June 10, 1970) Spot 24 hrs 9 2-3.5 .12 Hogchoker 24 hrs 6 1.5-2 — Silver perch 3 mos 5 5-5.5 .14 White catfish 8 mos 1 5.5 .045 Spot 8 mos 2 4.5-5.5 — Bay anchovy 8 mos 14 1.5-2.25 — STATION 5- -LOWER ASHLEY RIVER, OLD TOWN CREEK Spot Background 3 3.5 _ Winter flounder Background 1 8 — First applicalion (Oct. 22. 1969) Blackcheek tonguefish 24 hrs Atlantic menhaden 3 mos ,1 12 20 Second application (June 10. 1970) Spot 24 hrs R Silver perch 3 mos 9 Atlantic menhaden K mos 5 Striped mullet 8 mos 2 Star drum 8 mos 43 Pes TICIDES 2-3 4-4.5 4.5 5.5 1-1.75 Monitoring Journal TABLE 7. — Mire.x residues in fishes hy sampling site and sampling rime. South Cainlina. 1969-71 — Continued [ — = not detected! Interval FROM MlREX Application TO Sampling Size of Mirex Number in Individuals Residue Composite in Composite (ppm — Sample Samples whole (inches) BODY) STATION 6— WANDO RIVER, BERESFORD CREEK Silver perch Background 2 4.5 First application (Oct. 17. 1969) Pinfish 24hrs 1 7 Second application (June 8, 1970) Spot 24hrs 12 2.5-3.5 3 mos 12 3.5-5 Silver perch 8 mos 22 1.5-2 Species Interval FROM Mirex Application TO Sampling Number in Size of Individuals Composite in Composite Sample Samples (inches) Mirex Residue (PPM — whole body) STATION 7— SOUTH SANTEE RIVER, ALLIGATOR CREEK Atlantic croaker Hog choker Spot First application (Sept. 18, 1969) Spot Shcepshcad Second application (May 20, 1970) Spot Silver perch Spot Background Background Background 24 hrs 3 mos 24 hrs 24 hrs 3 mos 8 mos 6 12 4 2-2.5 2-3 2-3 8.5 6 5 3.5-6.5 3.75-4.5 .Oil TABLH 8. — Mire.x residues in miscellaneous organisms hy sampling site ami i^ampliiig time. South Carolina. l9f\9-7] [ — — not detected] Species Interval FROM Mirex Application TO Sampling Size of Number in Individuals Mirex Composite in Composite Residue Sample Samples (ppm) ' (INCHES) SAMPLING SITE A— TOOGOODOO CREEK Second application (June 3-4, 1970) American oyster I2wks 2-4 SAMPLING SITE B— TOOGOODOO CREEK First application (Oct. 14-15. 1969) Brief squid Second application (June 3-4. 1970) American oyster Third application (Oct. 27-28, 1970) American oyster 32 wks 12 wks 6 wks 28 2-4 10 wks 18 2-4 12 wks 10 2-4 SAMPLING SITE C— TOOGOODOO CREEK First application (Oct. 14-15, 1969) American oyster 32 wks 25 2-4 Southern periwinkle 32 wks 40 .5-.75 Phytoplankton (dry weight) 32 wks Second application (June 3-4, 1970) American oyster 12 wks Third application (Oct. 27-28. 1970) American oyster 6 wks 22 2-4 10 wks 13 2-4 12 wks 12 2-4 Nudibranch 16 wks 18 .5-1 Residues are whole-body basis unless otherwise indicated. Vol. 7, No. 1, June 197.^ Interval FROM Mirex Application TO Sampling Number in Composite Sample Size of Individuals IN Composite Samples (inches) Mirex Residue (PPM) ' SAMPLiNG SITE E>— TOOGOODOO CREEK Second application (June 3-4, 1970) American oyster 12 wks STATION 1— RIVERLAND TERRACE POND (EAST) First application (Dec. 3. 1969) Egg masses from 186 gravid grass shrimp 5 mos — Third application (Dec. 1, 1970) Dead white mullet 2 wks I 5 — STATION 5— LOWER ASHLEY RIVER, OLD TOWN CREEK Second application (June 10. 1970) Dead striped mullet 24 hrs I 11.5 — STATION 7— SOUTH SANTEE RIVER, ALLIGATOR CREEK First application (Oct, 18, 1969) Pied-billed grebe (breast muscle) (drowned in net) 3 mos 21 TABLE 9. — Mirex residues in birds by sampling site and sampling time, Soii/h Carolina. 1969-71 [ — — not detected] Quarterly Collection Species Mirex Residue (PPM) 1 Quarterly Collection Species SAMPLING SITES A-B-C— TOOGOODOO CREEK December 1969 March 1970 May 1970 September 1970 December 1970 February 1971 May 1971 Green Heron .99 Kingiisher 1.30 Clapper Rail .29 do. 1.40 do. .05 do. .10 do. .15 do. 1.90 do. .29 Oil glands from 5 Clapper Rails .52 Clapper Rail do. .06 do. .05 do. .08 do. .10 do. .06 Oil glands from 6 Clapper Rails .29 Green Heron .09 do. .17 do. — do. .07 Yellow Crowned Night Heron .11 Little Blue Heron — Clapper Rail .11 Clapper Rail do. .17 do. do. .02 do. — do. — do. .02 do. .05 do. .63 do. .02 do. .19 do. .04 do. — Clapper Rail .15 do. — 10 Rails (Muscle) .07 10 Rails (Fat) 1.20 Willet — Kingfisher .15 Clapper Rail .04 do. .13 do. .10 do. .03 do. .19 do. .04 do. .03 do. .07 do. .05 do. .75 do. _ Oil glands from 6 Clapper Rails .58 Louisiana Heron .11 Clapper Rail .01 Louisiana Heron .94 do. .14 Little Blue Heron .01 do. ,22 American Egrel 5.40 do. .05 SAMPLING SITE D— TOOGOODOO CREEK December 1969 March 1970 - Attempts to collect birds unsuccessful Clapper Rail do. Mirex Residue (PPM) 1 SAMPLING SITE D— TOOGOODOO CREEK— Continued May 1970 September 1970 December 1970 February 1971 May 1971 Plover Clapper Rail do. Kingfisher do. do. Clapper Rail do. do. Clapper Rail do. do. Clapper Rail Kingfisher Snowy Egret Green Heron Louisiana Heron do. .61 1.50 .04 .06 .03 .03 .17 .04 .03 STATION 2— STONO RIVER. LOG BRIDGE CREEK September 1969 December 1969 March 1970 May 1970 September 1970 December 1970 February 1971 May 1971 American Egret Little Blue Heron Clapper Rail Clapper Rail do. Clapper Rail do. do. Sora Rail Clapper Rail do. Clapper Rail do. do. Clapper Rail do. Clapper Rail do. Clapper Rail Little Blue Heron .12 .19 .55 .90 .18 .11 .08 .05 .10 .21 .16 .11 .06 .09 .13 .09 .70 STATION 3— UPPER ASHLEY RIVER, RUNNYMEADE PLANTATION September 1969 December 1959 March 1970 May 1970 September 1970 December 1970 Green Heron do. do. Snowy Egret American Bittern Snipe do. Anhinga (Juvenile) Anhinga Kingiisher (internal organs) Pied-Billed Grebe Anhinga Snipe do. do. do. .25 .15 .13 .69 1.80 .11 1.10 1.70 17.00 8.30 .28 .35 .05 .34 .25 .59 22 Pesticides Monitoring Journal TABLE 9. — Mirex residues in birds by sampling site and sampling lime, South Carolina, 1969-71 — Continued [ — = not detected] Quarterly Collection Species Mirex Residue (PPM) 1 STATION 3— UPPER ASHLEY RIVER— Continued February 1971 May 1971 Snowy Egret Marsh Hawk Least Bittern Louisiana Heron .60 1.50 2.20 1.10 STATION 4— COOPER RIVER, U.S. NAVAL AMMUNITION DEPOT September 1969 December 1969 March 1970 May 1970 September 1970 December 1970 February 1971 May 1971 Louisiana Heron — do. — Attempts to collect birds unsuccessful Snipe do. Grebe Louisiana Heron Green Heron Clapper Rail do. Clapper Rail American Bittern Grebe Least Bittern Clapper Rail .14 .89 .38 1.00 .60 .94 .19 .04 1.10 2.80 .18 STATION 5— LOWER ASHLEY RIVER, OLD TOWN CREEK September 1969 December 1969 March 1970 May 1970 September 1970 December 1970 February 1971 Louisiana Heron American Egret Clapper Rail do. Clapper Rail do. Sora Rail Virginia Rail Clapper Rail do. Eggs Clapper Rail do. Clapper Rail do. Clapper Rail Sora Rail .11 .35 .09 .07 .09 .06 .08 .07 ,06 .09 .01 Collection Quarterly Species Mirex Residue Mirex STATION 5— LOWER ASHLEY RIVER— Continued May 1971 Clapper Rail do. do. Eggs .10 .04 .05 STATION 6— WANDO RIVER, BERESFORD CREEK September 1969 December 1969 March 1970 May 1970 September 1970 December 1970 February 1971 May 1971 Snowy Egret American Egret .89 Attempts to collect birds unsuccessful... .05 Clapper Rail Snipe Clapper Rail White Ibis Kingfisher do. Sora Rail Clapper Rail do. Clapper Rail do. Clapper Rail do. Green Heron Little Blue Heron .47 .29 .04 .82 .25 .71 .07 .14 .17 STATION 7— SOUTH SANTEE RIVER, ALLIGATOR CREEK .September 1969 December 1969 March 1970 May 1970 September 1970 December 1970 February 1971 May 1971 Snowy Egret Little Blue Heron Clapper Rail do. Snowy Egret do. Kingfisher do. Snowy Egret American Egret Snowy Egret Louisiana Heron Clapper Rail Snowy Egret .20 .06 .51 .45 .13 .17 .10 .11 Residues are breast and upper wing muscle unless otherwise indicated. Vol. 7, No. 1, June 1973 23 TABLE 10. — Average mirex residues in muscle tissue of herons and egrets at each station, South Carolina, 1969-71 TABLE 11. — Average mirex residues in muscle tissue of clapper rails at each station. South Carolina, 1969-71 AVERAfiF. RFsmiTFS IN PPM ( ) Average Residues IN PPM AND Number of Birds ( ) Station Sept. Dec. Mar May 1970 Sept. 1970 Dec Feb May 1971 Station Sept. 1969 Dec. 1969 Mar. 1970 May 1970 Sept. 1970 Dec. 1970 Feb. 1971 May 1971 1969 1969 1970 1970 1971 A-B-C .60 .07 .11 .09 .07 .14 .01 A-B-C .99 (I) .07 (6) .11 (1) 1.13 (6) D (7) (6) .06 (1) .31 (13) .00 (12) .04 (11) .06 (1) D .06 (4) (2) (2) (3) (3) (1) 2 .06 (2) .70 (1) 2 .19 .73 .10 .07 .16 .08 .11 .09 (1) (2) (3) (2) (3) (2) (2) (1) 3 .18 (3) .69 (1) .60 (1) 1.10 (1) 3 4 .77 .19 .18 4 .00 (2) .69 (2) 5 .23 .08 .00 .02 (2) .06 (1) .09 (1) .05 5 .00 (2) (2) (2) (2) (2) (2) (1) (3) 6 .45 (2) .16 (2) 6 .05 (1) .47 (1) .02 (2) .54 (2) .39 (2) 7 .00 (2) .10 (2) .48 (2) .15 (2) .11 (1) 7 Overall .00 (2) .10 (I) Overall average ,12 .84 .08 .69 .48 .25 .61 average .19 .47 .07 .16 .07 .23 .15 .07 Total Total birds (13) (2) (8) (2) (2) (4) (15) birds (1) (13) (14) (8) (23) (23) (18) (7) TABLE 12. — Mirex residues in nnunnials by sampling site and sampling lime. South Carolina. 1969-71 [ — = not detected] Quarterly Collection Mirex Residue (PPM) > SAMPLING SITE A— TOOGOODOO CREEK December 1969 March 1970 May 1970 September 1970 December 1970 February 1971 May 1971 Raccoon Fat Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon .14 .97 .05 1.30 .20 .02 .26 .02 .16 .88 SAMPLING SITE B— TOOGOODOO CREEK December 1969 March 1970 May 1970 Raccoon Fat Raccoon Fat Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon .16 .07 .43 .03 .66 .12 Quarterly Collection Species Mirex Residue (PPM) > SAMPLING SITE B— TOOGOODOO CREEK— Continued September 1970 December 1970 February 1971 May 1971 Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon .21 .04 .12 .16 .04 SAMPLING SITE C— TOOGOODOO CREEK December 1960 March 1970 May 1970 September 1970 December 1970 February 1971 May 1971 Raccoon — Raccoon — . Attempts to collect raccoons unsuccessfuL Attempts to collect raccoons unsuccessful^ Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon .15 .24 .02 .08 .04 .09 .09 .02 24 Pesticides Monitoring Journal TABLE 12. — Mirex residues in mammals by sampling sile and scimplini; rime, South Carolina. 1969-71 — Continued [ — = not detected] quartierly Collection Species Mirex Residue (PPM) ' SAMPLING SITE D— TOOGOODOO CREEK December 1969 March 1970 May 1970 September 1970 December 1970 February 1971 May 1971 Raccoon — Raccoon — Fat — ^Attempts to collect raccoons unsuccessful- Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon .01 .04 .01 .04 STATION 2— STONO RIVER, LOG BRIDGE CREEK December 1969 Raccoon Fat Raccoon Fat March 1970 Raccoon May 1970 Raccoon Raccoon September 1970 Raccoon Raccoon December 1970 Raccoon Raccoon February 1971 Raccoon Raccoon May 1971 Raccoon 1.40 .07 .07 1.90 .20 .04 STATION 3— UPPER ASHLEY RIVER, RUNNYMEADE PLANTATION December 1969 March 1970 May 1970 September 1970 December 1970 February 1971 May 1971 -Attempts to collect raccoons unsuccessful-. -Attempts to collect raccoons unsuccessful Raccoon — Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Opossum ,56 .12 .88 .10 .19 1.90 .09 3.30 STATION 4— COOPER RIVER, U.S. NAVAL AMMUNITION DEPOT December 1969 March 1970 May 1970 Raccoon Raccoon Raccoon Raccoon Raccoon .80 .39 .60 4.40 .28 ^ Residues for thigh muscles unless otherwise indicated. Vol. 7, No. 1, June 1973 Quarterly Collection Species Mirex Residue (PPM) > STATION 4— COOPER RIVER— Continued September 1970 December 1970 February 1971 May 1971 Raccoon Raccoon .90 1.30 -Attempts to collect raccoons unsuccessful- -Attempts to collect raccoons unsuccessful- Attempts to collect raccoons unsuccessful-. . STATION 5— LOWER ASHLEY RIVER, OLD TOWN CREEK December 1969 March 1970 May 1970 September 1970 December 1970 February 1971 May 1971 Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon .06 .03 .02 .05 STATION 6— WANDO RIVER, BERESFORD CREEK December 1969 March 1970 May 1970 September 1970 December 1970 February 1971 May 1971 Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Raccoon Opossum Opossum .04 .16 .02 .02 .04 2.20 STATION 7— SOUTH SANTEE RIVER, ALLIGATOR CREEK September 1969 December 1969 March 1970 May 1970 September 1970 December 1970 February 1971 May 1971 Raccoon — Raccoon — Raccoon — Raccoon — Raccoon — .Attempts to collect raccoons unsuccessful ..Attempts to collect raccoons unsuccessful-.. Raccoon — Raccoon — Raccoon Raccoon Raccoon .06 .03 25 TABLE 13. — Average mirex residues in iiiiiscle tissue of raccoons at each station. South Carolina, 1969-71 TABLE 14. — Summary of birds and mammals containing mirex residues in excess of 1.0 ppm, South Carolina, 1969-71 Average Residues in PPM AND Number of Raccoons ( ) Station Animal Species MiKEX Residues IN PPM Month of Station Sept. Dec. Mar. May Sept. Dec. Feb. May Sample Collection 1969 1969 1970 1970 1970 1970 1971 1971 BIRDS A .14 .05 .75 .14 .01 .08 .44 (1) (1) (2) (2) (2) (2) (2) A-B-C A-B-C Kingfisher Clapper Rail 1.30 1.40 December 1969 December 1969 B .00 .25 .20 .11 .00 .08 .10 (2) (2) (4) (2) (2) (2) (2) A-B-C A-B-C Clapper Rail American Egret 1.90 5.40 December 1969 May 1971 c .00 .20 .05 .07 .06 (2) (2) (2) (2) (2) D 3 Kingfisher American Bittern 1.50 1.80 September 1970 December 1969 D .00 (2) .03 (2) .01 (2) .00 (2) .02 (2) .00 (2) 3 3 Snipe Anhinga 1.10 1.70 March 1970 May 1970 2 .00 .00 .74 .99 .00 .12 .00 3 Kingfisher 17.00 May 1970 (2) (1) (2) (2) (2) (2) (2) 3 Marsh Hawk 1.50 February 1971 3 .00 .52 .05 .19 1.00 3 Least Bittern 2.20 May 1971 (1) (3) (2) (1) (2) 3 Louisiana Heron 1.10 May 1971 4 .60 2.50 .28 1.10 4 Louisiana Heron 1.00 September 1970 (2) (2) (1) (2) 4 Grebe 1.10 February 1971 5 .00 .00 (2) .00 (2) .03 (2) .03 (2) .00 (2) .03 (2) 4 Least Bittern 2.80 May 1971 (2) .02 .00 .08 .00 .02 .02 .20 MAMMALS 6 (2) (2) (2) (1) (2) (2) (1) A 2 Raccoon Raccoon 1.30 1.40 May 1970 May 1970 7 .00 (1) .00 (2) .00 (2) .00 (2) .03 (2) .03 (1) 2 3 3 Raccoon Raccoon Opossum 1.90 1.90 3.30 September 1970 May 1971 Overall May 1971 average .00 .08 .46 .27 ,37 .02 .06 .22 4 Raccoon 4.40 March 1970 Total 4 Raccoon 1.30 September 1970 raccoons (1) (17) (12) (16) (18) (18) (17) (15) 6 Opossum 2.20 May 1971 26 Pesticides Monitoring Journal Eggshell Thinning, Chlorinated Hydrocarbons, and Mercury in Inland Aquatic Bird Eggs, 1969 and 1970 ' Raymond A. Faber and Joseph J. Hickey ABSTRACT In the Upper Great Lakes Stales. 9 out of 13 species of fish- eating birds were found in 1969-70 to liave sustained statis- tically significant decreases in eggslicll thickness since 1946. Maximum changes in a thickness index occurred in great bhte herons ( — 25Vc>. red-breasted mergansers ( — 23%). common mergansers (—15% I and double-crested cormo- rants (—15%). Heron eggs taken in Louisiana generally dis- played a smaller post-'46 change ihcin herons in the Middle West. On a lipid basis, mean PCB- and DDE-residue levels exceeded 100 ppm in 7 out of 13 species in the Great Lakes States, and in 2 of 7 species in Louisiana, the average DDE: PCB ratios in the two regions being 1.25:1 and 3.9:1. re- spectively. Individual dieldrin values tended to be Itigher in Louisiana (31.6 and 13.95 ppm in heron species from two different locations), although values reached 1 0.1 and 9.4 ppm in great blue and black-crowned night herons in Wis- consin. BHC averaged 3.01 and 0.39 ppm in the Lake States and Louisiana, respectively. Of eggs examined for mercury. 29% had levels greater than 0.5 ppm. and 9'!< . greater than 1.0 ppm on a wet-weight basis. Mercury levels in a small sample of eggs from Louisiana were consistently low. The differences in mercury levels between the two regions thus were similar to those found for the chlorinated hydrocarbons. While DDE was a prominent factor for most groups, especi- ally herons, in relation to the eggshell thinning observed, dieldrin was also important to two groups e\en ihough DDL was present in much higher amounts. PCB's were also im- portant to mergansers, while mercury was posilivelv cor- related with thickness index in grebes and negatively cor- related in mergansers. iprom the Department of Wildlife Ecology, University of Wisconsin. Madison, Wis. 53706, under contract with the Bureau of Sport Fish- eries and Wildlife, U. S. Department of the Interior. Patuxent Wild- life Research Center, Laurel, Md. Vol. 7, No. 1, June 1973 I Introduction This report summarizes the levels of chlorinated hydro- carbons and mercury in 117 eggs of 19 species of aquatic-feeding birds collected in 1969 and 1970 in the Upper Great Lakes States (Wisconsin, Michigan, and Minnesota) and in Louisiana. Shell thickness and a thickness index (24) for these 1 17 eggs are compared to museum data for eggs collected before 1947. Of the 30 species of raptorial and fish-eating birds in which the eggshell-thinning phenomenon has now been found in great Britain [25) and North America (/). 6 species are known to have DDE associated with this phenomenon (2. 4. 7. 9. 13. 16. 32). Blus ci al. (4) used multiple regression to obtain a predictive equation for shell thick- ness of brown pelican eggs iPclecuniis occidenialis) in which DDF was the most important factor. Laboratory confirmation of this DDE effect has been provided by Heath et al. (14). Bitman et al. (3). and Wiemeyer and Porter (33). The effect of dieldrin on eggshell thinning has also been reported by Lchner and Egbert (22) and Enderson and Berger (9). Because of the combined presence of the chlorinated hydrocarbons in animal tissues, partial-correlation analysis (2H. 29) was used in this study to determine the importance of each chemical, including mercury, to eggshell-thickness changes in the 6 families and 19 species in our samples. Chemical rcsitlues in birds' eggs, of course, only reflect levels in the females that laid the eggs and are not necessarily the cause of shell-thinning. 27 Methods FIELD COLLECTIONS All eggs were collected in 1970 except for those of the redbreasted merganser which were collected in 1969. Sites for collection within the Great Lakes area and Louisiana were selected largely on the basis of availa- bility rather than with regard to probably "polluted" areas, except in the case of the herring gull. Herring gull eggs came from upper Green Bay, Wis., where eggs in previous years have had high levels of DDE (20). Only one viable egg was collected from each active nest, but all eggs were collected from nests con- taining only addled or abandoned eggs. All eggs were wrapped in aluminum foil and frozen until analysis. EGGSHELL MEASUREMENTS Eggshell measurements of pre- 1947 eggs were taken from specimens in the collections of five museums and one private collector. All eggshells were measured fol- lowing the methods of Hickey and Anderson {16). In order to increase sample size, we first compared pre- 1947 data from different regions; if no significant dif- ferences were found, we combined the samples to form a larger one for comparison with the 1970 data. TTiese data are presented in Table 1 . For some species, a few eggs collected after 1946 (usually 195S or after) were found in these collections. In these cases, comparisons were made in two ways, i.e.. pre-1947 with 1970 and pre-1947 with 1970 and the post-1946 museum eggs combined. In addition to shell thickness, we relied on a statistic — thickness index — initially used by Ratcliffe (24) and calculated as shell weight divided by the product of egg length times breadth. The thickness index was used to measure eggshell changes for two reasons: (1) it seems to be less subject to variation in the measuring technique when many species with very different eggshell char- TABLE 1. — Comparison of pre-1947 eggshell thickness and thicl^ness index with 1970 data and wilh 1970 and posl-1946 museum egg data combined Collection Region Mean Thickness in «M It 95% Confidence Level Mean Thickness Index it 95% Confidence L-evei. Common and Scientific Name (N) Pre-1947 (N) 1970'/ (N) 1970 AND Posl-1946 Museum Egg Data Combined Percent Change (N) Pre-1947 (N) 19701/ {Nt /970 and Post-1946 Museum Egg Data Combined Percent Change Red-necked grebe (Podiceps griscsena) Wisconsin fVisconsin and Ontario (112) 0.357 ± .005 (2) 0.350 ± .00 (6) 0.338 ±. .015 - 2.0 — 5.3 (112) 1.84 ± .02 (3) 1. 62 ±.21 (7) 1.68 ± .10 - 13.0* — 8.7*' Pied-billed grebe (Podilymbus podiceps) Wisconsin Wisconsin (71) n.286± .005 (9) 0.288 ± .021 + 0.7 (71) 1.47 It .02 (9) 1.45 ± .12 (17) 1.42 ^ .06 — 1.4 - 3.4 White pelican (Pelecanus crythrorhynco^) Minnesota - (92) 0.683 ± .010 (10) 0.633 ± .040 - 7.3» -'(94) 3.33 ± .05 (10) 3.12± .22 - 6.3 Double-crested cormorant iPhalacrocorax auritusi Minnesota -' (350) 0.430 ± ,003 (19) 0.370 ± .014 - 14.0* - (370) 2.12 It .02 (19) 1.80 ± .08 - 15. 1* Great blue heron (Ardea herodias) Wisconsin ■■(170) 0.393 ± .004 (5) 0.330 It .029 - 16.0* - (288) 2.05 i .02 (5) 1.54± .18 - 24.9«' Common egret (Casmerodius albus) Wisconsin (235) 0.295 ± .003 (4) 0.275 ± .062 - 6.8 (235) 1.49 i .01 (4) 1.38 ± .34 - 7.4* Black-crowned night heron 1 Nycticora.x nyticorax) Wisconsin - (134) 0.287 rt .003 (6) 0.272 ± .023 - 5.2 ■ (1581 1.44 It .02 (6) 1.30 ±.14 - 9.7 American bittern (Botaunts lentigirwsu-i) Wisconsin (68) 0.243 i: .004 (1) 0.24 0 (72) 1.22 ± .02 (1 ) 1.18 - 3.3 Hooded merganser (Lophodyle^ ciicidlalii^) Wisconsin (44 1 0.614 i .019 (11) 0.599 It .035 - 2.4 (44) 4.00± .11 (11) 3.82 ± .24 - 4.5 Common merganser (Mergus merganser) Wisconsm and Michigan (45) 0.437 ± .014 (13) 0.368 It .012 - 15.8'« (62) 2.49 ± .06 (13) 2.11 ± .08 - 15.3' 28 Pesticides Monitoring Journal acteristics are considered: and (2) there seems to be a change in density of the shell in very thin-shelled eggs in some species (10). CHEMICAL ANALYSIS All eggs were analyzed for chlorinated hydrocarbons by WARF Institute, Inc.. Madison, Wis., using gas chro- matography. Methods of analysis followed those given by Anderson el al. i2) with the exception described here. A Barber-Coleman Pesticide Analyzer Model 5360 with two columns was used: one column was packed with 5% DC-200 on 60/70-mesh Chromport XXX, with a column temperature of 200°C and a nitrogen flow rate such that p.p'-DDT had a retention time of 6-8 minutes. The other column was packed with 3% OV-17 on 100/120-mesh Gas Chrom Q, with a column tempera- ture of 195' C, and a flow rate such that lindane had a retention time of I minute. The estimated polychlori- nated biphenyl (PCB) values were determined from the heights of the peak between TDE and DDT and from the peak at DDT after saponification. Recovery rates were 80-90%. The 86 eggs analyzed for mercury included all eggs from the Great Lakes area (one herring gull sample was lost) and 1 egg per species, chosen randomly, from the 7 species of herons from Louisiana. Five black tern eggs were analyzed by the Gulf Radiation Technology Division, Gulf Energy and Environmental Systems. Inc., using neutron-activation analysis, the samples analyzed being mostly albumen mixed with a small amount of yolk. Weighed portions of each sample were sealed in vials and irradiated at a flux of 10'- thermal neutrons per cm- per second together with a mercury comparator standard. The irradiated samples were digested, in the presence of mercury carrier, in a mixture of HNO-, and TABLE I. — Comparison of prc-1947 Ciit^sheU thickness and lliickness index witli 1970 ilata and willt 1970 and posl-1946 niKseiini egg data combined — Continued Collection Region Mean Thickness in MM ± 95% Confidence Level Mean Thickness Index ± 95% Confidence Level Common and Scientific Name (Nl Pre- 1947 (N) 1970V (N) 1970 and Posl-1946 Museum Efif; Data Combined Percent Change (N) Prf-1947 (N) 19701/ IN) 1970 AND Posl-1946 Museum F.i.;^ Data Combined Percent Chance Red-breasted merganser {Meraits serrator) Wisconsin (141) 0.365 ± .003 (11) 0.303 ± .013 - 17.0" (148) 2.01 ± .02 (11) 1.55 ±.08 22 9** Herring gull (Larus argenlalus) Wisconsin = (3691 0.375 ± .002 (10) 0.328 ± .021 - 12.5* = (456) 1.73 ±0.01 (10) 1.49 ± .10 - 13.9' Black tern iChlidonias nigra) Wisconsin (91 ) 0.155 ± .002 (5) 0.132 ±.022 - 14. 8** (91) 0.69 ± .01 (5) 0.62 ±.08 - lO.l" Green heron iBiitorides virescens) Louisiana Louisiana and South Carolina (100) 0.176 ±.002 (3) 0.163 ±.038 (//) 0.166 ±.008 - 7.4 — .'>.7« (105) 0.89 ± .01 (3) 0.81 ±.31 (//) 0.8.1 ±.05 - 9.0* - 6.7" Little blue heron (Florida caerulea) Louisiana (18) 0.239 ± .007 (5) 0.222 ±.030 - 7.1 (18) 1.14 ± .04 (5) 1.09 ± .10 — 4.4 Cattle egret (Bubulcus ibh) Louisiana Louisiana and South Carolina (7) 0,236 ± .007 (5) 0.228 ± .010 (20) 0.228 ±.007 - 3.4 - .<.4 (7) I.I0± .05 (5) 1.06 ± .06 (20) 1.07±0..1 - 3.6 - 2.7 Common egret (Casmerodiu.s alhus) Ixiuisiana ( 235 ) 0.295 ± .003 (5) 0.292 ±.013 - 1.0 (235) 1.49± .01 (5) 1.44 ± .08 - 3.4 Snowy egret (Leitcophoyx llnila) Louisiana Louisiana and South Carolina (85) 0.235 ±.004 (5) 0.222 ±0.27 (9) 0.220 ± .014 - 5.5 - 6.4' (85) 1.14 ± .02 (5) 1.08± .11 (9) 1. 07 ±.06 - 5.3 - 6.1' Louisiana heron (Hydranassa tricolor} Louisiana (8) 0.240 ±.013 (5) 0.236 ±.030 - 1.7 (8) I.I9± .05 (5) I.I4 ± .14 - 4.2 Yellow-crowned night heron tNyctanassa \iolacca} Louisiana (71 ) 0.287 ± .004 (5) 0.282 ± .027 - 1.7 (71 ) 1.45 ± .02 (5) 1.44 ± .16 - 0.7 ' Red-breasted merganser collected in 1969. = Pre-1974 data from Anderson and Hickey (7). Vol. 7, No. 1, June 1973 • Significant diflffference (P<0.00.) by Student's t-test. " Highly significantly different (P<0.005) I 29 H0SO4 under reflux conditions. Radiochemical pro- cedures were used to isolate mercury as the metal. Mul- tichannel gamma-ray spectrometry was used to identify and quantitate mercury. The remaining eggs were an- alyzed for mercury by WARF, Inc.. using the method in The Analyst (19), modified by atomic absorption spectrophotometry with cold vapor. These two methods measure total mercury, both organic and inorganic. Because of the biological methylation of mercury (18. 21). and the biological route that mercury takes in reaching eggs, we feel it is safe to assume that most of the mercun,' was in the methylated form. Neither of the two methods gives consistently higher results than the other, but both apparently are not extremely precise (R. F. Christensen, personal communication). However, both methods give high rates of recovery of standards (approximately 9Kf for atomic absorption and 96% for neutron activation). Results and Discussion EGGSHELL CHANGES The major post-1946 eggshell changes encountered in this study involved great blue herons (—25%). red- breasted mergansers (—23'^). common mergansers (—15%), and double-crested cormorants (— 159f ) in that order, all of these specimens collected in 1969 or 1970 from the Great Lakes States (Table 1). In this region. 9 of 13 species exhibited a statisticallx significant (P<0.05) change in shell thickness or thickness index. However, for those species in which addled eggs were included, the sample is biased because these eggs have been incubated and the thinnest eggs would have been broken (11). The heron eggs taken farther south displayed a generally smaller post-1946 eggshell change. While this change was statistically significant in 2 out of 7 species, eggs of the 7 southern species shown in Table I involved a mean (unweighted for sample size) change in thickness index amounting to —4%. whereas eggs of the four herons in the Great Lakes States showed a mean change of — 1 1 %. In eggs of the common egret, the only species for which we had samples from both Louisiana and the Great Lakes States, the thickness index change in Wisconsin was —7% (P<0.05) and in Louisiana. -3% (not significant). Eggs of each of the 19 species studied had a negative change in mean thickness index, although many of these changes were not statistically significant. Mean changes in measured thickness were negative in all but the pied-billed grebe. The mean thickness of one museum clutch of post-1946 Louisiana heron eggs from Texas was significantly greater than the pre- 1947 mean. Changes in three museum clutches of Louisiana heron eggs from Mexico were —13% (P<0.005) in thickness and —12% (P<0.005) in thickness index. The proba- bility of negative changes in the 19 thickness-index estimates due to chance alone is infinitesimal (P< 19 X 10~'^) and for negative changes in 18 of the 19 thick- ness estimates is very small (P< 36 X 10~') (R. G. Heath, personal communication). The differences between percent decrease in thickness and thickness index for great blue herons (Table 1) illustrate the value of the index. Thin-shelled great blue heron eggs have very rough shells which are difficult to measure accurately with a thickness micrometer; ap- parently, these eggs are also less dense. The thickness index takes into account both this change and the actual thickness, and probably is better related to the decrease in breaking strength that accompanies eggshell thinning. In general, the consistent pattern of eggshell change in these species strongly suggests that, with larger post- 1946 samples, statistically significant decreases in shell thickness will be found in virtually all fish-eating species of birds in these latitudes of North America. We are uncertain about the biological significance of decreases in shell thickness below 10%. Certainly, widespread eggshell breakage does not occur with changes below this magnitude. Normal eggshells do exhibit wide varia- tion in thickness. Ernst Mayr (personal communication) feels that natural selection would produce an eggshell somewhat thicker than that normally needed to prevent breakage. Under normal conditions, the selection pres- sure against a genot>pe with too thin an eggshell is probably greater than that against a genotype which uses excess metabolic energy in producing a thick eggshell. RESIDUE LEVELS IN EGGS In Table 2, eggshell changes are compared with mean residues of organochlorines, PCB's, and mercury in the eggs. Means influenced by one high value are indicated by footnotes. Residues of DDE and PCB"s varied greatly, both among and within species. The herring gull eggs, collected by D. W. Anderson, from Sister Island in Green Bay had by far the highest levels of any species, while red-breasted merganser eggs collected 1 year earlier from the same island had almost 10 times less (Table 2). The levels of DDE and PCBs found in eggs from Louisiana were much lower than those in eggs from the Great Lakes States, with one exception, the green heron eggs from near Monroe. La. where DDT has been used extensively on cotton in the past (L.D. Newsom. personal com- munication). Eggs from Louisiana generally had less PCB's in relation to DDE than those from the Great Lakes States (see DDE: PCB ratios in Table 2). 30 Pesticides Monitoring Journal TABLE 2. — Eggshell thickness changes and mean residues of organochlorines, PCB's, and mercury by species U X Mean Residues in PPM z S Species of Collection z li £ 2 ppm. These were also the only species for which abandoned clutches, dump nests, or un- TABLE 3.. — Distribution of mercury residues in eggs Specie,s Ahea OF Collection Number OF Eggs Number of (PPM, Eggs per Residue Level wet-weight basis) OF Eggs <0.05 0.05- 0.24 0.25- 0.49 0.50- 0.99 >1.0 Red-necked grebe Rush Lake, Wis. ^ ,1 Pied-billed grebe Mud and Rush Lakes, Wis. 9 7 •) White pelican Milan. Minn, (western) 5 2 3 Double-crested cormorant Milan. Minn, (western) s 1 3 4 Great blue heron Horicon Marsh, Wis. 5 J 1 1 Common egret Horicon Marsh, Wis. 4 1 1 1 1 Black-crowned night heron Horicon Marsh, Wis. 6 .1 1 1 1 American bittern Ladysmith, Wis. 1 1 Hooded merganser Chippewa Co.. Wis. 6 2 2 2 Hooded merganser Price Co., Wis. ; 2 Common merganser Brule & Pine Rivers, Wis. T 1 I Common merganser .Seney, Mich. (U.P.) ■ II 8 2 1 Red-breasted merganser Sister Island, Green Bay, Wis. 3 3 Herring gull Sister Island, Green Bay. Wis 9 5 4 Black tern Oconto, Wis. (on Green Bay) 5 3 -y Seven species of herons and egrets Louisiana 7 7 TOTAL 86 1 30 30 17 8 ' Four of these were reported as >1.0 ppm. but had to be adjusted for desiccation. 32 Pesticides Monitoring Journal hatched eggs were found in the course of our searching for active nests. Of 16 nests located for the three species of mergansers, 1 1 were in one or another of these categories. However, some eggs with more than 1 .0 ppm came from active nests and were in an advanced in- cubation stage when taken. The addled red-breasted merganser eggs (Table 4) showed high mercury levels (1.1-1.9 ppm) and also high dieldrin levels (6.44-9.73 ppm, lipid basis.), while viable eggs collected from the same nests had much lower dieldrin levels (0.15-2.37 ppm). Viable eggs were not analyzed for mercury. The comparison of means of dieldrin did not show a signifi- cant difference. The sum of DDT and TDE was also higher in addled than in viable eggs. However, the combination of aldrin (the parent compound of dieldrin) and mercury is apparently more toxic to birds than is mercury alone (5, 6, 8). These data suggest a need for research into the relationship between dieldrin and other chemicals and embryonic mortality in this species. Some of our highest mercury values were from eggs collected in the Chequamegon National Forest and Nicolet National Forest in northern Wisconsin, and from the Seney National Wildlife Refuge in Michigan. Mer- cury values in eggs of herring gulls and black terns collected from Green Bay, Lake Michigan, were also somewhat higher than in most eggs from other areas. Eggs from other areas showed no consistent differences. except that levels in eggs from Louisiana were con- sistently low. CONTRIBUTIONS OF RESIDUES TO EGGSHELL THINNING Both DDE and dieldrm have been associated with eggshell thinning (2. 7. 22). However, as our data show, an egg with high levels of one type of chlorinated hydro- carbon will often have high amounts of the others as well. Therefore, spurious correlation is a possibility, and in our data, this was apparently the case. In simple correlation, all of the residues had significantly negative coefl(icients with percent of pre- 1 947 thickness index in one category or another when wc combined the data into family groups. We. therefore, used partial correla- tion {29) to segregate the spurious correlations and de- termine the residues which were significantly related to eggshell thinning. In order for the analysis to be valid, it was necessary to assume that the samples were col- lected in random fashion and that the transformed data were normally distributed. Our data essentially satisfied both requirements. Since the sample of herring gull eggs was not a random one and also because the distribution of residue values was very different from those of any of the other species, these data were excluded from all analyses of combined groups. All residue data were transformed to their logarithms for the correlations be- cause this gave a more normal distribution of residue values. Virtually all correlation coefficients were in- creased when the log transformation was used. Partial correlation coefficients between percent change in pre- 1947 thickness index and residues were calculated for all of the chemicals which were significantly correlated with percent thickness index in the simple correlations. Our data did not satisfy the theoretical requirements for multiple-regression analysis, but we did calculate the coefficient of determination, R-, to show the amount of variation in percent pre- 1947 thickness index which could be accounted for by the combined residues. The extent of correlation of a given residue type with the thickness index varied from family to family (Table 5). Sample sizes for most species were too small to permit meaningful intraspecific analyses by partial correlation. TABLE 4. — Rcxidiies and eggshell piiruinctcrs for ihrcc viable ( V ) and three addled (A ) eggs from the same nests of red-breasted mergansers Nest Type of Egg Residues in ppm » Percent Lipid Eggshell Thickness Eggshell Thickness Index DDE PCB's DlELDRTN DDT4-TDE BHC Mercury 1 2 3 V A V A V A 187 336 201 330 351 328 224 294 607 348 1,375 644 2.37 9.73 0.15 8.31 1.98 6.44 10.5 43.7 19.0 21.6 n 27.7 n.69 n.s5 0.90 0.60 1.37 5.06 ( = ) M (- ) 1.8 (•) 1.90 15.6 18.8 16.8 16.6 12.6 25.3 0.33 0.34 0.28 0.30 0.28 0.29 1.74 1.72 1.51 1.48 1.43 1.55 MEAN V A 246.0 297.6 735.6 428.7 -■1.50 ^'8.16 9.86 3i.n 0.99 2.17 1.6 15.0 20.2 0.30 0.31 1.56 1.58 1 Residues on lipid basis for organochlorines, on wet-weight basis for mercury. 2 Not analyzed for. " Means significantly different (P<0.01 ) when calculated on wet-weight basis. Vol. 7, No. 1, June 1973 33 TABLE 5. — Coefficients of determination (R-) and partial correlation coefficients for correlation of percent clianges in sheU-lhickncss index witi} the logaritlim of each residue Number OF Eggs R- DDE PCBs DlELDRlN DDT + TDE BHC Merclhiy Eggs in which mercury was measured: Heron eggs 23 543... — .448* -.224 -.196 + .333 - - Merganser eggs 24 .646* •* + .100 -.205 -.241 + .102 -.175 — .410 All eggs in Upper Great Lakes Stales (12 species) 69 .392* •• -170 -.019 -.222 + .032 — -.299* All addled eggs (7 species) 30 .204* — — — — — -.451» Aall viable eggs ( 16 species) 46 .505*** -.115 -.188 -.369* f.032 _ — Both viable and addled eggs (18 species) 76 ,367*** -.126 -.039 -.242* I-.040 - -.253* Eggs without mercury considered: Heron eggs 49 494... -.575*** -.199 1 .159 + .359* — Merganser eggs 29 .609*** t-.04R -.410* I .115 -062 -.199 All eggs in Upper Great lakes States (12 species) 74 .352* •' -.22.'i -.174 -.097 + .063 — AU viable eggs (16 species) 77 .470*** -.384*«* -.284* -.034 + .131 + .078 Both viable and addled eggs (18 species) 107 .378* •* -.335»*- -.251' -.003 + .122 + .157 ' P = <0.05. '•?= <0.01. *»•? = <0.005. It appears, however, that there may be very important differences between families in the effect of a given compound on eggshell thinning. For the herons, DDE was the only compound which was significantly cor- related with percent of pre- 1947 thickness index. DDT + TDE showed a significantly positive correlation with percent of pre- 1947 thickness index in the herons; how- ever, this may be an artifact of the number of correla- tions performed, a statistically significant relationship occurring by chance alone. Previous field studies have failed to show that DDT or TDE was a significant factor in eggshell thinning; Jefferies (!7) reported that DDT apparently increased eggshell weight in Bengalese finches, but this increase was very small (less than 1%) and probably not significant. For mergansers, PCB was the only compound among DDE, PCB. dieldrin, DDT + TDE, and BHC which was significantly correlated with percent of pre- 1947 thickness index. Although the sample size was small (N=ll). the six residue types together accounted for 97.69^ (P < 0.005) of the vari- ation in percent thickness index in the grebes. However, none of the individual residues was significantly corre- lated with percent of pre- 1947 thickness index in simple correlation, and so we did not calculate partial correla- tion coefficients. For the other families and individual species, sample sizes were small, and the coefficient of determination did not show a significant reduction in variance of the percent thickness index. There are several theories concerning the physio- logical mechanism of eggshell thinning due to pesti- cides (17. 26). All have a common problem; they do not fully explain why there should be interfamily or interspecific differences in susceptibility to DDE-caused eggshell thinning. However, there do seem to be real differences, at least between such species as Japanese quail (Coturnix cotiirnix) and mallards (Anas platyrhyn- clios) (15). Since the species we studied are related in their food habits (all except the cattle egret feed on aquatic organisms, and most feed mainly on fish), we performed partial correlation analyses on the combined data, but with the herring gull data excluded. The re- tults of these analyses (Table 5) should be viewed with caution, since they represent combined samples. The simple correlation of mercury with percent thickness index for addled eggs apparently carries over to the larger groups in which both addled and viable eggs were combined. When only viable eggs were considered, DDE, dieldrin, or PCB was the most important, and mercury was not correlated at all. The results do not mean that any of the re,sidues which had significant partial correlation coefficients are importantly related 34 Pesticides Monitoring Journal to eggshell thinning in all of the species in the sample. Indeed, it is evident that this was not the case. However, the results do indicate that these residues were import- ant to many of the species in the sample. Thus, wc con- sider that both DDE and dieldrin are important to many species, especially herons, and PCB is important to mergansers and perhaps some other species as well in respect to eggshell thinning. It appears that DDT, TDE, and BHC have very little relation to shell thinning. The importance of mercury is puzzling, however, since its significance occurred in addled eggs but not in viable eggs. Larger sample sizes are needed for individual partial correlation analysis of each of the species studied here. We noted consistently high correlations (P<0.001) be- tween DDE and PCB's in all of our samples. This may be the result of similar storage characteristics in fat, similar distribution patterns in ecosystems, or causal relationships in fat storage. With regard to causal re- lationships in fat storage, Lichtenstein {23) reported increased mortality of housefiies when both DDT and PCB's were present as opposed to DDT alone, and Street (30) demonstrated a negative effect of DDT fed to rats on storage of dieldrin. However, in our samples there was a significantK positive correlation between dieldrin and DDT - TDE. suggesting little or no negative effect of DDT + TDE on dieldrin levels. Heath et al. (15) found no synergism between DDE and PCB's in toxicity tests on Japanese quail, but there remains a great deal to be learned of the relationships betv\een PCB's and the other organochlorines. It is entirely possible that no causal relationships arc involved, and that the high correlations observed are due solely to similar distribution patterns of the organochlorines in ecosystems. All but 3 of the 34 simple correlation coefficients which we determined for DDE were negative, while only 24 were negative for dieldrin. We therefore feel that DDF significantly affects many species, but that the residue concentrations needed to cause a given degree of egg- shell thinning vary greatly among species. For example, herring gull eggs had approximately 40 times as much DDE as black tern eggs, \et the mean change in thick- ness index was only 4% greater for herring gulls. Differ- ences such as these, even when log transformations are used, reduce the magnitude of the correlation coefficient for the combined data, although DDF may cause egg- shell thinning in both species. In most cases, the R- values (Table 5) were rather low, although many were significant b\ the F-tcst. These chemicals are by no means the only ones to which birds are subjected in greater amounts today than in former times. Many natural environmental and physiological factors such as heat, humidity, and nutrition can affect eggshell thickness (27). Variation due to these other factors may mask the effects which we attempted to measure. However, it is clear that DDE and dieldrin are importantly related to eggshell thinning in many species, and that PCB's are similarly related to egg- shell thinning in mergansers. When we compared the mean change in thickness index to the mean of the sum of all organochlorines for each species, a trend toward a linear relationship on a log-log basis was evident (Fig. I). However, the yellow-crowned night heron and pied-billed grebe data did not appear to fit the line. No statistical analysis of this relationship was possible because of differences in sample sizes. 30 0- (T) © 2 0 0- ^ ® 10 0- ^. ^ 1 UA^ a red necked grebe 1 5 0- c - ^ (g) ©6 pied billed grebe ^ C white pel. can Thick 1 ^-~, D double -crested cormoroni (n) E great blue heron c F green heron y G little blue heron i H cQllle egret & /g\ 1 common egret H J snowy egret c: K louiiiono heron ^ 1 0- L block-crowned night heron M yellow-crowned rrghf heron - N omericon b.ttern - O hooded mergonier ~ P common merganser 0 5- Q red-breasted mergonier M - ^ S block lern D So o 5 O o o o O O O Mc.in Ttiuil <)rs:;in(ich!orlnc Rcsiducv 1 111 ppni. Itpnt-"ci'jhl h;iNiv) FIGURE !. — Mean shcll-rhickiicss index changes and mean residue levels for each species llog-log basis) See Appendix for cliemic.il names of compounds discussed in ttiis paper. Acknowledgments- Curl Richter and the following museums allowed us to measure eggs in their collections: Western Foundation of Vertebrate Zoology; Museum of Vertebrate Zoology. University of California. Berkeley Chicago Field Vol. 7, No. I, Junh 1973 35 Museum of Natural History; Museum of Natural Sci- ence, Louisiana State University; and Zoology Museum. University of Wisconsin. We are grateful to the field personnel of the following agencies: Louisiana Wildlife and Fisheries Commission. Wisconsin Department of Natural Resources. Lac Qui Parle Wildlife Management Area in Minnesota, and Seney National Wildlife Refuge in Michigan. All of these people spared no effort to help us in our field collections. In addition, we thank T. C. Grubb, Jr.. W. J. Neidermyer. C. H. Richter. W. Sim- mons, H. C. Wilson. D. W. Anderson. David Strohmeyer. and P. G. Connors for field assistance. H. T. Hendrick- son identified specimens by electrophoresis, R. G. Heath and J. H. 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A survey of mercury residues in aquatic bird eggs in the Can.adian prairie provinces. Trans. N. Am. Wildl. Natl. Res. Conf. 36:138-152. (32) I'crmcer. K.. and L. M. Reynolds. 1970. Organo- chlorine residues in aquatic birds in the Canadian prairie provinces. Can. Field-Naturalist 84(2): 1 1 7-130. (33) Wiemcyer. S. N.. and R. D. Porter. 1970. DDE thins eggshells of captive American kestrels. Nature 227-737- 738. .36 Pesticides Monitoring Journal International Cooperative Study of Organochlorine and Mercury Residues in Wildlife, 1969-71 A. V, Holdeni ABSTRACT A two-part collahoralivc study of organochlorine pesticides, polycMorinated hiphenyls (PCB's), and mercury residues was carried out by 26 laboratories in 12 countries. The fust pari involved the analysis of three test samples containing organochlorine residues and one group of test samples con- taining mercury. One organochlorine sample contained seven pesticides or derivatives added to corn oil: a second was a standard solution of a PCB formulation in hcxanc: and the third a homogenate of cormorant (Phalacrocorax carbo) muscle containing mainly PCB's. With few exceptions, agree- ment among the analysts involved was reasonably good and acceptable for monitoring wildlife residues. Coefficients of variation for the various organochlorincs were front ± 10% to ± 17%. The test samples containing mcrciirv included a group of freeze-dried homogeiiates of the muscle tissue of pike (Esox lucius) and an ampoule of melhylmercury dicyandiamide in water: the samples were analyzed for total and melhylmercury. Again, agreement was reasonably good, although oidy four laboratories reported total mercury values and eight, methylmerciirv values. The second part of the program required the sampling and analysis of several species of wildlife from both terrestrial and aquatic environments, including fish, shellfish, and the eggs of birds. Samples were taken in specified numbers and at specied times, from both areas considered to be free of any pesticide usage and areas known or believed to be seriously polluted. Eggshell thickness indices were also determined. The results of the wildlife analyses demoit- strated the difficulties in selecting species appropriate for international monitoring programs, in identifying (before analysis) areas of high contamination, and in relating con- centrations to measurable biological effects. Saniples of cniy one species from areas regarded as unpolluted in differeni countries contained a wide range of organocldorine con- centrations. The PCB levels in niussels from such areas con- tained 0.01 In 0.67 mg/kg, and DDE levels in herring ranged I ' Freshwater Fisheries Laboratory, Pitlochry, Scotland (acting as co- ordinator). Vol. 7, No. 1, June 197.1 from <0.Q1 to 0.30 mg/kg. The differences between residue results for samples in this second part of the study were much greater than the analytical variations estimated from the first part of the study. Introduction A series of voluntary international cooperative studies of residues of pesticides and other contaminants in the environment has resulted from a meeting sponsored by the Organization for Economic Cooperation and De- velopment (O.E.C.D.) held in Paris in 1966. A report on the second study (1967/1968). published in an earlier issue of this Journal (/). was presented at the Second O.E.C.D. Technical Meeting on Pesticides in the En- vironment, held in the Netherlands in 1969: also at that meeting, a further study was designed for the period 1969-71. The findings of this third study are reported here. At the original meeting m Paris, proposals for an inter- national monitoring program were made, but most countries were unprepared for such work. Since that time, interest in the subject of environmental pollution has increased, and a recommendation for global moni- toring was passed at the United Nations Conference on the Human Environment in Stockholm in 1972. For the monitoring of organochlorine residues using indicator species, it is essential that all laboratories engaged in the work be able to reach agreement, both qualitatively and quantitatively, on the residues present; suitable exchange samples provide a means for assessing such agreement. The species selected for monitoring must be capable of providing an adequate number of samples for the calcu- lation of the mean contamination level of each popula- tion studied and must be sufficiently abundant to allow 37 adequate sampling for analytical purposes without en- dangering the population. Adequate knowledge must also be available beforehand on the variation of residue levels between individuals of the population, so that the number of individuals taken for analysis will provide a mean value of the contamination level of the population. of sufficient accurac\' for the statistical evaluation of differences between populations or between successive sampling occasions. For the final assessment of the biological significance of a particular residue, more ex- tensive knowledge of the effects of residues at various contamination levels is required than exists at the present time. In the second collaborative study (/). the agreement among analysts on the presence and concentrations of dieldrin, DDE, TDE. and DDT in exchange samples was reasonably good onh for material which required the minimum of processing prior to gas-liquid chromato- graphic (GLC) analysis. With such samples, the coeffici- ent of variation was it 25-30'~f. For more difficult samples, the coefficient of variation was ± .lO-eC^f. No allowance for or determination of polychlorinated biphenyls (PCB's) was made. In addition, distribution of residues among individuals of most populations of star- lings and pike was found to be skew. For the detection of a 25% difference in contamination levels, it was calculated that 50 individuals would be required; for a 75% difference, 10 individuals were sufficient. The third study included analysis for organochlorines and extended the analytical requirements to PCB's and mercury, and appropriate exchange samples were cir- culated. The wildlife samples, both freshwater and marine, included fish and fish-eating birds, sampled ac- cording to a detailed program. The second studv had been confined to areas believed to be uncontaminated by direct application or disposal of pesticides, but in this third study both uncontaminated and contaminated areas were selected for sampling, in the hope of estab- lishing the existence of differences between contamina- tion levels. In addition, where the eggs of certain species of birds were to be sampled, measurements of eggshell thickness indices were requested in an attempt to cor- relate these with organochlorine residue levels. In all. 26 laboratories in 12 countries took part in this third study; these laboratories are identified in Table I. A total of 18 laboratories participated in the analytical program, 17 in the nine member countries of O.E.C.D.. and in addition the analytical laboratory of Euratom at the European Community Commission Joint Research Center in Ispra. Italy. Most of the laboratories had taken part in the second study. Since the second study, analytical methods have been developed for the separa- tion and measurement of PCB"s: therefore, it was an- 38 TABLE I. — Laboratories participating in international cooperative study of organochlorine and mercury residues in wildlife, 1969-71 Country Canada Denmarlc Euratom (Italy) Finland Gcrmanv Netherlands Norway Portugal Spain .Sweden Participating Laboratories I'nitcd Kingdom United States Ontario Researcli Foundation (ORE), Sheridan Park. Ontario, Canada. Fisheries Research Board of Canada (FRB), St. Andrews, New Brunswick. Canada. Veterinary and Agricultural College, Depart- ment of Pharmacology and Toxicology, 13 Biilowsvej. Copenhagen V, Denmark. Analytical Laboratory, Euratom, European Com- munity Commission Joint Research Center, Ispra, Italy. State Institute of Agricultural Chemistry (Agric). 00170 Helsinki. Finland. State Veterinary Medical Institute (Vet. Med.), 00550 Helsinki. Finland. State Game Research Institute, 00170 Helsinki, Finland. Reactor Laboratory, State Institute for Technical Research. Otaniemi. Finland. Department of Ecological Chemistry. 800 Mu- nich 15, Landwehrstrasse 61, Federal Republic of Germany. Federal Institute for Fisheries Research, 2 Hamburg 50. Palmaille 9. Federal Republic of Germany. Institute of Veterinary Pharmacology and Toxi- cology (Vet. Tox.), University of Utrecht, Utrecht, Netherlands. Central Institute for Nutrition and Food Re- search (CIVO). Utrechtseweg 48, Zeist. Neth- erlands. National Institute of Public Health (RIV). Stcrrcnbos 1, Utrecht, Netherlands. Veterinary College of Norway. Department of Pharmacology. Oslo 4. Norway. Agricultural College of Norway, Department of Zoology, Vollebek. Norway. Laboratory of Phytopharmacology, Quinto do Marques, Oeiras, Portugal. Institute of General Organic Chemistry, Juan dc la Cicrva ,1, Madrid-6, Spain. Special Analytical Laboratory. Swedish Environ- ment Protection Board, Stockholm, Sweden. Swedish Museum of Natural History. Stockholm, Sweden. Royal Institute of Technology, Department of Nuclear Chemistry. Stockholm. Sweden. Laboratory of the Government Chemist (LGC), Cornwall House. Stamford Street, London SEl 9NQ. U.K. Ministry of Agriculture. Fisheries and Food (MAFF), Fisheries Laboratory, Brunham-on- Crouch, Essex, U.K. Nature Conservancy (NO. Monks Wood Ex- perimental Station, Abbots Ripton, Hunting- donshire, LI.K. I5epartmcnt of Agriculture and Fisheries for Scotland. Freshwater Fisheries Laboratory (FFL), Pitlochry, Perthshire, Scotland. U.S. Department of the Interior (USDI). Fish and Wildlife Service, Patuxent Wildlife Re- search Center. Laurel. Md. 20810. U.S.A. U.S. Environmental Protection Agency (EPA). Gulf Breeze Laboratory, Gulf Breeze Fla 32561, U.S.A. Pesticides Monitoring Journal ticipated that the measure of agreement among labora- tories in respect to the organochlorines would be im- proved. Several laboratories were also engaged in mercury analysis. Interlahoiatory Quality Evaluation Program for Organochlorine and Mercury Residue Analyses DESCRIPTION OF TEST SAMPLES Four types of test samples were circulated among the participating laboratories, for analysis by the methods each currently used. An outline of the methods used for organochlorine analysis is given in Table 2; the tech- niques involved in the analysis of the mercury check samples are discussed later. Sample No. 1 — a mixture of seven organochlorine in- secticides or derivatives in corn oil together with a sample of the unspiked oil. This sample was distributed by Mr. W. L. Reichel, Patu.xent Wildlife Research Center, Laurel, Md., U.S.A. On receipt of the report from each laboratory, the correct analysis for the added residues was provided. TABLE 2. — Analytical techniques for organochlorine analysis Laboratory Method of Extraction ' Cleanup Pre-GLC Separation GLC Packing Canada ORF cthcr-hexane (1:1) Carbon-Celite at —70° Florisil 4% SE-30/6% QF-1 FRB hexane Alumina Silica 4% SE-30 Denmark ethanol-hexane (3:1, cold), then 10% ether in petroleum ether (cold) Fuming H„SO, SF-96/QF-1 Euratom .icctonitrile and petroleum ether Florisil Florisil 1) 3?J DEGS 2) 5% DC-200/7.5% QF-1 3) 1.5% OV-17/1.95% QF-1 Finland Agric. hexane or acetone-hexanc (1:9) DMF/hexanc or alumina Silica 1 ) Apiezon L 2) E. glycol adipatc Vet. Med. ciher on column (cold) H„SO, or TLC TLC 1.25% SF-96/3.75% QF-1 Germany Munich benzene Alumina 3% OV-I Hamburg hexane Alumina Silica 1 ) DC-200 21 DC-200/QF-1 Netherlands Vet. Tox. hexane Alumina Silica 1 ) DC-200 2) QF-1 civo hexane Alumina Silica 1) 3% OV-1 2) 1.8% OV-1/2.7% QF-1 Norway ether on column (cold) H,SO, or "alcoholic KOH 1 ) 10% QF-1 2) 4% SF-96 Portugal hexane DMF/hexanc, alumina 1) 5% QF-1 2) 4% SE-30/6% QF-1 Spain hexane /acetone (4:6) CH,N/hexane Florisil 1 ) 9% DC-200 2) 5% DC-200/7.5% QF-1 Sweden hexane 1) SiUca 2) KOH 3) fuming H.SO, 1 ) SF-95 2) 1.75% SF-96/3.75% QF-1 United Kingdom LGC acetone /hexane (1:2) DMF/hexanc, alumina Silica 1 ) SE-52 2) Apiezon L FFL hexane Alumina Silica 1)6% D&200 2) 4% DC-200/6% QF-1 United States USDI hexane CH,CN/hexane Florisil. TLC 1) 3% OV-1 2)3% XE-60 EPA petroleum ether CH,CN/hexane Florisil 1)3% DO200 2) 5% QF-1 3) 1.5% DC-200/2.5% QF-1 ^ Hot extraction, unless otherwise indicated. Vol. 7, No. 1, June 1973 39 enabling the laboratories to check for errors in stand- ards or technique before proceeding with the analyses of wildlife samples. Sample No. 2 — an ampoule conlainint; a solution of a 60% technical PCB mixture (Clophen A. -60). This sample was distributed by Dr. J. H. Koeman, In- stitute of Veterinary Pharmacology and Toxicology. Utrecht, Netherlands. After laboratories reported their values for the PCB content of this solution, analysts were informed of the true concentration. Sample No. 3 — a homogenate of the total body lless hill, legs, and feathers) of a cormorant (Phalacrocora.\ carbo) found dead in the Netherlands in 1970. The weight of fresh tissue (ground with anhydrous sodium sulphate) was given with the sample. This sample was primarily for PCB analysis, although many laboratories examined it for other organochlorine residues as well. It was distributed by Dr. J. H. Koe- man, Utrecht. Netherlands. Sample No. 4 — a group of freeze-dried homogenates of the muscle tissue of pike (Esox lucius), and an ampoule of methylmercury dicyandiamide in water. These samples were for the analysis of mercury in both methyl and total forms and required the addition of a specified amount of water before analysis to reconsti- tute the tissue. Two specimens (A and B) were identi- cal, but to one (B) was added to contents of the ampoule before analysis. A third tissue sample of high mercury content (C) was analyzed separately. A fourth tissue sample (D) was included for experience in analyzing this type of sample, but results were not evaluated. All re- sults were recorded on a wet-weight basis, and the difference between specimens A and B calculated. The samples were distributed by Dr. .S. Jensen. Special Analytical Laboratory, Lanibrukshogskolan. Uppsala. Sweden. ANALYTICAL PROCEDURES (TEST SAMPLES) The methods used for the analysis of organochlorines varied widely (Table 2). and sometimes techniques dif- fered for the corn oil and cormorant samples. For the latter, extraction solvents included ether, hexane. hexane/acetontrile. hexane/ acetone. and hexane/ acetonitrile/methylenc chloride. Fewer analysts used a solvent partition cleanup than an adsorbent column process (usually Florisil or alumina), while separation of PCB"s from other organochlorines was usually achieved with silica columns. A wide variety of station- ary phases was used in the GLC analysis, including SE-30, SF-96, DC-200, OV-1, OV-17, QF-1. XE-60, 40 Apiezon L. DEGS, and mixtures of QF-1 with other nonpolar phases. No two laboratories used the same complete procedure for extraction, cleanup, and GLC analysis. For the calculation of PCB concentrations, a wide variety of methods was also used. Many analysts used peak heights, with the number of peaks varying from one to six. Others used calculations of peak area: by electronic integration using nine peaks; by a total area method involving cutting and weighing: or, in some cases, by the equivalent of area measurement involving the product of peak height and relative retention time. One laboratory measured the optical density on thin layer plates. The reference solutions employed were usually 50% or 60% chlorinated formulations, but one laboratory based its measurements on DDE or dieldrin standards which had previously been calibrated with reference to a PCB formulation. The analytical methods for mercury residues are referred to later. DISCUSSION OF RESULTS (TEST SAMPLES) The corn oil sample (No. 1 ) was analyzed by more laboratories (17) than the other samples, with 2 labora- tories using two separate methods, giving a total of 19 sets of results. Fourteen laboratories analyzed the PCB solution (No. 2): 14 analyzed the cormorant sample (No. 3) with 3 of them using more than one method, giving a total of 18 sets of results for the PCB con- centration. The mercury samples (No. 4) were ex- amined by nine laboratories, some doing only methyl or total mercury analyses. Several laboratories, due to lack of experience, reported difliculty in the analyses for methylmercury. Sample No. I Although this sample contained seven different organo- chlorine residues, most laboratories reported only six, being unable to identify or quantify dichlorobenzo- phenone (DCBP). The results of these analyses are given in Table 3. One laboratory in the United Kingdom (LGC Laboratory) used two different GLC columns for separate analyses, and one laboratory in Finland (Agric.) used different processing techniques for separate analyses. One laboratory in West Germany (Hamburg) reported only three of the seven residues present and estimated dieldrin approximately: this dieldrin value was not included in subsequent calculations. The same lab- oratory was unable to estimate heptachlor epoxide or o./^'-DDT. An examination of the distribution of the values recorded for the individual residues suggests that the values for dieldrin, c.p'-DDT, and p,p'-DDT are normally distrib- Pesticides Monitoring Journal TABLE 3. — Analyses of test sample no. 1 — spiked corn oil Concentrations in MG/KG Laboratory Heptachlor Epoxide p,p'-DDE p,p-TDE p,p'-DDT o,p'-DDT Dieldrin DCBP Canada FRB ORF 3.3 3.5 11.9 12.0 5.7 5.9 3.8 4.0 1.1 2.5 4.0 4.7 1.9 Denmark 3.2 13.5 6.0 4.1 3.5 3.0 - Euratom 4.2 13.8 7.5 4.5 3.5 4.9 1.9 Finland Agric, (two methods) Vet. Med. 4,0 4.0 3.4 15.1 15.3 13.1 6.7 6.9 5.9 4.9 5.0 4.4 4.1 4.0 3.6 4.9 5.0 4.2 — Germany Hamburg Munich 4.8 11. 1 10.3 6.1 9.6 3.4 5.0 3.2 1 1.9 5.0 — Netherlands CIVO RIV Vet. Tox. 4.3 3.3 3.0 14.8 9.7 11.7 7.0 6.3 6.6 4.4 3.6 3.1 4.2 3.7 5.2 3.9 4.3 — Norway 2.7 16.5 7.9 5.5 3.7 6.0 - Spain 4.S 14.2 3.6 3.4 2.0 3.1 — United Kingdom FFL LGC (two methods) 4.2 3.4 3.2 15.3 11.7 11. S 6.7 6.7 7.0 4.1 3.7 3.7 3.6 2.9 2.7 4.5 4.6 4.6 1.8 United States EPA USDI 4.0 3.0 14.7 14.2 7.6 6.1 5.2 4.6 3.5 3.2 5.0 4.4 1.7 True Spike Values 4.0 15.0 7.5 4.5 3.5 5.0 2.0 NOTE: — = no value reported. ^ Approximate estimate only; value not included in subsequent calculations. uted: however, there is some iJoubl about the distribu- tion of the values for p.p'-IDE, p.p'-DDE, and, in particular, heptachlor epoxide. The results for heptachlor epoxide appear to fall into two groups, one around 3.2 mg/kg and the other around 4.1 mg/kg. The statistical analyses of the data, referred to in the following para- graphs and summarized in Table 4, were based on the assumption that distribution is in fact normal. The mean values for the residues found were in all instances below the true values, suggesting that some loss of residues in processing was experienced by most laboratories. The recoveries ranged from 87.8% for p.p'-DDE to 96.2% for o.p'-DDT. Yet, of the six residues which were identified by most analysts, two laboratories obtained values within ±5% of the true values for five of these, and three were within ± 10% for five residues. At the level of estimation of the residues in the spiked sample, most laboratories reported that they did not find any residues in the unsplked corn oil. Generally, a re- covery of at least 90% of all residues in this sample was possible, but no relationship between the methods used for extraction or cleanup and the efficiency of recovery could be found (Tables 3 and 4). The laboratory of the State Institute of Agricultural Chemistry, Helsinki, com- pared the alternative cleanup techniques of de Faubert Maunder et al. (2) and Holden and Marsden (if), and obtained remarkably similar results. The laboratory also used two different stationary phases (Apiezon L and ethylene glycol adipate) in two instruments, several residues being estimated on both instruments, and each being determined by triplicate analy.ses: these mean residue values are given in Table 3. The results suggest that the differences between analysts do not necessarily lie in the procedures adopted for cleanup or GLC an- alysis, but may be due to variation in standard solutions or in the methods of preparation of the initial extract. Overall, the results from this sample suggest that there has been an improvement in the agreement among analysts since the second study in 1967/1968 (/). The coefficients of variation for five organochlorine residues obtained for two samples in the second study (/) and for the corn oil sample in the present study are given in Table 5. Both the chicken egg homogenate sample of 1967/1968 (prepared from chickens fed with a Vol. 7, No. I. June 1973 41 TABLE 4. — Summary of analyses of lest sample no. 1 — spiked corn oil z o i- o z =^ ? Concentrations in mc/kg is t; H D S z — M W o Bi Z < >• Compound z o H z ss„ OS < < < H pi hi p si ggs Z a. J M i>s 2=5 o t 2 wag u ui y o; wi Z IS ^5 ^S^ 3 ^ 2 w as > II. 0. ? o £ < o o-mu Heptachlor epoxide 18 4.0 2.7- 4.8 3.68 ±0.62 ±16.8 8 in 18 92.0 Dieldrin 1 18 5.0 3.0- 6.0 4.52 ±0.72 ±15.9 12 in 18 90.4 p,p'-DDE 19 15.0 9.7-16.5 13.20 ±1.90 ±14.4 7 in 19 87.8 p,p'-TDE -n 7.5 5.7- 7.9 6.62 ±0.65 ± 9.8 11 in 17 88.3 p.p'-DDT 19 4.5 3.1- 5.5 4.23 ±0.68 ±16.1 8 in 19 94.0 o.p'-DDT • 16 3.5 2.0- 4.2 3.37 ±0.60 ±17.7 9 in 16 96.2 DCBP 4 2.0 1.7- 1,9 1.82 — — 4 in 4 91.0 ' When two abnormaUy low values from Denmark and Spain were excluded (values less than 3 times the standard deviation), the range was 3.9-6.0 mg/kg with a mean recovery of 93.7%. = Excludes one unusually low value from Spain and one high value from West Germany (Munich), values differing from the mean by more than 4 times the standard deviation. ■1 Excludes one low value from Canada (FRB), a value less than the mean by 3.8 times the standard deviation. pesticide mixture) and the spiked corn oil sample of this study required a significant amount of processing, including cleanup and in many cases separation of residues prior to GLC analysis. Nevertheless, the results for the spiked corn oil are distinctly better than those obtained for the chicken egg in the previous study, al- though understandably not as good as the values for the standard solution in hexane which required no more than dilution and direct injection for GLC analysis. Coefficients of variation in the range ± \07r to ± 15% for different organochlorine residues in samples requiring complete processing are perhaps the best that can be expected at the present time. laboratory obtained two estimates of 9.6 and 11.0 mg/ liter with two different types of GLC column. By com- parison, the coefficients of variation for the results of analyses for six different organochlorine pesticides in corn oil (Sample No. 1) ranged from ± 9.89r to ± 16.8%. For this commercial PCB mixture, the agreement among the analysts using appropriate reference solutions was very satisfactory despite the wide variety of methods of calculation; however, there seems to have been some variation due to the different commercial products used as reference standards. Sample No. 2 (PCB solution) This sample, an ampoule of a solution of Clophen A. -60 in hexane (a 60% chlorinated PCB). was analyzed j'or comparing it with" a solution of an appropriate PCB standard chosen by the analyst (Table 6). The true value given subsequent to the analysis being reported waS, 9.8 mg/liter of Clophen A. -60. Fourteen laboratories re- ported, two giving estimates by two different methods. Twelve results were obtained using 60% chlorinated PCB standards, the range of values being 8.4 - 12.6 mg/ liter, the mean 10.17 mg/liter, and the coefficient of variation ± 10.2%. Two of the three laboratories using Clophen A. -60 reported a concentration of exactly 10.0 mg/liter: two of three using Clopen A. -50 as reference estimated the concentration as 8.0 mg/liter. One laboratory using Phenoclor DP. 6 obtained a value of 12.6 mg/liter. Seven results based on Aroclor 1260 gave a range of 9.0 to 11.4 mg/liter with a mean of 9.97 mg/liter (coefficient of variation ± 9.7%). One Sample No. 3 (cormorant) The analysis of the homogenate of cormorant tissue involved extraction, cleanup, and, where possible, the separation of PCB residues from other organochlorines. In addition to the PCB residues, high concentrations of hexachlorobenzene and p.p'-DDE and smaller concen- trations of p,p'-TDE and dieldrin were estimated by most analysts. Lindane (y-BHC), p.p'-DDT. and hep- tachlor epoxide were reported by a few laboratories. The results are given in Table 7. Fourteen laboratories reported on the sample, three giving several estimates of the PCB content by various methods of calculation or analysis. The reference solu- tions used included 50%, 54%. and 60% chlorinated types. The overall range of all results reported was 240- 525 mg/kg in the original tissue, but for eight results (using a 60% chlorinated reference solution) the range was 279-462 mg/kg. with a mean of 374 mg/kg and a 42 Pesticides Monitoring Journal TABLE 5. — Comparison of analytical efficiencies for determination of organochlorine residues in 1967-68 and 1969-71 samples Coefficient of Variation and Number of Results ( ) Compound 1967-68 (7) 1969-71 Standards in Hexane Chicken EOG Spiked Corn Oil Hcptachlor epoxide Dieldrin p.p'-DDE P,P'-TDE p.p'-DDT ± 11.0% (15) ± 7.4% (17) ± 9.9% (16) ± 7.5% (17) ± 7.0% (17) ±28% (15) ±32% (15) ±51% (11) ±31% (15) ±16.8% (18) ±15.9% (18) ±14.4% (19) ± 9.8% (17) ±16.1% (19) TABLE 6. — Analyses of test sample no. 2 — PCB solution Laboratory Reference PCB Concentrations IN MG/LlTER Canada FRB ORF Aroclor 1260 Aroclor 1260 9.0 11.4 Denmark Clophen A. -60 9.3 Euratom Clophen A.-50 8.4 Finland Agric. Vet. Med. Clophen A.-60 Clophen A. -60 10.0 10.0 Netherlands CIVO RIV Clophen A.-60 Phenoclor DP. 6 10.4 12.6 Norway Clophen A. -50 8.0 Spain Clophen A. -50 8.0 United Kingdom FFL (twoGLC columns) LGC Aroclor 1260 Aroclor 1260 Aroclor 1260 DDE 11.0 9.6 10.4 8.9 United States EPA USDI Aroclor 1260 Aroclor 1260 9.1 9.3 True Value Clophen A.-60 9.8 coeflRcient of variation of ± 15.8%. This agreement among the analysts would seem to be very satisfactory. in view of the many differences in extraction, cleanup. and separation techniques and the different methods of estimating the PCB concentrations. The coefficient of variation among these results is within the range of values found for the pesticides in the corn oil sample (No. I ) which required less processing. Of the other residues found, 12 results were reported for p,/7'-DDE, from 4.5 - 19.5 mg/kg. Some laboratories apparently did not correct for PCB interference with this residue but those which did found concentrations of p.p'-DDE from 4.5 to 11.0 mg/kg. Eight values for dieldrin were between 0.9 and 2.2 mg/kg but a ninth Vol. 7, No. 1, June 1973 value was less than 0.1 mg/kg. Failure to obtain a complete separation of PCB's from p.p'-TDE and p.p'- DDT would have resulted in significant errors for these residues in this particular sample; however, only two values of p.p'-DDT were recorded, and both were very low. The only other significant residue found was hexa- chlorobenzene (HCB), for which six values ranging from 22.3 to 48.7 mg/kg were reported, but not all labora- tories recognized or were able to determine this sub- stance. This sample was not particularly easy to analyze, but the agreement obtained was good for the major con- taminant, and much better than for the residues in the sprat homogenate used in the previous study. The higher concentrations in the cormorant sample probably contributed to the better agreement among analysts. Sample No. 4 (mercury in fish) Analyses of the three samples of fish tissue for total mercury and/or methylmercury were made by nine laboratories. Values for total mercury from four of them were in good agreement, and the eight sets of data on methylmercury were in reasonably good agreement (Table 8). The mean value for the mercury content of Sample A was 0.152 mg/kg as methylmercury and 0.165 mg/kg as total mercury. Sample B was prepared from an identical aliquot of Sample A. with the addition of u fixed amount of an aqueous solution of methylmercury dicyandia- mide. The mean values calculated for this spiked solu- tion were equivalent to 0.36 mg/kg as methylmercury and 0.39 mg/kg as total mercury, the true value being given as 0.35 mg/kg. For Sample C, the mean values were 1.89 mg/kg as methylmercury and 2.12 mg/kg as total mercury. The coefficient of variation among the eight laboratories reporting methylmercury was ± 20% for the spike, and ± 28% for Sample C (high mercury). The methylmercury estimated in Sample C represented about 90% of the total mercury found. The methods used for methylmercury analysis varied among the laboratories, but all used either a hydro- chloric acid, hydrobromic acid, or cupric bromide re- agent to liberate the methylmercury from the fish tissue, followed by extraction into an organic solvent. Some analysts used a cleanup stage with cysteine acetate and re-extraction into a further solvent, but others did not find this step necessary. The concentrations of methyl- mercury in the extracts were determined by electron- capture gas chromatography in all laboratories. The Euratom Laboratory determined total mercury using neutron activation analysis, but all other laboratories used flameless atomic absorption, with different types of digestion mixture. 43 L TABLE 7. — Analyses of test sample no. 3 — cormorant Concentrations in mg/kg Laboratory HCB l-BHC Heptachlor Epoxide DiELDRIN p.p'-DDE p.p'-TDE p,p'-DDT PCBs PCS Reference Canada FRB ORF 34.0 48.7 0.50 0.13 1.13 2.02 14.3 18.4 1.56 2.92 402 462 Aroclor 1254 Aroclor 1260 Denmark 14 374 Clophen A.-60 Euratom 3.3 <0.1 13.3 2.4 432 Clophen A.-60 Finland Vet. Med. Agric. (two methods) (1) (1) (1) 2.2 - 6.5 = 4.5 (') 4.5 4.1 279 525 450 Clophen A.-60 Clophen A.-50 & A.-60 Clophen A.-50 & A.-60 Germany Munich, (three methods) 395. 378, 360 Clophen T.-64 Netherlands crvo 44 19.5 400 Clophen A.-60 Norway 273 Clophen A.-50 Spain (1) 0.3 1.4 " 9.3 2.7 0.3 320 Clophen A. -60 United Kingdom FFL LGC, (two methods) 22.3 23 2S 0.08 0.08 0.97 0.9 1.1 = 8.2 = 9.7 = 10.0 1.5 1.4 1.6 0.18 283 345 340 Aroclor 1254 Clophen A.-60 DDE or Dieldrin United States EPA USDI 1.3 - 11 2.2 470 240 Aroclor 1254 Aroclor 1254 ' Detected, but value not estimated. ^ Corrected for PCB interference. TABLE 8. — Analyses of test sample no. 4 — pike homogenate Concentrations in mg/kg I.ABORATOR'^' Methyl Mercury Total Mercury A B B-A C A B B-A C Canada ORF 0.18 0.64 0.46 1.27 0,20 0.56 0.36 2.11 Denmark n.i4 0.46 0.32 1.97 Euratom 0.15 0.70 0.55 2.0 Finland Vet. Med. 0.14 n,50 0.36 2.35 Germany Munich 0.14 Norway 0.13 0.59 0,46 2.60 United Kingdo Tl FFL 0.18 0.56 0.38 2,0 0.13 0.42 0.29 2.18 LGC. (two 0.13 0.40 0.27 1.4 0,18 0.54 0,36 "> 1 methods ) 0.14 0.46 0.32 1.4 United States USDI 0.18 0.47 0.29 2.60 Mean 0.152 0.511 0.357 1.89 0.165 0.555 0.39 2.12 True Value 0.35 0.35 CONCLUSIONS (BASED ON TEST SAMPLES) The results of this section of the program represent a considerable improvement over those of the previous studies. Analysts using a variety of methods were able to achieve reasonably good agreement on the amounts of both organochlorine pesticide and PCB residues in wildlife samples requiring full processing, and the techniques for separation of PCB's from most organo- chlorine pesticides seemed to be adequate for this pur- pose. From the details available, there was no evidence that any one technique was consistently better than another. Where two methods were compared in the analysis of the corn oil sample, as reported by two laboratories, the within-laboratory agreement was ex- cellent. Although the estimation of PCB residues is clearly dependent on the reference formulation and the method of calculation (e.g., using the summation of peak heights or areas of one or more peaks), the general agreement on total PCB levels was nevertheless satis- factory, bearing in mind that the composition of the mixture of PCB isomers in wildlife is rarely typical of commercial mixtures. If international monitoring pro- grams for organochlorines and mercury are established, it is unlikely that any one method of analysis would be 44 Pesticides Monitoring Journal acceptable to all laboratories, but this study has shown that it is possible to achieve good agreement among laboratories using different methods in the hands of experienced analysts. Oifjanochlorinf Residues in Wildlife Samples SAMPLING PROCEDURES (WILDLIFE SAMPLES) This part of the study was intended to be more extensive than that in the previous 2-year program (/) and was concentrated on the aquatic environment, including where possible both ostensibly uncontaminated and recognizably contaminated areas, to determine whether significant differences in residue levels could be de- tected. The numbers of individuals selected were usually sufficient to confirm a two-fold difference, according to the results of the previous study. The soft tissue of fish and shellfish and the contents of the eggs of birds were selected for analysis. In addition, eggshell thickness indices were to be calculated for the eggs and, where possible, breeding success in an attempt to determine any biological effects of the residues on the bird population. The freshwater fish species selected were the pike (Eso.x liiciiis) or if not available, the roach (Rutilus rutiliis). or eel (Anguilla vulgaris). The marine species were the mussel (Mytilus edulis). herring (Clupea harerii,'us), or the sprat (Clupea sprattus) where the herring was not available. The bird species, which were all piscivorous, were to be chosen from the genera Ardea. Pelecanus. Podiceps, Uria. Alca. Sterna. Phalacrocorax. and Somateria. The numbers to be taken and the sampling times were specified as indicated below. The detailed procedures for sample collection and pre- paration were specified as follows: Pike, roach, or eel — 15 specimens to be collected before spawning from each of both uncontaminated and con- taminated sites, the individuals to be of uniform size. and if possible of the same sex. Five fish to be assigned randomly to each of three pools, and each pool to be homogenized from whole fish or from 10-g aliquot of lateral muscle taken at the midsection, avoiding depot fat. The six pools for each species were to he analyzed for organochlorine residues, and if possible mercury. Fat contents of tissues were to be determined if possible. Herrint: or Sprat — procedures were the same as for freshwater fish, except that eight fish were to be assigned to each pool. Mussel — to be collected from at least one contaminated site and one uncontaminated site in estuaries or at the months of large rivers. Thirty large specimens to be collected before spawning and divided randomly into y pools of 10. The soft parts were to be homogenized in each pool and analyzed for organochlorines and, if possible, mercury residues. Each pool was to be analyzed in cliiplicatc. Eggs froiji fish-feeding colonial birds — the species selected were to be sampled in areas where organo- chlorines were believed to be contaminating the water and in areas where they were not. The nests were to be counted in each colony. At each site, 10 eggs were to be taken from separate nests as soon after laying as possible, and each egg was to be analyzed separately for organochlorines and. where possible, mercury. The eggshell index was to be measured from the formula: Eggshell Index = ^^'g^' '" "^^ Length in mm x breadth in mm The measurements were to be made to 0.01 g or 0.01 mm, and the weight of the evacuated shell determined after drying for 1 month in air. The breeding success was to be studied by recording the number of breeding pairs in the colony, and the number of young reared during the season, each number being determined on 1 day during egg laying (number of pairs) or before dispersal (number of large young). RESULTS (WILDLIFE SAMPLES) Ten countries were involved in sampling at least one of the selected species: all 10 examined the mussel, 8 the herring (or sprat), and 6 the pike. Several countries reported difficulties in conforming exactly to the specified procedure, especially in respect to sampling times and numbers of individuals required, and it was not always possible to sample in both contaminated and uncon- taminated areas. Although the mussel, herring, and pike were well covered by a number of countries, enabling some degree of comparison to be made between coun- tries, most species of birds were examined by only one country, the eider (Somaleria moUissima) being sampled by three, and the heron i Ardea cinerea) by two countries. Three different species of tern (the Royal tern — Thalas- seiis maximus. common tern — Sterna hirundo. and Sandwich tern — Sterna sandvicensis and of the other selected genera, the eastern brown pelican (Pelicanus occidentalis carolinensis). were examined by one country. Summaries of the results reported in this study are given in Tables 9-15. In some instances, no clear distinction was made between contaminated and uncontaminated areas, and some contamination was of minor importance. Pollution by sewage from towns discharging to estuaries or the sea was sometimes assumed to be a source of organochlorine pollution, and in a few instances samples could not be obtained from appropriately polluted areas. Vol. 7, No. 1, June 1973 45 Because some countries could not obtain sufficient in- dividuals for analysis as required by the defined pro- cedure, statistical comparison of the data was not justi- fied, although two-fold or larger differences can be regarded as significant where at least 10 individuals were analyzed. Where residues were not detected, the limit of detection was stated. Moreover, the analytical results were incomplete since some residues were not analyzed for by all laboratories. Both marine and freshwater species usually contained dieldrin, DDE. TDE, and DDT, as well as PCBs: however, some laboratories did not indicate whether analyses for all these residues had been attempted. Mercury was not determined by all laboratories since the necessary procedure was not available to all those engaged in the examination of organochlorines. A few laboratories reported on residues of HCB, n-BHC, and y-BHC, although evidence of confirmation was not necessarily given. A discussion of the results obtained for the various species is given below: Mussel (examined hy 10 countries — Table 9) Most investigators analyzed pools of 10 mussels, as required by the program, but in a few cases the pools TABLE 9. — Analyses of wildlife samples — mussels Number of Mean Values in mo/kg Location Mussels PoLLirrioN Category IN Sample Dieldrin DDE TDE p.p'-DDT PCB's Kg Canada Miramichi Bay M) 0.02 0.02 0.01 0.01 0.14 0.02 Polluted Denmark Vejle t 0.005 0.005 0.004 0.002 0.06 Slightly polluted Esbjerg 3 0.011 0.016 0.004 0.004 0.28 Slightly polluted Finland Tvarminnc 60 J <0.006 0.170 0.95 0.42 Slightly polluted Norway 0yeren 10 < 0.005 0.005 < 0.005 <0.005 <0.005 Polluted Langen 10 < 0.005 0.005 < 0.005 <0.005 < 0.005 Unpolluted Spain Garcia Sola 2 0.003 0.46 0.002 0.009 0.13 PoUuted Orellana 4 0.003 n.48 0.044 < 0.006 0.12 Polluted Sweden 1970 Bolmcn in 0.018 0.007 0.014 0.030 0.45 Slightly polluted Storvindlen 10 0.006 <0.001 0.003 0.019 0.28 Unpolluted 1971 Bolmen 10 0.022 <0.001 0.010 0.087 0.36 SlighUy poUuted Storvindlen in 0.006 <0.001 0.010 0.040 0.29 Unpolluted United Kingdom Abberton Res. 13 0.68 Unpolluted River Chelmer 15 0.65 Polluted Loch Leven 10 0.004 0.030 0.016 0.009 <0.01 0.08 Slightly polluted NOTE: Where residues were not detected, the limit of detection was stated. "^ Samples from West Germany. 48 Pesticides Monitoring Journal ranged from 0.27 to 9.3 mg/kg. The mean eggshell thickness index of 2.16 in the Finnish sample was significantly different (at the 5% level) from that of the Norwegian sample, 2.28, and the mean PCB value was about seven times greater. The eggshell thickness index was unfortunately not given for the Danish eggs, which contained the most PCB's. Tern and pelican eggs (examined l^y three countries- — Table 15) The eggs of three species of tern and one species of pelican, although not strictly comparable, are discussed collectively because of the information given, both on residue levels and eggshell thickness indices, together with some observations on the breeding success. Two TABLE 12. — -Analyses of wildlife samples — eel Number of Mean Residi^s in mg/kc Location Eels in Sample Pollution Category DiELDRIN DDE TDE P.p'-DDT PCB'S Ho Canada Chamcook Lake 3 <0.02 0.55 <0.01 0.21 0.63 0.35 Unpolluted St. John River 10 <0.02 0.57 0.27 0.32 0.75 0.72 Polluted United Kingdom River Eden 15 n.52 0.83 n.5i 0.67 <0.1 0.31 Polluted Leader Water 15 0.77 1.07 0.31 0.71 <0.1 0.24 Unpolluted Oxnam Water 15 0.70 0.85 0.50 0.80 <0.1 Unpolluted Leet Water 15 0.95 0.59 0.42 0.36 <0.1 0.22 Polluted NOTE: Where residues were not detected, the limit of detection was stated. TABLE 13. — Analyses of wildlife samples — heron eggs Number of Mean Mean Mean Residues in mg/ KG Location Eggs in Sample Weight (G) Eggshell Index Pollution Category HCB DiELDRIN DDE PCB'S Netherlands Amsterdam 9 1.2 1.9 7.4 74 Polluted Edam 4 1.0 1.1 1.7 34 Slightly polluted Eenhoorn 8 0.36 0.5 2.8 33 Slightly polluted Stampe Toren 6 0.64 1.5 5.9 34 Slightly polluted United Kingdom Denver 13 52.2 1.49 1.12 6.65 7.3 Very polluted Troy 8 54.0 1.56 0.80 3.17 3.25 Polluted Shieldaig 4 43.1 1.62 <0.03 0.85 <0.5 Unpolluted Druidibeg 4 56.3 0.05 1.35 <0.75 Unpolluted Carrowmore 7 42.3 1.65 0.07 0.41 <0.5 Unpolluted NOTE: Where residues were not detected, the limit of detection was stated. TABLE 14. — Analyses of wildlife samples — common eider eggs Location Number of Eggs in Sample Mean Weight (G) Mean Eggshell Index Mean Residues in mc/kg Pollution DiELDRIN DDE TDE DDT PCB'S He Category Denmark 1970 Hov R^n 10 0.56 9.3 Slightly polluted 1971 Hov R0n lo 0.35 4.4 Slightly polluted Finland Sdderskar 14 101.8 2.16 0.070 1.05 0.08 <0.01 1.8 0.33 Unpolluted Norway Grind0y 12 114.0 2.28 <0.01 0.40 <0.0! <0.01 0.27 Unpolluted NOTE: Where residues were not detected, the hmit of detection was stated. Vol. 7, No. 1, June 1973 49 TABLE 15.— Analyses of wildlif e samplcs- —tern and pelican eggs Number of Eggs in Sample Species Mean Eggsheh Index Mean Residues in mg/kg (fresh weight) Pollution Location HCB DlELDRIN DDE TDE DDT PCBs He Category Canada Balhurst. N.B. 10 Common tern 0.028 0.041 0.91 0.016 0.073 2.36 0.124 Slightly polluted Hamilton. Ont. in Common tern n.83i 2.31 0.76 23.1 n.73 0.49 149 0.87 Polluted Netherlands Wadden See in Sandwich tern 1.13 0.103 0.082 0.51 8.2 1.7 United States South Carolina 10 Royal tern Pelican 1.47 2.28 0.2 0.7 2.8 3.3 0.04 0.7 <0.l 0.6 4.5 4.5 0.8 0.5 Polluted Polluted NOTE: Where residues were not detected, the limit of detection was stated. populations of common terns examined in Canada, from an uncontaminated and a highly contaminated area, showed large differences in all the residues determined, two orders of magnitude in the case of HCB and PCB's. Although the eggshell thickness index of the eggs from the uncontaminated colony (Bathurst) was not determined, the heavily contaminated eggs (Hamil- ton) showed a decrease of 10% as compared with the index of all Canadian eggs measured before 1935. and the shells were mechanically weaker. The reproductive success of the Hamilton colony, as measured by per- centage of fledglings from eggs laid or fledged young per adult pair, was only 16-23% of that of the Bathurst colony, the decrease apparently unlikely to have re- sulted from either the lower density of the colony or disturbance by observers. The high concentrations of some residues found. 2.3 mg/kg for HCB, 23.1 mg/kg for DDE, and 149 mg/ kg for PCB's, were greater than for any other species reported in the study. These values were given on a wet-weight basis, but when expressed on a dry-weight basis to allow for dilTerences in condition, the marked contrast in residue concentrations between the two sites remained. The population of Sandwich terns studied in the Nether- lands was known to have been heavily contaminated by cyclodiene insecticides in earlier years, but telodrin was absent from the 1970 egg sample and dieldrin and endrin were much lower than in 1965. The PCB and mercury contents were higher than in the uncontami- nated Canadian sample of common tern eggs, but much lower than in the contaminated Canadian eggs, and the eggshell thickness index of the Netherlands sample was estimated to have been only about 5% less than in 1950. In the United States, a population of Royal terns was studied, this stock having shown no decrease since 1947. The mean residue levels (except for DDT) were higher than those in the Bathurst colony of common terns from 50 Canada, and not greatly different from those in the Sandwich tern eggs from the Netherlands. By compari- son, the eggs of brown pelicans taken in the same area of the United States had residue concentrations similar to those in the Royal terns, yet the pelican colony has de- clined by over S0% in less than a decade and is now considered in danger of extinction. The eggshell thick- ness index of the pelican eggs has declined by 14% since 1947. CONCLUSIONS (BASED ON WILDLIFE SAMPLES) The results from the wildlife sampling program have emphasized the difficulties involved in selecting ap- propriate species for international monitoring, in ob- taining adequate samples of individuals for analysis, in identifying areas of high contamination, and in relating the residue concentrations found to any measurable biological effect. Despite the detailed manner in which the sampling requirements of the biological program were described, some investigators did not follow these closely. Perhaps the most surprising finding of the biological sampling program was that the differences in residue concentrations between samples of the same species of fish and shellfish from selected unpolluted and polluted areas were often small and. in respect to the combined samples from all countries, not significant. Thus, what may be considered a polluted area in one country could be classified as unpolluted in another, rendering the interpretation of chemical data from a global monitoring program very difficult. Even in the apparently unpolluted areas, where contamination is largely the result of atmospheric fallout or washout or oceanic circulation, the range of values found was considerable for most species examined. Thus, for mussels, PCB concentrations in areas ap- parently free of local pollution ranged from below 0.01 to 0.67 mg/kg. and in herring the DDE concentration; Pesticides Monitoring Journai ranged from less than 0.01 to 0.30 mg/kg. Assuming the level representing background contamination from globally distributed material in the period 1969-71 to be below 0.01 mg/kg, a number of samples taken from areas selected as free of local pollution must nevertheless have had contamination significantly above the baseline level. A much greater number of widely distributed samples would be required to estimate the baseline level of contamination with a satisfactory degree of precision for any one species. TTie information obtained from eggs of piscivorous birds was more limited than that from the fish and shellfish, as few species were sampled by more than one country. Yet the differences between the uncontaminatcd and the contaminated areas, as demonstrated by those species sampled by more than one country, were much larger than was found for fish. Although it was hoped that measurements of eggshell thickness index and reproduc- tive success would help to establish the extent of the effects of such differences, several investigators did not find it possible to complete such measurements. The information supplied does, however, confirm that what may be regarded as a harmful residue level in one species is apparently harmless in another. A 14% de- crease in eggshell thickness index in pelican eggs seems to be a significant ecological factor, as does a 10% decrease in common tern eggs, but the latter was pro- duced by a much higher organochlorine level than occurred in the pelican eggs (although the correlation between organochlorines and eggshell thickness index decrease is only presumptive at the present time). From the results of the chemical exchange sample pro- gram, it is assumed that analytical accuracy is such that the major differences in residue levels found in the wild- life specimens are not due to variations between analysts or analytical techniques. The differences between con- tamination levels in the various populations were often very much larger than those now expected among the group of analysts who participated in the program. Be- fore any international monitoring system is established to assess the level of contamination of the environment and the changes which may follow government action on pollution, closer attention must be paid to the choice of appropriate indicator species and to obtaining adequate numbers of individuals for analysis in a sufficient num- ber of sampling sites. There are very few globally distributed species and probably none ideally suitable for monitoring, but species representing sufficiently large areas would provide adequate information for indicating general trends. The problem of assessing the ecological significance of even the high concentrations found in some populations nevertheless remains a major issue. Unless some measure- ments of appropriate biological parameters can be made in conjunction with the chemical analyses, in both experimental laboratory and field studies, an effective ecological evaluation of chemical data from monitoring programs will be impossible. At the present time, the only practical field measurements which might be cor- related with levels of contamination are those for egg- shell thickness and reproductive success in birds; no comparable information is obtainable for fish popula- tions, yet the residue levels in fish may be important for piscivorous birds, even though they may appear harm- less to the fish themselves. Judgment of the significance of residues in fish can therefore, in some instances, be based on the wider ecological implication of their ultimate effect on the predator species. Further Programs This program has shown that, apart from an improve- ment in the ability of analysts to agree on both the identity and quantity of the major organochlorine resi- dues and an encouraging measure of agreement on mercury residues, the biological sampling and assessment of ecological changes falls far short of that necessary for an effective monitoring program. At the Third O.E.C.D. Technical Conference in Berlin in January 1972, it was emphasized that any further study should be given official support by member governments to ensure that the program would be effectively fulfilled. The O.E.C.D. Sector Group on the Unintended Oc- currence of Chemicals in the Environment, at a meet- ing in Paris in March 1972, endorsed this view and approved a further study with specific objectives of direct interest to member governments. Briefly, the study involves the sampling of populations of herring (or sardine) in the marine environment, perch (or roach) in the freshwater environment, and nestling starlings (Sturmis vulgaris) in the terrestrial environment. Twenty- five individuals of the same age, and as far as possible of uniform sex and size, are to be analyzed individually for organochlorines and mercury. In addition, 10 pike of varying size but of one sex are to be taken from each appropriate location for mercury analysis, using the regression of mercury concentration on weight to cal- culate the mercury content of a 1-kg weight fish. Fish samples are to be taken prior to spawning, and the program will be repeated annually in the same locations for a further 2 years. From this study, an attempt will be made to determine whether a statistically significant decrease in the en- vironmental levels of DDT, PCB"s, or mercury can be found in any of the selected locations, following the action of a number of governments and industries in reducing the usage or discharge to the environment of these chemicals at the present time. It is not antici- VoL. 7, No. 1, June 1973 51 pated that all areas would show a decrease in the period under study, but it is hoped that such a change may be detected in at least some areas. It is clearly desirable that, as far as possible, action by governments and industries to reduce environmental contamination can be shown to be followed in due course by declines in the environ- mental levels of the substances controlled, but the rates of such declines are at present purely speculative. See Appendix for chemical names of compounds discussed in this paper. LITERATURE CITED (1) Holden, A. V. 1970. International cooperative study of organochlorine pesticide residues in terrestrial and aquatic wildlife, 1967/1968. Pestic. Monit. J, 4(3):117- 135. (2) de Faubert Maunder, M. J., H. Egaii. E. W. Godly, E. W. Hammond, ]. Roburn, and J. Thomson. 1964. Clean-up of animal fats and dairy products for the an- alysis of chlorinated pesticide residues. Analyst 89(1056): 168-174, (3) Holden, A. V., and K. Marsden. 1969. Single-stage clean-up of animal tissue e.xtracts for organo-chlorine residue analysis. J. Chromatogr. 44(3-4):481-492. 52 Pesticides Monitoring Journal Pesticide Residues in Natural Fish Populations of the Smoky Hill River of Western Kansas — 1967-69 ' Harold E. Klaassen^ and Ahmed M. Kadoum' ABSTRACT Fish populations from five locations in an area of low pesticide use are described and their pesticide residue levels are given for the 3-year period. 1967-69. The study was carried out in a dry-land farming area with developing irrigation on the Smoky Hill River of west central Kansas. Fish samples were collected by electro-shocking at five sta- tions along an 80-km section of the river. A total of 393 samples of the commonly occurring species (whole body, flesh, gonads) were analyzed for organochlorine residues. During the 3 years, 24 species of fishes were collected: 15 of these species were common in the study area. The number of species, number of individuals collected, and species diversity are presented for each .Nation with respect to time. No endrin, aldrin, or heptachlor residues were detected in any sample. Heptachlor epoxide was found in trace amounts in three samples. Dieldrin was present in 15% of the samples, usually in amounts le.^s than 001 ppm. DDT and its metabolites were detected in 75% of the .samples, usually at only several hundreths of a part per million. The fish populations collected were considered "clean" front pesticides when compared with fishes from other surveys. These data form a baseline for future comparison as the agriculture changes in this area. Introduction Pollution of the environment and its potential effects on the health of man, animals, fish, wildlife, and the ecosystem in general have become subjects of concern. Insecticides have greatly benefited man by reducing disease and increasing food production: they also have been a major source of pollution (/.?). particularly to fish (6, 7). 1 Contribution No. 1149, Division of Biology; No. 1078. Department of Entomology, Kansas Agricultural Experiment Station. Kansas State University, Manhattan. Kans. - Division of Biology. Kansas State University, Manhattan, Kans. 66506. ^ Department of Entomology, Kansas State University, Manhattan, Kans. 66506. Insecticides have been used extensively, and fairly high residue levels have been detected in fish from widely scattered areas i.4,5). A unique opportunity to study the accumulation of pesticide residues and their effect on natural fish populations was provided as the Cedar Bluff Irrigation District, formerly a dry-land farming area with little insecticide usage, developed and as crop pro- duction and insecticide usage intensified (3,10). This study describes the natural fish populations in a segment of the Smoky Hill River in the vicinity of Cedar Bluff Irrigation District, and presents data on pesticide residues in the common species of fishes in the area during the 3-year period. 1967-69. Methods THE STUDY AREA Samples were collected from the Smoky Hill River in Trego and Ellis Counties in west central Kansas (Fig. 1). Typical of the Great Plains Region, the topography is flat to rolling with occasional breaks and canyons. The climate is continental with average annual pre- cipitation of about 54 cm. The Smoky Hill River originates in eastern Colorado and flows eastward forming the major drainage of the northern half of Kansas. Typically, the stream meanders through a wide flat sandy river bed; shore vegetation is generally sparse. The river was interrupted by the con- struction of Cedar Bluff Dam in Trego County in 1951. The reservoir was constructed primarily for irrigation, municipal water, and flood control (//), and at con- servation level extends approximately 15 km upstream. During the course of this study, water from the reservoir was used so extensively for irrigation that none was Vol, 7, No, 1, Iune 1973 53 FIGURE \.—Map of the Smoky Hill River showing the fish sampling sites. Trego and Ellis Counties, west-central Kansas released into the river below the dam. and conditions were relatively stable for some distance below the dam. The entire volume of the river was the result of springs. seepage, local precipitation, and irrigation runoflF below the dam. Stream volume was quite low near the dam. but increased progressively with distance downstream. SAMPLING STATIONS Samples were collected at five locations on the river spanning about 66 km in a straight line or about 80 river km. One station was upstream from Cedar Bluff Reser- voir, and one was just below the reservoir, upstream from the irrigation region. The other three stations were on the river along the irrigation district. Fig. 1 shows the general location of the study area; Table 1 gives locations, the size of the stream at each station, and brief descriptions of the sample stations. Each station was located close to a bridge to facilitate sampling; stations were numbered consecutively down- stream. The stream water was fairly clear except for a few days following rains. Dissolved oxygen usually was near saturation; water temperature typically varied greatly throughout the day; the pH ranged from 7.6 to 8.3, total alkalinity, from 140 ppm to 220 ppm. COLLECTION OF SAMPLES Fish populations were sampled during 1967. 1968. and 1969, using a 230-volt AC, 3,000-watt electro-shocker with two hand-held electrodes. The generator was placed on bridges; a power reel with 110 meters of cord per- mitted sampling that distance from either side of the bridge. To compare fish populations, fish from 91 m (100 yd) of stream were collected by two persons using the hand- held electrodes and dip nets and wading upstream in a zig-zag pattern until fish in the entire 91-m section were collected. The electrodes were held in front of the collectors, and stunned fish were taken in dip nets; care was taken to avoid muddying the water. The same 91-m section was sampled each time at each station. 54 SAMPLES FOR PESTICIDE ANALYSIS Several species of fishes and some specific fish tissues were analyzed for pesticide residues. Whole bodies of four species (stoneroller, red shiner, plains killifish, and green sunfish) were analyzed. These four species repre- sented different trophic levels and were among the most abundant small species in the area, thus most likely subject to predation by larger animals. Knowledge of residue levels in these species would be useful in detect- ing problems of food chain concentration. Attempts were made to collect about 25 fish of each species at each station, but often it was not always possible to collect that many. All species were not collected at all stations. Samples of fish flesh were collected from the most abundant game species, channel catfish, and the two largest species, carp and river carpsucker. These were the ones most likely to be eaten by man; therefore, this tissue was analyzed to detect possible hazards. Attempts were made to obtain flesh from up to 10 individuals per species per station, but frequently this amount could not be collected. Flesh was collected by filleting the fishes and removing the skin from the fillets. Pesticide residues were checked in gonads to detect possible effects on reproduction. To obtain quantities sufficient for analysis, gonads were collected from carp and river carpsucker, the largest species present. At- tempts were made to get gonads from five females and five males from both species at each station during each sampling; it was not possible to collect that quota. Carp usually had sizable gonads most of the year; carpsucker gonads were greatly reduced after mid-summer often making it impossible to get large enough volume for analysis. The samples were partially processed immediately after being collected. The fishes for whole body analysis were individually measured and weighed together and then frozen on dry ice. The fish flesh and gonad samples were taken from fishes that had been weighed and measured. Flesh and gonads of individual fishes were bagged sepa- rately in plastic bags and frozen on dry ice. Pesticides Monitoring Journal TABLE 1. — Description of sampling stations on Smoky Hill River, distance from Cedar Bluff Dam, and the approximate average size of stream Station Description of Sampling Station j Distance from Cedar Bluff Dam Approx. Average Size of Stream AT Normal Low Flow width (m) depth (m) Stream Flow (CMS) (CFS) In Trego County, stream very shallow and open with a sand bottom; no vege- tation on stream's edges because it meandered over a wide river bed of sand through a short grass prairie. In Trego County, stream shallow with sand bottom; small overhanging trees and bushes at edges; some of the bank undercut beneath root masses. In Ellis County, north edge of the stream bordered part way by a bluff and the rest of the edge by sand with a few scattered trees; bottom part sand and part smooth bedrock; some washed out deep spots (about 0.6 m> with sill bottom. In Ellis County, part of stream bor- dered by a bluff; the rest of the edge bordered by gravel or sand with a few small trees; the bottom, sand or gravel with silt in the few deeper holes (1 m) under brush piles. In Ellis County, edges bordered by a few trees with open sand or gravel; bottom with areas of gravel and of sand with a few holes dm) under root masses and brush piles. 30.1 river km upstream (26.1 km straight line) and about 13.5 km from end of reservoir 10.6 river km downstream (7.6 km straight line) 31.0 river km downstream (24.1 km straight line) 36.8 river km downstream (29.0 km straight line) 50.2 river km downstream (40.1 km straight line) 5.5 6.2 10.0 0.06 0.16 0,19 0.17 0.31 0.59 0.65 0.65 23 23 ^ Summerfelt (i4) provides more details on the sampling areas. In the laboratory each sample was thawed and homogen- ized in a blender. For whole-body analysis individuals of one species from one station were pooled to make a sample. The sample of flesh consisted of a pooling of equal weights of flesh taken from each individual of one species to prevent larger fish from biasing the sample. Gonads were treated similarly, keeping sexes separate. After each pooled sample was homogenized, a subsample was taken for residue extraction. RESIDUE EXTRACTION AND ANALYSIS A 10-g subsample was placed in an omni-mixer with 50 ml of redistilled hexane and sufficient anhydrous sodium sulfate to take up the water. The mixture was blended at high speed 1 to 2 minutes. The solution was then decanted through #43 Whatman filter paper into a 100-ml suction flask. The residue was extracted with two additional portions of hexane as described above; extracts were filtered and combined in a suction flask. The container, filter paper, and contents were washed with a final portion (10 ml) of hexane. The total hexane extract was transferred to a round-bottom flask for concentration under vacuum at 35° -40° C to 2-3 ml of hexane. The concentration was transferred quantitatively to a 15-ml centrifuge tube using small portions of hexane totaling 5 ml. An aliquot was used for cleanup and gas chromatographic analysis. Vol. 7, No. 1, June 1973 For the cleanup procedure a silica-gel chromatography microcolumn was prepared by packing a plug of glass wool loosely into a disposable pipet, about 4 cm from the tip, and then adding 1 g of high purity Silica Gel 950 (60-200 mesh). Prior to column chromatography, solvent extract was evaporated to 1 ml. For partial deactivation of silica gel, the 1 ml of concentrated ex- tract used for charging the column was saturated with 5 ^1 of distilled water and transferred quantitatively to the column. It was allowed to percolate through the column at 1-2 ml per minute. The walls of the column were rinsed with small portions of hexane. When the solvent reached the top of the silica gel, elution with the desired eluting solvent was begun. The eluting solvents were 2%, l'7c, and 70% benzene in hexane, 100% benzene and 8% ethylacetate in benzene. The eluate was collected in a 15-ml graduated centrifuge tube. The eluates were concentrated separately to 1 ml, by a stream of nitrogen just before gas chromatography t'8.9). The analyses were performed with RSCO Model it 600 series and Barber-Coleman gas chromatographs, both equipped with electron capture detector. Operating con- ditions were as follows: 55 Column: 6' glass, packed with 3% DC-11 on 60 to 80 mesh silinized Gas Chrom P Temperatures: Column 200° C Detector 220° C Injector 240° C Carrier gas: Nitrogen at a flow rate of 36 ml/min Volume injected: 4 /il of the extract in hexane Each sample was analyzed for these organochlorine pesticides: endrin, aldrin, dieldrin, heptachlor, heptach- lor epoxide, o.p'-DDT, p.p'-DDT, p.p'-DDE, and p.p'- DDD. The analytical procedure was capable of detect- ing residues as low as 0.01 ppm of the above pesticides. Insecticide residues were not corrected for recovery since recovery from fortified samples was essentially 100%. Results and Discussion FISH POPULATION During the 3 years, 24 species of fishes were collected from the 5 stations. Table 2 lists these species along with the percent of times they were taken at each sta- tion, based on the total number of sample collections at each station. The mean and range in number of individuals collected are also presented. The means are expressed as logarithmic means because most samples contained few individuals of a species with an occasional great number. The species names used are accepted common names established by the American Fisheries Society (7). Fifteen species are considered common in the study area: stoneroUer. carp, red shiner, sand shiner, suckermouth minnow, bluntnose minnow, fathead min- now, creek chub, river carpsucker, black bullhead, chan- nel catfish, plains killifish, green sunfish, orangespotted sunfish, and orangethroat darter. All 15 species are rather widely distributed in Kansas (2). The means and ranges of the number of species and species diversity for each station during the 3 years of this study are presented in Table 3. Species diversity was calculated with the following formula which MacArthur and MacArthur (12) applied to diversity in animal populations: Species Diversity = — 2^''. 1" ^t where P, is the portion or fraction of the number of individuals of species , to the total number of individuals of all species collected and InP, is the natural logarithm of that portion. Then the antilog was taken to express the value in a species equivalent. The species diversity index shows the degree of equality distribution of in- dividuals among the different species collected. If exactly the same number of each species was collected, species diversity would equal the number of species. In general, stable communities have high species diversities, and unstable communities or polluted environments have low species diversities. 56 Fig 2 shows the trends of numbers of fish species and species diversities over the 3 years at all stations. The stream conditions at Station 1 varied widely, as re- flected by the erratic pattern of number of species and species diversities. Stations 2 through 5 showed fairly consistent and similar numbers of species and species diversities, indicating a relatively stable situation. PESTICIDE RESIDUES The results of 393 pesticide analyses are given in Table 4 for Stations I through 5, respectively. The data for 1967, 1968, and 1969, were summarized together since residue patterns were generally similar for each of the 3 years. Residues of endrin, aldrin, and heptachlor were not detected in any sample. Dieldrin was detected in a small percentage (15%) of the samples, most of these had only trace «0.001 ppm) amounts. Heptachlor epoxide was detected in only three samples in trace amounts. Resi- dues of DDT and its metabolites were most frequently detected, with DDE being found in most samples and the other compounds found in only a few samples. In most cases, residue amounts were very low, several hundredths of a part per million. Biological magnification was not shown in the whole body analysis of small species, since no trend with respect to trophic level of fish species was evident. Residues were low, and these species did not appear to pose a threat to larger predators. Residues in edible flesh samples were at very low levels, the highest being 1.66 ppm DDE in one sample of channel catfish meat. All samples were considered safe for human consumption, being well below the FDA tolerance levels. The gonads tended to have the most residues, especially carp testes. Whether or not residues in gonads affected the reproductive success is unknown. Fish populations appeared to be consistent throughout the study with young of all the common species consistently appearing in collections. Our results compared with those of the National Pesti- cides Monitoring Program indicate that pesticide resi- dues in fishes of the Smoky Hill River region are among the lowest in the Nation. Henderson et al. (4.5) showed DDT and its metabolites in 99 ff of the samples at levels up to 45 ppm for 1967 and lOOCJ for 1969 with levels up to 57.8 ppm. Seventy-five percent of all our samples had DDT and its metabolites with 0.10 ppm the highest for whole body. 1.66 ppm the highest (second highest was 0.11 ppm) for flesh, and 1.96 ppm the highest (second highest was 0.61 ppm) for gonads. The whole Pesticides Monitoring Journal TABLE 2. — The logarithmic mean and range (in parenthesis) of numbers of fishes collected per sampling and the percent of times that each species was collected during 1967, 1968, and 1969 Species Gizzard shad Stoneroller Carp Plains minnow Red shiner Sand shiner Suckermouth minnow Bluntnose minnow Flathead minnow Creek chub River carpsucker Black bullhead Yellow bullhead Channel catfish Stonecat Flathead catfish Plains killifish White bass Green sunfish Orangespotted sunfish Blue gill Largemouth bass Orangethroat darter Freshwater drum Number of sampling periods Station 1 Mean AND Range ( ) 0.1 (0-2) 4.0 (0-38) 2.9 (0-96) 0.9 (0-43) 3.2 (0-250) 14.9 (0-662) 0.4 (0-12) (0-32) 0.3 (0-3) 6.1 (0-323) 0.4 (0-10) 171,1 (22-2493 ) 0.4 (0-7) 0.3 (0-2) 0.1 (0-1) 0.4 (0-5) Percent Times Collected 82 45 82 27 100 27 Station 2 Mean AND Range ( ) 0.03 (O-n 51.4 (1-354) 1.7 (0-10) 0.2 (0-2) 142.5 (25-498) 133.6 (25-460) 1.6 (0-54) 46.1 (7-337) 17.6 (1-70) 13.4 (3-65) 0.8 (0-9) 2.2 (0-9) 0.1 (0-2) 1.4 (0-8) 0.1 (0-1) 43.4 (7-204) 42.8 (10-89) 0.9 (0-7) 0.1 (0-1) 0.4 (0-5) 1.3 (0-17) 0.03 (0-1) Percent Times Collected 100 100 52 100 100 100 33 100 0 100 52 19 33 Station 3 Mean AND Range ( ) 0.1 (0-1) 43.1 (3-182) 2.3 (0-21) 93.7 (16-528) 125.1 (5-634) 0.4 (0-4) 98.6 ( 14-363 ) 34,0 (3-314) 8.4 (2-89) 2.0 (0-61 ) 1.4 (0-18) 0.04 (O-I) 2.5 (0-26) 0.04 (0-1) 0,1 (0-1) 20,6 (0-226) 15.0 (0-75 ) 3.3 (0-24) O.I (0-1 ) 0,5 (0-10) 0.3 (0-3) Percent Times Collected 100 100 25 100 100 45 10 95 Station 4 Mean and Range ( ) 20 0,1 (0-7) 179,7 (33-1678) (0-24) 0.04 (0-1) 292.4 (76-1461) 267,5 (60-1617) 17,9 (0-139) 163.1 (18-1129) 41.5 (6-421 ) 8.0 (0-30) 1.5 (0-27 ) 0.5 (0-2) 0.04 (O-n 1.5 (0-61) 1.4 (0-7) 0.4 (0-4) 86.5 (23-452) 18.9 (3-100) 3.4 (0-29) 0.2 (0-3) 7.1 (0-251 ) 0.1 (0-2) Percent Times (Collected 65 30 100 Station 5 Mean and Range ( ) 100 86,5 (9-341) 65 0,3 (0-7) 5 0.1 (0-1) 100 159.0 (47-290) 100 138.5 (23-586) 90 34.0 (7-137) 100 15.8 (3-63) 100 3.8 (0-57) 95 4.4 (0-31) 45 1.0 (0-13) 50 0.3 (0-5) 2.4 (0-22) 0.9 (0-11) 0.2 (0-1) 50.9 (2-453) 5.4 <0-26) 0.7 (0-6) 0.3 (O-I) (0-9) 0.2 (0-2) Percent Times Collected 12 100 100 100 100 83 8 58 17 0 25 50 25 100 50 0 33 83 17 Vol. 7, No. 1, June 1973 57 TABLE 3. — Mean number of species and species diversity of fishes collected per sampling station in the Smoky Hill River during 1967, 1968, and 1969 Station 1 2 3 4 5 Mean number of species collected 7.0 1.1.1 12.8 14.4 12.8 Range in number of species collected 1-12 10-17 9-17 9-18 8-16 Mean species diversity 2.55 6.56 6.55 6.33 5.40 Range in species diversity 1.00-4.44 5.18-7.92 3.23-8.56 4.01-8.46 3.44-6.74 Number of samplmg periods II 21 20 20 12 body results for dieldrin residues by Henderson et al. (4,5) for 1967-68 showed residues in 75% of the samples with values up to nearly 2 ppm. During 1969 they found dieldrin in 93% of the samples with levels up to 1.59 ppm. We detected dieldrin in only 15% of all our samples with highest values in the whole bodies 0.04 ppm, in the flesh 0.01 ppm, and in the gonads 0.08 ppm. Results of this study indicate that fish populations in the Smoky Hill River of western Kansas are relatively "clean" of pesticide residues. This is undoubtedly be- cause of the low pesticide use in this area of traditional dry-land farming. These data form a baseline with which future studies of the fish populations and residue levels can be compared. Sec Appendix for chemical names of compounds discussed in this paper. This study was supported in part by funds from Regional Research Project. NC-85. "Reduction of Hazards Associated with the Presence of Residues of Insecticidal Chemicals in the Environment," Kansas Agricultural Eperimen Station, Project 481, Kansas State University. Station 1 Station 20 I 5 I 0 5 0 I 5 I 0 5 0 I 5 I 0 5 0 I 5 I 0 5 0 I S Station I Q 5 s Station 3 Station 4 1 1 — I — I 1 — I 1 1 — I 1 I J FMAMJ JASOND — t — I — I — 1 — I — I — I — I — I — 1 — I — I — I — I — 1 — I — I — I .11 J FMAMJ JASON DJ FMAMJ J AS . . KG SPECIES , . SPECIES DIVERSITY T 1 1 1 1 1 1 1 1 1 I I I I I I I I ' f \y -T 1 1 1 1 1 1 1 I I T" . /^\ -I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I T -1 1 1 1 1 1 1 I I T" \ y -T 1 1 1 1 1 T 1 — I — I — 1 — I — I — r- -1 — I — I — I — I — 1 — I — I I r" -1 — I — I — I — I — I — I — I — r 1 — 1 — I — I — I — I — 1 — r- — I — I — I — I — I — I — I — I — r— 1 — r— J FMAMJ JASOND 19 6 7 JF M AM J JASON DJ FMAMJ JAS 19 6 8 19 69 FIGURE 2 —The number of species of fishes collected and species diversity for each sampling period al the five stations during the study. 1967-69 58 Pesticides Monitoring Journai TABLE 4. — Pesticide residues in fish and fish tissues from the Smoky Hill River, Kansas — 1967-69 (T = <0.01 PPM] Tissues Number of Samples > Number of Times Detected and Range ( ) in ppm OF Detected Residues =' DiELDRIN Heptachlob bPOXlDE o,p- DDT P.P- DDT STATION 1 STATION 2 STATION 3 P.P- DDE P.P- DDD StoneroUer Whole body 1 0 0 n 0 1 (.02) 0 Plains killilish Whole body 2 n n 1 (.01 ) 1 (.02) 2 (.01-.02) 0 Carp Flesh 2 0 0 ft ft 1 (.01) 0 River carpsucker Flesh 1 n n n ft 0 0 Channel catfish Flesh 1 n 0 " 0 1 (1.66) 0 Carp Testes 2 (1 n n n 2 (.02-1.96) 0 Ovaries : 0 n n ft 2 ( .04-.06) 0 StoneroUer Whole body 14 1 (T) ft ft ft 11 IT-.03) 0 Red shiner Whole body !5 1 (T) 1 (T) ft 1 (.01) 15 (T-.05) ft Plains kiUifish Whole body Q ft ft ft 0 4 (.01-.02) 0 Green sunfish Whole body 18 J (T) 0 ft ft 15 (.01-.04) 0 Carp Flesh 10 1 (T) ft ft ft 8 (T-.04) n River carpsucker Flesh •I ft ft 1 (.01) ft 2 (T-.04) ft Channel catfish Flesh 6 0 0 1 (.ftl ) ft 5 (.01-.04) 1 (.03) Carp Testes 12 1 f.08) ft ft ft 10 (.01-.58) 1 (.03) Ovaries 9 ft ft ft 1 (.01) 5 (.01-.03) 0 River carpsucker Ovaries 1 ft ft ft 0 1 (.03) 0 StoneroUer Whole body 14 (.01 1 ft ft ft II (T-.04) 0 Red shiner Whole body 14 2 (T) ft n 1 (.01) 11 (T-.07) 1 (.02) Plains killifish Whole body S 0 ft 0 0 4 (T-.Ol) 0 Vol. 7, No. 1, June 1973 59 TABLE 4.— Pesticide residues in fish and fish tissues from the Smoky Hill River, Kansas— 1967-69— Continued [T = <0.01 PPM] Tissue Number op Samples ' Number of Times Detected and Range ( ) in ppm of Detected Residues -■"■ DiELDRIN Heptachlor Epoxide o.p- DDT p.p- DDT STATION 3— Continued STATION 4 StoneroUer Whole body 14 2 (T) 0 0 Red shiner Whole body 14 6 (T-.04) 0 n Plains kilUfish Whole body 10 1 (T) 0 0 Green sunfish Whole body 15 2 (T) 0 0 Carp Flesh 13 1 (T) 0 0 River carpsucker Flesh 9 2 (T) 1 (T) 0 Channel catfish Flesh 10 1 (T) 0 0 Carp Testes 14 1 f.on 0 0 Ovaries 12 1 (T) 0 n River carpsucker Testes 2 2 (.01-.02) n n Ovaries 7 1 (T) 0 0 STATION 5 p.p- DDE (T-.04) 12 (T-.08) 7 (T-.02) 11 (.01-.04) 9 (.01-.03) 7 (T-.Ol) 6 (T-.Ol) 14 (T-.08) 10 (T-.03) 2 (.01-.03) 3 (T-.Ol) P.P- DDD Green sunfish Whole body 14 2 (T) 1 (T) 0 0 13 (T-.04) 0 Caip Flesh 12 2 (T-.Ol) 0 0 0 8 (T-.03) 0 River carpsucker Flesh 6 1 (T) 0 1 (.04) 0 2 (T-.Ol) 0 Channel catfish Flesh 9 (T) n 0 1 (.01) 6 {.01-.02) 0 Carp Testes 14 5 (T-.Ol) 0 0 1 (.01) 14 (T-.14) 0 Ovaries 13 2 (T) 0 0 0 8 (T-.Ol) 1 (.01) River carpsucker Testes 3 2 (T-.Ol ) 0 0 0 2 (.01-.02) 0 Ovaries 5 0 0 0 0 1 (.01) 0 (.01) 0 0 1 (.01) 0 0 0 (.01) 1 (.01) StoneroUer Whole body 4 (T-.03 ) 0 0 n n 8 (T-.09) 0 Red shiner Whole body 2 6 1 1 n n n 8 (.01-.04) 0 Plains killifish Whole body 4 4 I n 0 n n 4 (T-.Ol) 0 Green sunfish Whole body 1 1 1 1 0 0 1 (.02) 5 (T-.03) 0 Carp Flesh R 3 0 1 (.07) 0 2 (.01) 0 60 Pesticides Monitoring Journal TABLE 4. — Pesticide residues in fish and fish tissues from the Smoky Hill River. Kansas — 1967-69 — Continued [T --- <0.01 ppMl Tissue Number of Samples ' Number of Times Detected and Range ( ) in ppm of Detected Residues =■■"■ Dieldrin Heptachlor Epoxide o,p- DDT P.P- DDT STATION 5— Cominued P.P- DDE P.P- DDD River carpsucker Flesh (T-.Ol) (T) 0 n n 1 (.01) 0 Channel catfish Flesh <) 3 (T) 0 1 (.07) 0 5 (T-.02) 1 (.02) Carp Testes (T-.Ol) (T) 0 0 0 4 (.01-.07) 0 Ovaries 7 1 0 0 n 3 (.01-.02) 0 River carpsucker Testes (T) (T) n 0 0 1 (.01) 0 Ovaries 6 (T) 0 0 0 1 (.01) 0 1 For whole body analysis, individuals of one species from one station were pooled to make one sample. The sample of flesh consisted of a pooling of equal weights of flesh taken from each individual of one species: gonads were treated similarly, keeping sexes separate. 2 Wet-weight basis. 3 Endrin, aldrin, and heptachlor residues were all zero values. LITERATURE CITED (1) Bailey. R. M., J. E. Fitch. E. S. Herald. E. A. Lachner. C. C. Lindsey. C. R. Rnhins. ami W . B. Scott. 1970. A list of common and scientific names of fishes from the United States and Canada, 3rd ed. Special Publ. No. 6. Am. Fish. Soc. 149 pp. (2) Cross, F. B. 1967. Handbook of fishes of Kansas. Misc. Publ. No. 45, Museum of Natural History, Univ. of Kans., Lawrence. Kans. 357 pp. (3) Harvey, T. L., H. Knulson. T. L. Hopkins, and (i. F. Swoyer. 1971. Pesticide use patterns in a west-central Kansas irrigation district. Kans. Agric. Exp. Stn. Rep. of Progress, March 1971, 14 pp. (4) Henderson, C. A. Inglis, and W . L. Johnson. 1971. Organochlorine insecticide residues in fish — fall 1969 (National Pesticides Monitoring Program). Pestic. Monit. J. 5(1):1-11. (5) Henderson, C, W. L. Johnson, and A. Inglis. 1969. Organochlorine insecticide residues in fish (National Pesticide Monitoring Program). Pestic. Monit. J. 3(3): 145-171. (6) Inglis. A.. C. Henderson, and W . L. Johnson. 1971. Expanded program for pesticide monitoring of fish. Pestic. Monit. J. 5(l):47-49. (7) Johnson. D. W. 1968. Pesticides and fishes — a review of selected literature. Trans. Am. Fish. Soc. 97(4):398-424. (8) Kadoum. A. M. 1967. A rapid micromethod of sample cleanup for gas chromatographic analysis of insecticidal residues in plant, animal, soil, and surface and ground water extracts. Bull. Environ. Contam. Toxicol. 2(5): 264-273. (9) Kadoum, A. M. 1968. Application of the rapid micro- method of sample cleanup for gas chromatographic analysis of common organic pesticides in ground water, soil, plant and animal extract. Bull. Environ. Contam. Toxicol. 3(2):65-70. {10) Knutson. H., A. M. Kadoum. T. L. Hopkins. G. F. Swoyer. and T. L. Harvey. 1971. Insecticide usage and residues in a newly developed Great Plains irrigation district. Pestic. Monit. J. 5(1): 17-27. (//) Koch. D. L. 1968. Some limnological characteristics of Cedar Bluff Reservoir, Trego County, Kansas, Master's thesis. Ft. Hays Kansas State College, Hays, Kans. (12) MacArthur. R. H.. and J. W. MacArthur. 1961. On bird species diversity. Ecology 42(3):594-598. (13) Moats, S. A., and W. A. Moats. 1970. Toward safer use of pesticides. Bioscience 20(8):459-464. (14) Summerfelt, R. C. 1967. Fishes of the Smoky Hill River, Kansas. Trans, Kans. Acad. Sci. 70(1): 102- 139. Vol. 1, No. 1, June 1973 61 Organochlorine Pesticides and Polychlorinated Biphenyls in Black Duck Eggs From the United States and Canada — 1971 ' Jerry R. Longcore and Bernard M. Mulhem ABSTRACT Black duck (Anas rubiipcs) e^gs were collected in 1971 from the Northeastern United States and Canada. All 61 eggs analyzed contained DDE residues: the mean DDE residues for States and Provinces ranged from 0.09 to 5.94 ppm on a wet-weight basis, with mean concentrations exceeding 1.0 ppm in eggs from Maine. NeM- York. New Jersey, and Delaware. The highest DDE concentration, 14.0 ppm, was in an egg from Delaware. DDD and DDT residues averaged ' Method, No. As-3. 5 p. i4) Fernandez, F. J., and D. C. Manning. 1971. The determination of arsenic at sub-microgram levels by atomic absorption spectrophotometry. At. Absorpt. Newsletter 10(4);86-88. (5) Manning. D. C. 1971. A high sensivity arsenic-selenium sampling system for atomic absorption spectroscopy. At. Absorpt. Newletter 10(6): 12.3-124. (6) Kuwata. K., K. Hisatomic. and T. Ha.'/cgawa. 1971. The rapid determination of trace amounts of cadmium and copper in river and sea water by atomic absorption spectroscopy. At. Absorpt. Newsletter 10(5):1 1 1-1 15. i7i Wishart. W. 1971. A mercury problem in Alberta game birds. Department of Lands and Forests. Alberta, Canada. 10 pp. (HI Schroeder. H. A.. P. Nason. I. H. Tipton, and J. Balassa. 1967. Essential trace metals in man: zinc, re- lation to environmental cadmium. J. Chron. Dis. 20: 179-210. (9) Schroeder, H. A., and J. J. Balassa. 1961. Abnormal trace metals in man: cadmium. J. Chron. Dis. 14:238- 256. 1 10) Wiersma. C, . B.. H. Tai. and P. F. Sand. 1972. Pesticide residues in soil from eight cities — 1969. Pestic. Monit. J. 6(2):126-129. 111) Ehman, P. J. 1972. Review of developments with the organic arsenicals. The Ansul Company, Marinette. Wisconsin. 1972. 4 p. 72 Pesticides Monitoring Journal PESTICIDES IN WATER Pesticides in Selected Western Streams — 1968-71 ' Jean A. Schulze, Douglas B. Manigold. and Freeman L. Andrews ABSTRACT This paper presents data from the U.S. Geological Surrey program for moniloriiif; pesticides in lite streams of the Western United States for the period October 1968 to Sep- tember 1971. Data for the previous 3 years of the study were published in earlier issues of the Pesticides Monitorittg Journal (3. 8). Compounds determined include the common chlorinated insecticides and herbicides. Heptachlor and its epo.xide were not detected during the 3-year period, and aldrin was found only once. DDT was the most frequently occurring insecti- cide, and 2,4,5-T tlie most common herbicide. The amounts observed were small: the maximum concentration of an insecticide was 0.46 ixg/litcr for DDT. and of an herbicide 0.99 iig/liter for 2.4-D. Concentrations were highest in water samples containing appreciable amounts of suspended sediments. Graphs arc included to show insecticide and herbicide occurrences for the 4-year period (October 1967- Septemhcr 1971) during which all 20 monitoring stations have been in operation. Beginning in July 1970. the phosphorothioate insecticides — parathion. methyl parathion, malathion, and diazinon — were determined monthly on all samples. Malathion was not found during this period. Polychlorinated hiphenyl (PCB's) compounds which were monitored for beginning in October 1969 were also detected at two stations. Introduction Data from the U.S. Geological Survey's pesticide Tionitoring program for the Western United States have leen previously reported in this Journal {3.H). This paper 3resents data collected from October 1968 through September 1971 for the same 20 stations. The pesticides Tionitored include the chlorinated insecticides and her- Watcr Resources Division. U.S. Geological Survey, U.S. Departmenl of the Inlerior, Austin. Tex. 78701. (Publication authorized by the Director. U.S. Geological Survey.) Vol. 7, No. 1, June 1973 bicides previously reported, as well as chlordane and toxaphene. From January to June 1970. samples were analyzed quarterly for the phosphorus insecticides — methyl parathion. parathion, and diazinon. Beginning in July 1970. the samples were analyzed monthly for these compounds and also for malathion. Beginning in October 1969. the samples were analyzed routinely for polychlo- rinated biphenyl (PCB's) compounds. Data Collection Sites Each of the 20 sampling stations is a designated or operated U.S. Geological Survey irrigation-network location where inorganic water-quality and stream- discharge data are available. These stations are listed in Table 1 and their locations are shown in Fig. 1. His- torical hydrologic and inorganic data for all 20 stations are available from U.S. Geological Survey offices in the respective States. Sampling Procedures Samples were collected in 1 -quart Boston round glass bottles sealed with a Teflon-lined screw cap. These narrow-mouth bottles made possible the collection of depth-integrated samples. Two bottles were collected at each station; the contents of one was used for in- secticide analysis and the other for herbicide analysis. A duo-pak container, consisting of a form-fitting ex- panded polystyrene ca.se placed in a corrugated card- board carton, was used for mailing the samples and for protecting the bottles from frost, light, and shock. The package is compact and light weight, and very little breakage occurred. The samples were transported by 73 TABLE 1. — Pesticide-monitoring stations in Western United Stales Geolooical Survey Station Number 6-2145 6-4760 6-7660 6-8070 7-1305 7-2450 7-2505 8-1140 8-1620 8-3965 8-4692 9-3150 9-5180 9-5255 10-3350 1 1-4070 11-4255 12-5105 13-1545 14-1057 Stream and Location Yellowstone River near Billings, Mont. James River at Huron. S. Dak. Platte River at Brady, Nebr. Missouri River at Nebraska City. Nebr. Arkansas River below Jolin Martin Reservoir, Colo. Canadian River near Wliitefield, Okla. Arkansas River at Van Buren, Ark. Brazos River at Richmond, Tex. Colorado River at Wharton, Tex. Pecos River near Aitesia, N. Mex. Rio Grande below Anzalduas Dam. Tex. Green River at Green River, Utah Gila River below Gillespie Dam, Ariz. Colorado River (Yuma Main Canal) below Colorado River Siphon, at Yuma, Ariz. Humboldt River near Rye Patch, Nev. Feather River near Oroville, Calif Sacramento River at Verona, Calif. Yakima River at Kiona, Wash. Snake River at King Hill, Idaho Columbia River at The Dalles, Oreg. Pesticide Analysis Started (Date) 10-11-67 10-31-67 10-18-67 10-18-65 10-16-65 12-13-67 10-21-65 2-01-66 10-22-65 11-02-67 10-15-65 11-22-67 11-21-57 10-12-65 10-17-67 10-31-67 11-29-65 10-11-65 10-17-65 10-27-65 airmail because herbicides, particularly 2,4-D, can de- compose quite rapidly (4). The average time from sampling to receipt of the sample at the laboratory was 3 days. Analytical Procedures Analytical procedures were essentially the same as pre- viously reported (8). Upon receipt of the sample, one bottle was designated for insecticide analysis and the other for herbicide analysis. The herbicide sample was acidified, and the bottles were then refrigerated until ex- traction was begun. No attempt was made to separate suspended sediment from the water for a separate analysis. Insecticide samples were analyzed, together with a reagent blank, by the U.S. Geological Survey method described by Goerlitz and Brown (6) and summarized below. The entire sample (800-900 ml) was extracted with redistilled hexane and the extracts dried over anhydrous sodium sulfate before concentration to 2 ml in a Kuderna-Danish concentrator. From January to July 1970, samples were checked quarterly for several phosphorus pesticides using electron-capture detectors. Beginning in July 1970. a Tracor flame photometric detector was used in the phosphorus mode (526 nm filter) to screen the extracts prior to cleanup. The flame- 74 photometric detector was mounted on a MicroTek 220 equipped with two ¥■*" X 6' pyrex columns packed with 3% OV-1 and 5% OV-210 as described by Bow- man and Beroza (2). After analysis for the phosphorothioate compounds, alumina cleanup, as described by Law and Goerlitz (7), was used before electron capture analysis. Occasional sulfur interference was eliminated by adding metallic mercury (5). Chlorinated insecticides were analyzed on both a Varian Model 200 dual-column chromatograph and a MicroTek Model 160. The columns used in the Varian instrument were Vs" X 5' pyrex. One was packed with 3^r OV-101 and the other with a mixed column made up of equal weights of 3'7r OV-1 and 5% OV- 210 both on 100/120 mesh Gas Chrom Q. The V^" X 5' pyrex column in the MicroTek instalment was packed with the mixed OV-1 /OV-210 phase. Any pesticides suspected on one column were confirmed on the other column prior to reporting. When PCB compounds were suspected, they were verified by their elution pattern on an alumina cleanup column and the peak ratios were compared with a standard of the suspected compound to determine the presence or ab- sence of the DDT family. After January 1971. the silicic acid cleanup method of Armour and Burke (/) was used on each sample suspected of containing PCB's. Recovery data, as determined by extracting distilled water to which acetone solutions of insecticides had been added, ranged from 85 to llO''/r. No recovery correc- tions were made because most of the values reported were slightly above the lower detection limits of 0.005 /ig/ liter for most of the chlorinated compounds: chlor- dane was detectable to about 0.1 /ig/liter. and toxaphene to 0.5 to 1.0 Mg/liter. The phosphorus compounds could be determined to 0.01 Mg/Mter. Herbicide samples were analyzed in sets of eight, along with a reagent blank, according to the method described < by Goerlitz and Brown (6). Each acidified sample (800- 900 ml) was extracted with redistilled ethyl ether. The extract was saponified using potassium hydroxide, and this basic solution was subjected to a cleanup extraction using ether to remove organic contamination which may have been present in the original sample. After the cleanup extraction, the solution was acidified and the phenoxy acid herbicides were extracted with ether. This extract was allowed to dry over acid sodium sulfate, the ether evaporated, and the herbicides esterified with boron trifiuoride-methanol reagent. After esterification. the samples were passed through a Florisil cleanup column, and the herbicide methyl esters eluted with benzene to a final volume of 2.0 ml. Herbi- Pesticides Monitoring Journal 6|l 50"—. J. 103 • a-iuQ Pesticide station in operation, 1965-71 • 8-3965 Pesticide station in operation, 1967-71 FIGURE I . — Pcsticide-moniioring stations in Western United Stales cide methyl esters were analyzed on a dual-column Varian Model 200 chromatograph. One column was packed with 97c DC-200 and 1 9r Carbowax 20M on 60/80 mesh Gas Chrom Q and the other column was packed with 10% QF-1 and 0.5^'r Carbowax 20M on 60/80 mesh Chromosorh W. Herbicide concentrations could be routinely determined as low as 0.005 Aig/liter in most waters, with the excep- tion of 2,4-D which was detectable to a level of 0.02 /ig/jiter. Spiked samples were used to check the entire extraction and cleanup procedures and recovery ranged from 85 to 110%. No corrections for recovery were made. Discussion of Results Results of analyses of water samples for the 3-year period — October 1968 to September 1971 — are given in Table 2; the number of occurrences at each station of pesticides analyzed for during this entire period are given in Table 3. Heptachlor and its epoxide were not detected and aldrin was found only once during the 3- year period. Samples from Yellowstone River near Billings. Mont., contained no insecticides. Six other streams were posi- tive only once for the chlorinated insecticides, and five of these six streams showed no phosphorus compounds Vol. 1, No. 1, June 1973 75 during the final year. Pesticide concentrations were never in excess of the permissible limits established for public water supplies by the National Technical Ad- visory Committee to the Secretary of the Interior (9), although in several instances concentrations were meas- ured that were above the environmental levels of 0.05 Mg/liter recommended for marine or estuarine waters. The highest concentration of insecticide observed was 0.46 /ig/ liter DDT in the November 1968 sample from Pecos River near Artesia, N. Mex., the allowable limit for DDT in public drinking-water supplies is 42 /ig/liter. It should be noted that 36% of all insecticide occurrences and 33% of the occurrences of the DDT family insec- ticides were at one site: Gila River at Gillespie Dam, Ariz. The occurrences of the three phcnoxy acid herbicides for all 20 stations by year for the period October 1967 to September 1971 are shown in Fig. 3. Total occurrences reached a peak of 106 during 1968-69 and declined sharply to 54 during 1970-71. This decrease of about 50%' was due to reduced occurrences of 2.4-D and 2,4,5-T. Every station had occurrences of herbicides, but Green River at Green River, Utah, had only one occurrence. The highest concentration of herbicide found was 0.99 Mg/ liter of 2,4-D in the sample from Feather River near Oroville, Calif., in December 1969. The established criteria permit 100 ^g/ liter of the three herbicides com- bined in public drinking water supplies. The total occurrences of chlorinated insecticides with the occurrence of DDT and its metabolites. DDD and DDE, for the period October 1967 lo September 1971 are compared in Fig. 2. The data show that total occur- rences of insecticides have declined since 1968 (Fig. 2). Occurrences of the DDT family of insecticides also de- creased, and the ratio between the DDT family and all insecticides declined from 82% in 1968 to 65%- in 1971. 175 75 - 25 - n All insecticides (82%) Q °DT family FIGURE 2. — Occurrences of chlorinated insecticides hv vear, October 1967 to September 1971 76 Silvex occurrences did not change significantly over the 4-year period, and of the total silvex occurrences. 64% were detected at one station — Humboldt River near Rye Patch, Nev. Of the total 2,4,5-T occurrences, 47% were detected at two stations — Arkansas River at Van Buren, Ark., and Canadian River near Whitefield, Okla. The Canadian River is a tributary of the Arkansas River approximately 88 river miles upstream from the Van Buren site. See Appendix for cliemical names of compounds discussed in this paper. LITERATURE CITED f/) Armour. ./. A., and Jerry A. Burke. 1970. Method for' separating polychlorinated biphenyls from DDT and its • analogs. J. Assoc. Off. Anal. Chem. 53(4):76 1-768. (2} Bowman. M. C. and Morton Beroza. 1970. GLC reten- tion times of pesticides and metabolites containing i phosphonis and sulfur on four thermally stable columns. J. Assoc. Off. Anal. Chem. 53(3):499-508. (.■?) Brown. £.. and Y. A. Nishioka. 1967. Pesticides in selected western streams — a contribution to the national ' program. Pestic. Monit. .1. U2):38-46. (4) GocrUtz. Donald F.. and William L. Lamar. 1967. De- icrmination of phenoxy acid herbicides in water by elec- tron-capture and microcoulometric gas chromatography. U.S. Geol. Survey Water-Supply Paper 1817-C, 21 p. f5) GocrUtz. Donald F.. and LeRoy M. Law. 1971. Note on removal of sulfur interferences from sediment extracts . for pesticide analysis. Bull. Environ. Contam. Toxicol. f>(l);9-10. 16) GocrUtz, Donald /•'., and Eugene Brown. 1972. Methods for analysis of organic substances in water: U.S. Geol. Survey Techniques Water Resources Inv., Bo O ^ CD ^ cn r- ^ to CTi to o> 1430 352 07/07/71 •■> 1615 369 08/10/7! ' 1300 261 01 (DDE) 09/09/71 = 0930 59 ,04 (2,4-D) USGS NO . 7-2505 ARKANS/ iS RIVER AT VAN BUREN , ARK. (Beginninp Decembe r 1970, sar nples collected at Lock and Dam 13, below Fo rt Smith. Ark.) 10/15/68 1035 9190 .01 (DDT) 11/14/68 1335 15400 12/18/68 1135 31300 .03 (2,4,5-T) 01/07/69 — 48300 .08 (DDD); .08 (2,4-D); ,05 ( 2,4,5-T) 02/10/69 1500 54500 ,11 (2,4-D); .06 (2,4,5-T) 03/19 69 1130 23000 04/10/69 1120 50400 05/08/69 1020 77800 .02 (2,4,5-T) 06/10/69 1010 59700 .07 (2,4-D); .07 (2,4,5-Tl 07/16/69 0952 32300 .04 (2,4,5-T) 08/14/69 0830 18600 .03 (2,4,5-T) 09/17/69 1000 15800 .02 (2,4,5-T) 10/14/69 0830 57100 .01 (DDD); .02 (DDT); .01 (Lindane); .05 (2,4,5-T) 11/20/69 1205 16800 .02 (2,4,5-T) 12/16'69 1335 8900 01/23/70 1355 14600 .01 (DDD); .09 (DDT) 02/17/70 1405 6140 .05 (DDT); .01 (2,4,5-T) 03/13'7O = 0945 17600 04/17/70 1245 53100 .01 (DDT); .01 (Dieldrin); .03 (2,4-D); .02 (2,4,5-T) 06/17/70 1425 43600 .06 (2,4-D); .06 (2,4,5-T) 07/17/70 -■ 1500 14600 .01 (DDE); .05 (DDT); .02 ( 2,4,5-T) 08/17/70 ■■ 0905 1570 .06 (DDT); .02 (2,4,5-T); .07 (Diazinon) 09/18/70•■ 1010 16000 .02 (2,4,5-T) 10/13/70 •' 1335 44400 .05 (DDT); .06 (2,4,5-T) 1 1/18/70 ■•' 1000 17900 .01 (DDT) Vol. 7, No. 1, J UNE 197 3 Instan- Time taneous Date (24 Dis- Residues in / 0830 9450 .02 (2,4,5-T) 10/01/71 = 0900 15900 .03 (2,4,5-T) USGS NO. 7-2450 CANADIAN RIVER NEAR WHITEFIELD, OKLA. 10/22/68 0715 800 .04 (Silvex); .05 (2,4,5-T) 11/19/68 0750 410 .15 (2,4-D); .05 (2,4,5-T) 12/19/68 0815 885 .03 (2,4,5-T) 01/22/69 1030 506 .02 (DDD); .15 (2,4-D); .09 (2,4,5-T) 02/27/69 1700 24100 .04 (2,4,5-T) 03/25/69 1500 13200 .04 (2,4,5-T) 04/30/69 0715 14700 .05 (2,4,5-T) 05/15/69 0750 5600 .04 (2,4,5-T) 06/19/69 0710 634 .04 (2,4,5-T) 07/25/69 1330 398 .03 (2,4,5-T) 08/27/69 1420 793 .01 (DDT); .03 (2,4,5-T) 09/25/69 < 1400 156 10/30/69 1425 964 .02 (2,4,5-T) 11/26/69 1430 12100 .03 (2,4,5-T) 12/16/69 1300 7320 02/26/70 ■-■ IIOO 370 .04 (2,4,5-T) 03/24/70 = 1130 374 .01 (DDT); .02 (2,4,.5-T) 04/21/70 = 1130 426 .03 (2,4,5-T) 05/27/70 = 1300 1230 .02 (2,4,5-T) 06/25/70 1200 2840 .03 (2,4,5-T) 07/29/70 = 1045 410 .03 (2,4,5-T) 08/27/70 ' 1330 1430 .03 (2,4,5-T) 09/29/70 = 1100 68 .01 (2,4,5-T) 11/30/70 3 1100 3230 12/22/70 ■-• 1400 8000 .02 (2.4,5-T) 01/20/71 - 1435 I06CK> .03 (2,4,5-T) 02/02/71 ■■■ 1500 7530 .01 (Lindane); ,02 (2,4,5-T) 03/17/71 ■■ 1430 6480 01 (Lindane) 04/20/71 ■' 1400 6180 .01 (2,4,5-T); .01 (Diazinon) 05/12/71 ■■■• 1500 150 ,01 (2,4,5-T) 07/14/71 ■"■ 1515 705 08/18/71 3 1330 150 09/08/71 = 1400 1500 .09 (DDT); .02 (2,4,5-T) USGS NO. 8-1140 BRAZOS RIVER AT RICHMOND. TEX. 11/26/68 12/23/68 01 /28/69 03/13/69 04 '18/69 06 06 69 06 13 69 07, 22 69 08/19/69 10/09/69 10/20/69 ,01 (DDD); .01 (DDE); .01 (DDT); .02 (2,4,5-T) ,01 (DDE); ,01 (DDT) ,01 (DDE); ,01 (DDT) .01 (DDD); .02 (DDE); .04 (DDT); .02 (2,4,5-T) 01 (DDD); ,05 (DDE); ,04 (DDT). .18 (2.4-D); ,04 (2,4,5-T) ,05 (2.4-D); .02 (2.4,5-T) ,06 (2,4-D); .02 (2,4,5-T) 1400 1115 79 Instan- Time taneous Date (24 Dis- Residues in mg/Liter Hour) charge (CFS) USGS NO. 8-1140 BRAZOS RIVER— Continued 10/27/69 12/04/69 02/19/70 03/19/70-- 04/29/70 = 05/18/70- 06/01/70 06/23/70 07/16/70 ■■ 08/18/70 3 08/19/70 = 11/03/70" 12/17/70 = 01/26/71 = 02/17/71 :'• 04/07/71 ■■■ 06/15/71 ■' 06/16/71 ■■•■ 07/21/71" 08/18/71 3 08/18/71 "■■ 09/24/71 ■■' 1110 1110 1230 1605 1640 0950 1200 1415 1425 1130 1330 1315 1430 1510 1500 1330 1315 1315 1600 1100 1445 1355 1310 1510 4610 21600 11100 7070 16400 3920 1370 1150 988 4370 754 910 595 510 625 940 575 1630 1590 1280 .01 (2.4,5-T) .01 (2,4,5-T) .03 (DDD); .04 (DDE); .08 (DDT); .04 (2.4-D); .02 (2,4,5-T) .01 (DDD); .01 (DDE); .01 (DDT); .01 (2,4,5-T) .06 (2,4-D); .01 (2,4,5-T) .03 (DDD); .04 (DDE); .06 (DDT); .01 (Lindane); .07 (2,4-D); .01 (2,4,5-T) .2 (PCB's) .01 (DDE); .02 (2.4,5-T); .3 (PCB's) .02 (Dicldrin); .5 (PCB's) I (PCB's) .01 (2,4,5-T) .06 (DDE); ,39 (DDT) .2 (PCB's) 01 (DDE); .01 (DDT); .01 (Dieldrin); .4 (PCB's) USGS NO. 8-1620 COLORADO RIVER AT WHARTON, TEX. 10/01/68 1400 579 12/19/68 1215 680 .02 (2,4,5-T) 01/21/69 1440 845 .03 (DDD) 03/05/69 125'^ 1430 .01 (Aldrin); .01 (DDT); .01 (Dieldrin) 04/23/69 0745 3870 .01 (DDE); .02 (DDT); .01 2,4,5-T) 06/04/69 0951) 2050 .04 (DDT); .03 (2,4,5-T) 06/ 13 '69 1045 1380 .01 (2,4,5-T) 07- 09/69 0950 1150 08/21/69 1745 900 .02 (DDT); .01 (Lindane) 10/09/69 1200 395 10/20/69 0930 2980 10/29/69 1610 2520 .01 iDDD) 12'0; 69 1520 2670 01/14/70 1630 3280 02/19/70 1045 2020 03/19/70 - 1400 9160 .01 (DDD); .01 (DDE); .03 .05 (2,4-D) (DDT); 04 29/70 - 1335 4150 .01 (DDT) 05/18/70- 1650 24200 .02 (DDD); .02 (DDE); .03 .40 (2,4-D); .06 (2,4.5-T) (DDT); 06/23/70 1250 2240 07/16/70-' 1114 3360 08/18/70 ■■ 1000 935 08/19/70 =1 1125 990 09/11/70 ■• 1100 1190 10/27/70 ■" 1400 3760 .01 (2,4,5-T) 12/17/70 ■' 1225 445 01/28/71 ■'■ 1235 358 02/17/71 •■ 1200 284 .04 (2,4,5-T) 04/07/71 ■■ 1215 860 06/03/7! - 0955 595 06/15/71 = 1205 885 06/16/71 " 1100 920 07/21/71 •■ 1235 691 08/18,71 = 1300 639 08/18/71 = 1330 639 09/21/71 •-• 1730 1770 iins in Western United States — Continued Instan- 1 Time taneous Date (24 Dis- RESrnUES IN /iG/I.ITER Hour) charge (CFS) USGS NO. 8-4692 RIO GRANDE BELOW ANZALDUAS dam, TEX. 10/15/68 0745 540 .01 (DDE) 11/20/68 1010 2240 .02 (Silvex) 12/26/68 1240 1320 01/16/69 0830 3090 02/17/69 1020 650 03/13/69 0930 381 04/14/69 1135 1400 05/15/69 0805 501 .01 (DDE) 06/19/69 0740 4310 07/16/69 0735 1910 .02 (DDD); .01 (DDE); .01 (DDT);. .01 (Lindane) 08/27/69 0850 509 09/18/69 0730 699 10/13/69 1210 800 11/18/69 1310 1000 12/17/69 0900 1240 01/19/70 1200 300 .02 (DDT) 02/24/70 - 1100 330 03/16/70 = 0900 1020 04/07/70 0830 1770 05/11/70 = 0745 2610 .01 (DDE); .01 (2,4,5-T) 06/18/70 0830 1590 07/16/70 = 1135 100 ()1 (DDD);.01 (DDE);.01 (DDT);.23 (Methly parathion; 1.0 (Parathion) 08/19/70" 0900 1260 10/13/70 ■• 0800 125 1 1/16/70 ■ 1045 400 12/18/70 ■■ II 15 600 01/15/71 ■' 1210 2200 02/26/71 ■' 1105 1040 03/17/71 ■■• 1025 1100 04/16/71 = 1135 200 05/20/71 ■•• 0945 2200 06/17/71 ■• 0800 3000 m/l9/ll ■< 0955 400 .01 (2.4.5-T) 08/12/71 ■■ 1020 10 10/15/71 ■■ 1155 41200 .02 (DDE) USGS NO. 8-3965 PECOS RIVER NEAR ARTESIA, N. MEX. 10/01/68 11/01/68 12/02/68 01/03/69'' 02/04/69 03/03/69 04/01/69 05/01/69 06/02/69 07/01/69 08/01/69 ' 09/02/69 10/01/69 1 1 '04/69 12/01/69 01/02/70 02/02/70 03/02/70 = 04/01/70 05/01/70 = 06/01 70 07/01/70 = 08/03/70 = 09/01/70 = 1340 3.8 0925 34 .02 (DDD); .01 (DDE); .46 (DDT); .01 (Lindane) 1225 45 ,15 (2,4-D) 1145 42 ,10 (2,4-D); .05 (2,4,5-T) 1225 40 1225 36 .02 (Chlordane) 1230 787 1345 33 1045 12 1320 646 1045 6.4 1250 230 .02 (DDT) 1345 101 1410 157 ,01 (Dieldrin); .02 (Lindane) 1140 78 1345 74 .01 (Lindane) 1305 64 1310 52 .01 (Lindane); .08 (Methyl parathion) 1240 9.6 1115 6.2 1345 693 1150 214 1430 703 1240 24 .01 (DDT) 80 Pesticides Monitoring Journal I TABLE 2. — Peslicide content of selected streams in Western United States — Continued Instan- Time taneous Date (24 Dis- Residues in ^g/Liter Hour) charge (CFS) USGS NO. 8-3965 PECOS RIVER— Continued 10/01/70 '■ 1400 91 11/02/70--' 1315 54 12/02/70' 1230 50 01/04/71 ■■ 1430 45 02/01/71 ' 1245 37 03/01/71 " 1245 38 .01 (Silvex) 04/01/71 " 1215 6.2 .01 (Silvex); .04 (2,4,5-T) 05/03/71 - 1145 57 06/01/71" 1330 39 07/01/71 " 1230 .96 08/02/71 ■-■ 1120 422 .01 (DDT) 09/01/71 ■■ 0900 53 .04 (2,4-D) USGS NO. 9-5255 COLORADO RIVER (YUMA MAIN CANAL) AT YUMA. ARIZ. (Beginning October 1970, samples collected at Imperial Dam. 15 miles northeast of Yuma) 10/01/68 0930 556 11/05/68 1030 476 12/03/68 1430 206 01/07/69 0930 3.0 .14 (2,4-D); .03 (2,4,5-T) 02/04/69 1000 365 03 04/69 0915 411 .24 (2,4-D); .04 (SUvex); .07 (2,4,5-T) 04 ns '69 1315 492 05 06 '69 0920 422 06, 0.1/69 ' 0940 639 07/01/69 0930 610 08/11/69 0825 547 09/02/69 1345 467 10/07/69 1030 625 11/04/69 1115 274 12/02/69 1100 75 01/06/70 1100 274 02/03/70 1115 373 03 03 70 - 0930 119 D4 07 70 IIOO 711 05/05/70 - 1030 637 06/02/70 1045 586 17 -07 '70 - 0930 469 as 04 70 ■- loon 600 19/01/70 ■' 1330 400 10/27/70 " 1100 6870 11/10/70" 1130 5360 12/01/70 = 1015 3710 ni (DDT) D 1/05/71 ■•• 0820 6480 32/02/71 - 0930 6160 ■)3/02/7l •■ 1445 8770 M/06/71 - 0915 11200 D5/04/7I " 1000 8830 16/01/71 ■■ 1030 9190 )7 06 '71 ■ 0835 10900 )8'03 '71 ■> 0826 10900 59/07/71 ■■ 0815 7800 USGS NO. 9-3150 GREEN RIVER AT GREEN RIVER, UTAH 10/14/68 1800 3620 11/18/68 1000 3850 .01 (DDT) 12/13/68 1245 4330 )l/15/69 1345 3880 82/11/69 1320 5720 )3/14/69 1240 5750 )4/ 10/69 1045 11100 Instan- TllWE taneous Date (24 Dis- Residues in ^o/Liter Hour) charge (CFS) USGS NO. 9-3150 GREEN RIVER— Continued 05/12/69 1645 19600 06/10/69 1320 9550 07/03/69 1100 9690 08/14/69 1230 4590 09/17/69 1340 4210 10/08/69 1105 3080 11/13/69 1155 3800 12/11/69 1650 3540 01/08/70 1350 2740 02/06/70 1520 2520 03/09/70-' 1330 3400 .1 (PCB's) 04/09/70 1205 2970 05/13/70 = 1330 10900 .01 (DDT) 06/16/70 1400 18400 07 09/70 - 1315 9290 08 06/70 - 1245 3260 .15 (2,4.5-T) 09/09/70 " 1115 3130 10/06/70 ■' 1215 2900 11/11/70 = 1230 2560 12/08/70 = 1115 2580 01/20/71 = 1325 2560 02/09/71 = ' 1110 2860 03/09/71 = 1000 2600 04/ 12/1 [ = 1230 5810 05/11/71 = 1300 11400 06/08/71 = 1300 14800 07/06/71 = 1200 9060 08/10/71 = < 1330 3380 09/08/71 = 1245 3610 USGS NO. 9-5180 GILA RIVER ABOVE DIVERSIONS AT GILLESPIE DAM, ARIZ. (Formerly published as USGS .No. 9-5195 Gila River below Gillespie Dam, Ariz.; for this location, discharge reported is daily mean discharge) 10/16/68 1000 22 .03 (DDD); .08 (DDE); .02 (DDT); .03 (Dieldrin); .01 (Lindane) 11 19/68 1200 21 .01 (DDD); .04 (DDE); .02 (DDT); .01 (Dieldrin); .01 (Lindane); .11 (Silvex) 12 16 68 1245 19 .01 (DDD); .10 (DDE); .05 (DDT); .03 (Dieldrin); .07 (Lindane) 01/15/69 1000 33 .02 (DDD); .04 (DDE); .01 (DDT); .01 (Dieldrin); .01 (Lindane); .06 (Silvex) 02/17/69 1025 26 .03 (DDE); .01 (DDT); .01 (Dieldrin); .01 (Lindane) 03/14/69 1315 29 .02 (DDE); .01 (Lindane) 04/17/69 1240 28 .02 (DDE); .01 (Dieldrin); .02 (Lindane) 05/20/69 1315 26 .01 (DDD); .02 (DDE) 06/18/69 1410 26 .01 (DDD); .06 (DDE); .02 (Dieldrin); .01 (Lindane) 07 16/69- 1300 12 08/20/69 1100 7.9 .02 (DDD); .05 (DDE); .03 (DDT) 09/17/69 1120 20 .02 (DDE); .03 (DDT); .03 (Endrin); .01 (Lindane) 10/13/69 0915 14 .01 (DDD); .01 (DDE); .01 (DDT); .01 (Dieldrin); .01 (Endrin); .02 (Lindane); .01 (2,4,5-T) 11/21/69 1300 26 .01 (DDD); .03 (DDE); .01 (DDT); .02 (Lindane); .05 (2,4-D) 12/18/69 1205 7.2 .04 (DDD); .02 (DDE); .02 (DDT); .02 (Lindane); .03 (2,4-D) 01/22/70 1030 31 .02 (DDD); .04 (DDE); .02 (DDT); .01 (Lindane) 02/17/70 1215 23 .02 (DDD); .04 (DDE); .01 (DDT); .01 (Endrin); .02 (Lindane); .02 (Endosulfan) Vol. 7, No. 1, June 1973 81 TABLE 2. — Pesticide content of selected streams in Western United States — Continued Instan- Time taneous Date (24 Dis- Residues in //o/Liter Hour) charge (CFS) Instan- Time taneous Date (24 Dis- Residues in /ig/Liter Hour) charge (CFS) USGS NO. 9-5180 GILA RIVER ABOVE DIVERSIONS AT GILLESPIE DAM, ARIZ— Continued 04/01/70=1 1200 1.3 .02 (DDD): .05 (DDE); .01 (DDT); .01 (Lindane) 05/04/70 -■ 1345 -)-) .02 (DDD); .03 (DDE); .01 (DDT) 06/03/70 1140 7.3 .01 (DDD); .04 (DDE); .01 (DDT) 07/02/70 = 1530 4.0 .01 (DDD); .02 (DDE); .01 (Dieldrin) 07/30/70 = 1500 5.4 .01 (DDD); .04 (DDE) 09/01/70 = 1200 17 .02 (DDE); .04 (Methyl parathion); .04 (Parathion) 10/01/70' 1210 36 .01 (DDE); .01 (Lindane); .02 (Methyl parathion); .04 (Parathion) 11/02/70 3 1230 38 .02 (DDE); .10 (Methyl parathion); .10 (Diazinon) 12/02/70 = 1500 65 .01 (DDE); .06 (Lindane) 01/08/71' 1600 49 .05 (DDE); .02 (DDT); .01 (Dieldrin); .05 (Lindane) 02/01/71 5 1030 26 .01 (DDE); .01 (Dieldrin); .01 (Lindane) 03/02/71 ' 1030 39 .01 (DDE); .01 (Dieldrin); .01 (Lindane) 04/06/71 ' 1245 35 .02 (DDD); .08 (DDE); ,01 (Lindane) 05/07/71 ' 1030 28 .02 (DDE); .01 (Diazinon) 06/01/71 i 1200 36 .02 (DDE); .04 (Diazinon) 07/01/71 ' 1130 10 .02 (DDE) 08/18/71 ' 1030 302 .01 (Silvcx) 09/01/71 ' 1640 27 .03 (DDE); .05 (DDT) USGS NO. 10-3350 HUMBOLDT RIVER NEAR RYE PATCH. NEV. 10/01/68 0930 48 .14 (Silvex) 11/01/68 0845 0 .05 (Silvex) 12/02/68 0900 .6 .01 (Silvex) 12/31/68 1000 .6 ,18 (2.4-D); .07 {2,4.5-T) 02/03/69 0915 .8 03/03/69 0900 .9 .02 (Silvex) 04/01/69 1100 2.0 .02 (Silvex) 05/01/69 0915 602 .01 (DDT); .07 (Silvex) 06/02/69 0845 642 .10 (Silvex) 06/30/69 1030 320 .11 (Silvex) 08/01/69 0900 288 .08 (Silvex) 09/02/69 I20O 180 .07 (Silvex) 10/01/69 1200 114 .06 (Silvcx) 11/03/69 1030 137 .05 (Silvcx) 12/01/69 0845 13 .03 (SUvex) 01/02/70 1300 16 .05 (Silvcx) 02/02/70 0930 16 .05 (Silvcx) 03/03/70 = 0930 15 .05 (Silvex) 04/01/70 1030 142 .01 (Lindane); .05 (Silvex) 05/01/70 = 1300 495 .06 (Silvcx) 06/01/70 1100 396 .04 (Silvex) 07/01/70 = 1000 310 .03 (Silvex) 08/31/70 ■•' 1315 195 .01 (Silvcx) 10/01/70 ■•• 1130 105 .02 (Silvex) 11/03/70' 1015 49 ,02 (Silvex) 12/01/70' 1100 16 ,02 (Silvcx) 12/31/70' 1030 13 .01 (Silvcx) 02/01/71 ' 1200 68 .01 (Silvcx) 03/01/71' 1200 333 .02 (Silvex) 04/01/71 ' 1100 523 .02 (Silvex) 05/03/71 ' 1130 867 .01 (Silvcx) 06/01/71 ' 1100 1580 07/02/71 ' 1200 1570 09/01/71' 1100 238 USGS NO. 11-4255 SACRAMENTO RIVER AT VERONA, CALIF. 11/15/68 1100 12000 12/12/68 1100 23200 .22 (2.4-D); .08 (2.4.5-T) 01/17/69 1145 59300 03,05/69 1630 56700 04/17/69 1110 37200 06/05/69 0930 22600 07/03/69 1000 11700 08/19/69 0945 16600 .01 (DDT); .02 (2,4-D); .03 (2,4,5-T) 10/27/69 1540 12700 .04 (2,4-D); .01 (Silvex); .02 (2,4,5-T) 12/04/69 1400 12800 12/30/69 1045 60300 .01 (2.4.5-T) 03,/ 03/ 70 = 1430 51300 .07 (2,4-D) 04/08/70 0915 14200 05/21/70 = 1035 11300 .02 (2,4-D); .01 (2,4,5-T); .10 (Methyl parathion); .16 (Parathion) 07/01/70 = 1025 10700 .01 (Silvex) 08/11/70' 1135 11900 .01 (Silvex) 09/24/70 ' 0900 13900 10/29/70 ' 0950 14000 11/25/70' 0930 21700 12/09/70' 0930 61600 01/20/71' 1300 62800 02/09/71 " 1445 30900 02/24/71 ' 0930 18100 04/07/71 ' 1100 38300 05/10/71 ' 1005 27400 ,13 (Methyl parathion); ,04 (Parathion) 06/16/71' 0915 22700 07/21/71' 0900 16500 08/26/71 ' 0910 22400 09/21/71 ' 0930 21600 USGS NO. 11-4070 FEATHE R RIVER NEAR OROVILLE, CALIF. 10/08/68 1330 393 .02 (DDT) 11/01/68 1645 393 12/— /68 1430 382 .99 (2,4-D); .18 (2,4,5-T) 01/03/69 0800 420 .06 (2,4-D); .07 (Silvex); .03 (2,4,5-T) 02/04/69 0800 411 03/04/69 0735 4930 03/28/69 1700 1730 05/01/69 0700 451 .06 (2,4,5-T) 06/05/69 1245 400 .01 (2,4,5-T) 07/02/69 1200 420 07/30/69 1 1000 410 09/04/69 0800 382 09/30/69 1745 411 10/30/69 1015 461 11/26/69 0928 426 12/31/69 1022 403 01/29/70 1040 35200 02/26/70 = 0915 419 03/27/70 0730 417 04/29/70 = 1500 420 05/27/70 = 1230 410 06/24/70 = — 415 08/03/70 = 1500 392 08/31/70' 1430 421 09/28/70 ' 1730 410 11/03/70' I30O 409 .02 (2,4.5-T) 12/01/70' 0815 409 12/30/70' 1605 409 01/29/71 = 1130 405 02/26/71 ' 1025 406 82 Pesticides Monitoring Journai TABLE 2. — Pesticide content of selected streams in Western United States — Continued Instan- TlMt taneous DaTI; (24 Hour) Dis- CHARCU (CFS) Residues in /ig/Liter USGS NO. 11-4070 FEATHER RIVER NEAR OROVILLE, CALIF.— Continued )3/26/71 ■■ 0830 433 .03 (Silvex) )4/29/71 ■ 1300 409 )5/24/7l ■■ 1500 411 )6/29/7I ■■ 1730 413 )7/29/71 ■■ 1300 404 )8/26/7I ■' 1400 411 )9/21/71" 1300 414 uses NO. IZ-.MO.'i YAKIMA RIVER AT KIONA, WASH. t [1/25/68 1530 4070 112/16/68 1040 3480 ')l/20/69 1545 3820 12/25/69 1145 3230 13/26/69 0845 6150 14/09/69 0930 6960 .20 (2.4-D) 15/19/69 1530 8200 .01 (ODD); .01 (DDE); .04 (DDT); .24 (2.4-Dl •16/27/69 1015 1720 .01 (DDE); .04 (DDT); .01 iDleldrin); .21 (2.4-D) 07/30/69 0930 1300 .01 (DDD); .03 (DDT); .02 (Dieldrin); .18 (2,4-D) ■18/21/69 1305 1550 01 (DDD); ,01 (DDE); .02 (DDT): 01 (Dieldrin); .09 (2,4-D) ■19/09/69 1500 1740 .09 (2,4-D) 10/17/69 1510 3090 ,01 (DDT); .04 (2,4-D) 11/25/69 1430 1940 12/30/69 1330 2120 ,05 (2,4-D) 01/27/70" 0955 5350 .04 (2,4-D) D2/16/70 - 1545 4360 .01 (Dieldrin); .04 (2.4-D) D3/19/70 = 1210 4390 M/28/70- 1255 1790 .01 (DDT); .05 (2,4-D) 05/25/70 - 1630 4440 .01 (DDD); .01 (DDE); .02 (DDT); .42 (2.4-D); .01 (2.4, 5-T) 16/22/70 1055 2640 .02 (DDD); .01 (DDE); .02 (DDT); .01 (Dieldrin); .15 (2,4-D); .01 (2,4. 5-T) 17/20/70 : 1155 1300 .01 (Dieldrin); .16 (2.4-D); .01 (2,4, 5-T) 18/24/70- 1420 1600 .01 (DDD); .01 (DDE); .18 (2,4-D) 19/30/70 1415 1820 10/15/70 •■ 1140 2330 .04 (2,4-D) 11/24/70 = 1150 1920 12/29/70 = 1015 1970 ^\ilin\ ' 1025 7600 .06 (2,4-D); ,01 (2,4,5-T) 02/03/71 •■■ 1415 11200 03/01/71 = 1435 4490 04/05/71 = 1200 3590 05/07/71 ■■ 1640 10200 01 (DDT) 06/21/71 ■-• 1150 5940 ,01 (DDT); .07 (2,4-D) 07/16/71 ■■ 1115 2200 .01 (DDT); .27 (2,4-D) 08/06/71 ••■■ 1635 1240 -02 (DDE ) ; .01 ( DDT 1 ; 01 ( nicldriii ) . .18 (2,4-n) 09/23/71 = ' 1355 2380 USGS NO, 13-1545 SNAKE RIVER AT KING HILL, IDAHO 10/01/68 1315 10700 ,02 (DDT) 11/04/68 1115 10600 12/14/68 1100 1 2940 11/20/69 1100 I6S00 ,04 (2,4,5-T) 13/07/69 1300 16000 Instan- Time taneous Date (24 Dis- Residues in ^g/Liter Hour) charge (CFS) USGS NO, 13-1545 SNAKE RIVER AT KING HILL, IDAHO— Continued 04/18/69 1545 10700 05/23/69 1450 9860 .09 (2,4-D) 06/23/69 1 0830 5330 07/14/69 1115 6190 .06 (2,4-D) 08/11/69 1030 4950 .02 (DDT); .03 (2,4-D) 09/08/69 1235 8210 .03 (DDT); ,05 (2,4-D) 10/06/69 1515 12200 ,05 (DDT); .04 (2,4-D) 1 1 /09/69 1430 12000 12/15/69 1655 11700 .01 (DDD); .03 (DDT): .01 (Dieldrin); ,02 (2,4-D) 01/13/70 1635 1300O .12 (DDT) 02/09/70 1 155 10200 .01 (DDT) 03/15/70 - 1345 7440 .03 (DDT) 04/20/70 1200 14900 .01 (DDT); .16 (Lindane) 04/30/70 -■ 0930 13700 05/11/70-' 1450 17600 .01 (DDT) 06/08/70 - 1340 10300 .04 (2,4-D) 07/11/70- 1550 7520 .01 (DDT); ,06 (2,4-D) 08/09/70 - 1515 9870 .04 (2,4-D) 09/18/70 = 1530 11100 .01 (DDT) 10/05/70 = 1045 11200 .06 (2,4-D) 1 1/20/70 = 1725 13400 .01 (DDT) 01/08/71 = 1030 14100 .01 (2,4,5-T) 01/28/71 = 1300 17100 02/27/71 = 1600 14600 03/27/71 = 1315 16600 05/05/71 ■■■ 1 345 25200 05/25/71 = 1258 18500 .02 (2,4.5-T) 06/21/71 = 1305 14400 08/02/71 ■■■ 1800 7660 .02 (2,4-D) 08/30/71 =■ 1435 7630 USGS NO. 14-1057 COLUMBIA RIVER AT THE DALLES, OREG. 11/05/68 1030 144000 12/09/68 1000 122000 .26 (2,4-D); ,07 (2,4,5-T) 01/22/69 1430 230000 03 18/69 1430 207000 05/07/69 1230 316000 06 26,69 0830 292000 08/06/69 1200 127000 09/16/69 1530 87000 10/21/69 1545 112000 01 (2,4-D) 12/02/69 1435 163000 01/14/70 1130 127000 03/03/70- 1610 19700O 04/13/70 1415 168000 06/26/70 -■ 1200 299000 .25 (2,4-D) OS/20/70 = 1400 155000 11/05/70 = 1200 125000 12/17/70 = 1300 106000 01/21/7! = 1400 193000 03,09/71 ■ 0950 211000 .01 (DDT) 04'I4/7I ■ 1010 227000 06/09/71 = 1545 5 1 2000 07/15/71 = 0940 300000 09/01/71 = 1010 136000 1 Daily mean discharge. = Sample also analysed for methyl paralliion, parathion, and dia/inon, ■ Sample aKo analyzed for methyl parathion, parathion, dia?inon, and malathion, ' Sample not obtained for 2,4-D, silvex, or 2,4,5-T analysis. = Sample not obtained for organochlorine insecticide analysis. Vol. 7, No. 1, Junl 197.^ 83 TABLE 3. — Number of occurrences of pesticides, October 1968 to September 197! Number of Occurrences Stream and Location z < Q D D m a a a z < a: 3 U a z i z w H a. X Xu u z < Q z UJ Z 2 g s U CL. i z < i o Q z H Q ri X > w5 < Missouri River at Nebraska City, Nebr. 0 2 0 6 6 n n 0 2 0 0 0 10 1 3 30 Yellowstone River near Billings, Mont. 0 0 0 0 0 0 0 0 0 0 0 0 3 0 1 4 James River at Huron, S. Dak. 0 0 0 n n II n 0 3 0 0 0 20 0 3 26 Platte River at Brady, Nebr. n 0 0 1 n n 0 0 0 0 0 0 3 1 1 6 Arkansas River below John Martin Reservoir, Colo. 0 3 2 4 _s 0 0 0 3 0 0 0 3 1 3 24 Arkansas River at Van Buren, Ark. 0 3 1 9 1 0 0 0 1 0 0 11 5 0 24 44 Canadian River near Whitefield, Okla. 0 1 n 3 n 0 0 0 2 0 0 0 2 1 27 36 Brazos River at Richmond, Tex. 0 6 II 10 2 0 0 0 1 0 0 0 6 0 13 49 Colorado River at Wharton, Tex. 1 4 3 7 1 0 0 0 1 0 0 0 2 0 7 26 Rio Grande below Anzalduas Dam, Tex. 0 2 6 3 (1 0 (1 0 1 0 0 0 0 1 2 15 Pecos River near Artesia, N. Mex. 0 1 1 4 1 0 n 0 4 1 0 0 3 2 2 19 Colorado River (Yuma Main Canal) at Yuma, Ariz. (1 (1 n 1 n n n 0 II 0 0 0 2 1 2 6 Green River at Green River, Utah 0 0 n 2 n 1) 0 11 0 II 0 0 0 0 1 3 Gila River at Gillespie Dam, Ariz. 0 IK 33 17 12 3 0 0 21 0 0 1 2 3 1 111 Humboldt River near R.vc Patch, Nev. 0 0 0 1 0 n n 0 0 n 0 n 1 29 1 32 Sacramento River at Verona, Calif. n (1 n 1 0 n 0 0 n n 0 0 .s 3 ■; 14 Yakima River at Kiona, Wash. 0 6 7 12 7 n n 1) n II 0 0 20 0 4 56 Snake River at King Hill, Idaho n 1 n 13 1 0 0 0 1 n 0 n II 0 3 30 Columbia River at The Dalles, Oreg. n n 0 1 0 0 n n 0 0 II II 3 0 1 5 Feather River at Oroville, Calif. 0 0 0 1 0 0 0 0 0 n 0 0 2 2 5 10 TOTAL,S 1 47 64 96 36 3 0 0 40 1 0 1 103 45 109 546 NOTE: Only the occurrences of pesticides looked for dt ring the e ntire study perio d, Oc ober 1968-September 1971, are included in this table. 84 P ESTK IDES Monitoring Journal APPENDIX Chemical Names of Compounds Discussed in This Issue''' LDRIN RSENIC HC ADMIUM HLORDANE 4-D DE DT (including its isomers and dehydrochlorination products) 'lAZINON lELDRIN NDOSULFAN (THIODAN®) ;ndrin CB tEPTACHLOR lEPTACHLOR EPOXIDE EAD INDANE lALATHION lERCURY lETHYL PARATHION IIREX ARATHION OLYCHLORINATED BIPHENYLS (PCB's) ILVEX ,4,5-T DE (DDD) (including its isomers and dehydrochlorina- tion products) OXAPHENE Not less than 95% of l,2,3,4,10,10-hexachloro-I,4,4a,5,8,8a-hexahydro-l,4-cn(/o-«'.TO-5,8-dimethaiionaphthalene As 1 .2.3,4.5,6-hexachlorocyclohexanc, mixed isonicr"^ Cd l,2,4,5,6,7,8,8-octachloro-3a.4,7,7a-tetrahydro-4,7-methanoindane 2,4-dichlorophenoxyacetic acid l,l-dichIoro-2,2-bis(p-chlorophenyl) ethylene l.I,l-trichIoro-2,2-bis(p-chlorophenyl)ethane; technical DDT consists of a mixture of the p,p'-isomcr and the o,p'-isomer (in a ratio of about 3 or 4 to I ) 0,0-diethyl 0-(2-isopropyl-4-meihyl-6-pyrimidyl ) phosphorothioate Not less than 85% of 1,2,3,4, in. in-hexachloro-6.7-epoxy-1.4,4a.5,6,7.8a-octahydro-l,4-PHrfo-cxo-5,8-dimethano= naphthalene 6,7,8,9,10, 10-hexachloro-l,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin 3-oxidc 1,2,3,4, 10, 10-hexachloro-6,7-c poxy- 1, 4,4a, 5,6, 7,8,8a-octaliydro-l,4-c;ido-f;i(/o-5,8-dimethanonaphthalene hcxachlorobenzenc l,4,5,6,7,8,8-heptachloro-3a,4,7,7a-tetrahydro-4.7-iiiethanoindenc l,4,5,6,7,8,8-hcptachloro-2,3-epoxy-3a,4,7,7a-tetrahydro-4.7-methanoindan Pb 1,2,3,4,5,6-hexachlorocyclohexane, 99% or more gamma isomer diethyl mercaptosuccinate, .V-cster with 0,(7-dimcthyl phosphorodithioale Hg 0,0-dimethyl O-p-nitrophenyl phosphorothioate dodecachlorooctahydro-l,3,4-metheno-l//-cyclobuta[cd|pentalene 0. 0-diethyl (?-p-nitrophenyl phosphorothioate Mixtures of chlorinated biphcnyl compounds having various percentages of chlorination 2-(2,4,5-trichlorophcnoxy )propionic acid 2,4,5-trichlorophenoxyacetic acid l,l-dichIoro-2,2-bis(p-chlorophenyliethane; technical TDE contains some o,p'-isomer also chlorinated camphenc containing 67-69'?r chlorine ''oi,. 7, No. I, .luNi- 197.^ 85 Information for Contributors The Pesticides Monitoring Journal welcomes from all sources qualified data and interpretive information which contribute to the understanding and evaluation of pesticides and their residues in relation to man and his environment. The publication is distributed principally to scientists and technicians associated with pesticide monitoring, research, and other programs concerned with the fate of pesticides following their application. Additional circulation is maintained for persons with related in- terests, notably those in the agricultural, chemical manu- facturing, and food processing industries: medical and public health workers; and conservationists. Authors are responsible for the accuracy and validity of their data and interpretations, including tables, charts, and refer- ences. Accuracy, reliability, and limitations of the sam- pling and analytical methods employed must be clearly demonstrated through the use of appropriate procedures, such as recovery experiments at appropriate levels. confirmatory tests, internal standards, and inter-labora- tory checks. The procedure employed should be ref- erenced or outlined in brief form, and crucial points or modifications should be noted. Check or control samples should he employed where possible, and the sensitivity of the method should be given, particularly when very low levels of pesticides are being reported. Specific note should be made regarding correction of data for percent recoveries. Preparation of manuscripts should be in con- formance to the CBE Sty IE M.anuai . 3d ed. Coun- cil of Biological Editors. Committee on Form and Style. American Institute of Biological Sciences. Washington, D. C. and/or the Style Manual of The United States Government Printing Office. An abstract (not to exceed 200 words) should accompany each manuscript submitted. All material should be submitted in duplicate (original and one carbon) and sent by first-class mail in flat form — not folded or rolled. Manuscripts should be typed on SVi x 11 inch paper with generous margins on all sides, and each page should end with a completed para- graph. All copy, including tables and references, should be double spaced, and all pages should be num- bered. The first page of the manuscript must contain authors" full names listed under the title, with affiliations, and addresses footnoted below. Charts, illustrations, and tables, properly titled. should be appended at the end of the article with a notation in text to show where they should be inserted. Charts should be drawn so the numbers and texts will be legible when considerably reduced for publication. All drawings should be done in blacki ink on plain white paper. Photographs should be made on glossy paper. Details should be clear, but size is not important. The "number system" should be used for litera- ture citations in the text. List references in thei order in which they are cited in the text, giving! name of author/ s/, year, full title of article, exact name of periodical, volume, and inclusive pages. ^ The Journal also welcomes "brief" papers reporting! monitoring data of a preliminary nature or studies of or limited scope. A section entitled Briefs will be included, as necessary, to provide space for papers of this type to present timely and informative data. These papers i must be limited in length to two journal pages (850' words) and should conform to the format for regular! papers accepted by the Journal. Pesticides ordinarily should be identified by commoni or generic names approved by national scientific so-> cieties. The first reference to a particular pesticidei should be followed by the chemical or scientific name in parentheses — assigned in accordance with Chemical Abstracts nomenclature. Structural chemical formulas^ should be used when appropriate. Published data and ' information require prior approval by the Editorial Advisory Board; however, endorsement of published in-' formation by any specific Federal agency is not intended I or to be implied. Authors of accepted manuscripts will receive edited typescripts for approval before type is set. After publication, senior authors will be provided with 100 reprints. Manuscripts are received and reviewed with the under- standing that they previously have not been accepted for technical publication elsewhere. If a paper has been given or is intended for presentation at a meeting, or if a significant portion of its contents has been published or submitted for publication elsewhere, notation of such should be provided. Correspondence on editorial matters or circulation mat- ters relating to official subscriptions should be addressed to: A/;v. Sylvia P. O'Rear. Editorial Manager. Phsti- cini s MoNiTORiNf. louRNAi . I^ivision of Technical Serv- ices. Office of Pesticide Programs. V. S. Environmental Protection Agency. 4770 Buford Highway. Bldg. 29. Chamblee. Ga. 30341. 86 Pesticides Monitoring Journai The Pesticides Monitoring Journal is published quarterly under the auspices of the FEDERAL WORKING GROUP ON PEST MANAGEMENT (responsible to the Council on Environ- mental Quality) and its MONITORING PANEL as a source of information on pesticide levels relative to man and his environment. The WORKING GROUP is comprised of representatives of the U. S. Departments of Agricul- ture; Commerce; Defense; the Interior; Health, Education, and Welfare; State; Transportation; and Labor; and the Environmental Protection Agency. The pesticide MONITORING PANEL consists of representatives of the Agricultural Research Service, Consumer and Marketing Service, Extension Service, Forest Service, Department of Defense, Fish and Wildlife Service, Geological Survey, Food and Drug Administration, En- vironmental Protection Agency, National Marine Fisheries Service, National Science Founda- tion, and Tennessee Valley Authority. Publication of the Pesticides Monitoring Journal is carried out by the Technical Services Division of the Environmental Protection Agency. Pesticide monitoring activities of the Federal Government, particularly in those agencies repre- sented on the pesticide MONITORING PANEL which participate in operation of the national pesticides monitoring network, are expected to be the principal sources of data and interpretive articles. However, pertinent data //; summarized form, together with interpretive discussions, are invited from both Federal and non-Federal sources, including those associated with State and community monitoring programs, universities, hospitals, and nongovernmental research institu- tions, both domestic and foreign. Results of studies in which monitoring data play a major or minor role or serve as support for research investigation also are welcome; however, the Journal is not intended as a primary medium for the publication of basic research. Manuscripts received for publication are reviewed by an Editorial Advisory Board established by the MONITORING PANEL. Authors are given the benefit of review comments prior to publication. Editorial Advisory Board members are : John R. Wessel, Food and Drug Administration, Chairman Paul F. Sand, Agricultural Research Service, Vice Chairman Anne R. Yobs, Environmental Protection Agency William F. Durham, Environmental Protection Agency Thomas W. Duke, Environmental Protection Agency William H. Stickel, Fish and Wildlife Service Milton S Schechter, Agricultural Research Service Herman R. Feltz, Geological Survey Mention of trade names or commercial sources in the Pesticides Monitoring Journal is for identification only and does not represent endorsement by any Federal agency. Address correspondence to: Mr. Paul Fuschini Editorial Manager PESTICIDES MONITORING JOURNAL U. S. Environmental Protection Agency Room B49 East, Waterside Mall 401 M Street, S.W. Washington, D. C 20460 CONTENTS Volume 7 September 1973 Number 2 Page RESIDUES IN FOOD AND FEED Residues of mirex and certain other chlorinated hydrocarbon insecticides in heef fat— 1971 g^ J. H. Ford, J. C. Hawthorne, and G. P. Markin Residues of PCB's and PCT's in Canadian and Imported European Cheeses, Canada — 1972 95 David C. Villeneuve, Lincoln M. Reynolds. and William E. J. Phillips RESIDUES IN FISH, WILDLIFE. AND ESTUARIES Organochlorinc insecticide residues in wild moose, Idaho — 1972 97 W. W. Benson, Michael Watson, and Joe Wyllie Organochlorinc residues in woodcock wings, II States— 1970-71 100 MAR. McLane, Lucille F. Stickel, Eldon R. Clark, and Donald L. Hughes Mirex incorporation in the environment: residues in nonlarget organisms — 1972 . IO4 Syed M. Naqvi and Armando A. de la Cruz Accutnulation of mirex residues in selected organisms after an aerial treatment, Mississippi — 1971-72 H; James L. Wolfe and B. R. Normenl APPENDIX Chemical names of compounds discussed in this issue- j jy RESIDUES IN FOOD AND FEED Residues of Mirex and Certain Other Chlorinated Hydrocarbon Insecticides in Beef Fat — 7977 ' J. H. Ford, J. C. Hawthorne, and G. P. Markin ABSTRACT Samples of fat from beef cattle were obtained in areas of Mississippi and Georgia where the insecticide mirex had been used to control the imported fire ant. Mirex residues were detected in 67 of the 77 fat samnles nna'v'-'i with levels ranging from 0.001 'lowest level of detection) to 0.125 ppm, with an average residue level of 0.025 ppin. Sixty-nine samples of fat jrom beef cattle from nonmirex treated areas were also analyzed: none contained mirex. All fat samples contained residues of DDT. Introduction Mirex in a bait form is at present the recommended method of controlling the imported fire ant, Solenopsis invicia (Buren) (2), which is a serious agricultural pest in nine southeastern States (/). Since mirex is a very stable chlorinated hydrocarbon insecticide (4) capable of being stored in fat, cattle grazing on treated pastures would possibly accumulate residues of this insecticide This study was undertaken by the U. S. Department of Agriculture as part of a series of studies to determme the environmental distribution of mirex following ap- plication. Sample Collection The samples of beef fat for this study were taken from cattle from two areas, heavily infested with fire ants. lU S Department of Agriculture, Animal and Plant Health Inspectiori Service Plant Protection and Quarantme Programs, Enviromenlal Quality Laboratory, P. O. Box 989. Gulfport. Miss. 39501 Vol. 7, No. 2, September 1973 which were known from USDA records to have received blanket applications of mirex at least twice in the past 3 years. The areas included the northeastern Mississippi region of Oktibbeha, Prentiss. Lee, Lowndes, and Ita- wamba Counties, and central Georgia between Macon and Tifton. USDA inspectors collected information on the specific animals from which samples were collected and the treatment history of the pertinent areas. Since the normal method of residue analysis for meats is to utilize the fat. State meat inspectors were requested to collect 1,000-g samples of subcutaneous fat from five different locations on the freshly-dressed carcass. These five samples were combined into a single composite sample for the animal (1,000 g). wrapped in aluminum foil, and frozen; Vi kg of this composite sample was sent to the Environmental Monitoring Laboratory in Gulfport, Miss., for processing. Since this program was conducted in cooperation with the respective State De- partments of Agriculture, a Vi kg of each sample was also sent to the respective State laboratory for replicate analysis. Samples were also obtained in a similar manner from cattle in check areas outside the region where mirex had been used. The data on individual animals, however, were not as complete. Verification that the animal had come from outside the treated area was obtained from the State meat inspector. 87 Analytical Procedures METHOD OF EXTRACTION Twenty grams of thoroughly mixed rendered fat was placed in a 1-qt canning jar containing 100 ml of distilled-in-glass isopropanol. This mixture was then blended for 2-3 minutes on a Lourdes blendor assembly; 300 ml of distilled-in-glass hexane was then added to the blended mixture with small portions being used to rinse the blendor blades. The jar was sealed with a teflon-lined cap and rotated on a concentric rotator for 2 hours. The extract was filtered through glass wool which was prewashed with distilled-in-glass acetone followed by distilled-in-glass hexane. A 300-ml aliquot of the filtered extract (representing 15 g of sample) was placed in a 1 -liter separatory funnel and shaken for 1 or 2 minutes with 250 ml of distilled water. The layers were allowed to separate, and the lower layer containing water and isopropanol was discarded. A total of three successive washings with distilled water was utilized, discarding the lower water layer each time. The remaining hexane layer was then filtered through a filter tube (42 mm O.D. x 160 mm) containing a glass wool plug and anhydrous Na.jS04 and the dried hexane placed in a 500-ml 24/40 S-jointed Erlenmeyer flask. The filter tube was washed with several portions of distilled-in-glass hexane and these washings combined with the hexane extract. A three-ball Snyder column was then attached, and the sample concentrated to 25 ml on an explosion-proof hot plate. The concentrate was quantitatively transferred to a 50-ml graduate cylinder and the volume adjusted to 45 ml. HjSO. CLEANUP A 15-ml aliquot (representing 5 g of sample) was placed in a 125-ml separatory funnel and 35 ml of distilled-in-glass hexane added; 10 ml of concentrated H0SO4 was added to the sample, and the mixture was first swirled gently and then shaken and the pressure released. The layers were allowed to separate, and the lower acid layer was discarded. This acid wash was repeated, the acid layer again discarded, and the sample then washed three successive times with distilled water, discarding the lower water layer each time. The hexane sample was next filtered again through a filter tube con- taining anhydrous NaoS04 and prewashed glass wool into a 250-ml 24/40 S-jointed Erlenmeyer flask. The filter tube was washed with several small portions of distilled-in-glass hexane and the washings combined with the sample. A Snyder column was again employed, and the sample concentrated to about 10 ml on the hot plate. PREPARATION OF THE FLORISIL COLUMN The chromatographic column employed consisted of a 125-ml reservoir attached to an 1 1- x 150-mm glass tube. a removable teflon stojjcock, and a removable glass tip. A small piece of hexane-washed glass wool was placed in the bottom of the column and 1 inch of anhydrous NanS04 added; 18 g of 60/120 mesh PR grade un- activated Florisil was placed in the column with gentle tapping to insure even packing, and another 1-inch layer of NaoS04 was placed atop the Florisil. The column was then prewashed with 100 ml of distilled-in-glass methy- lene chloride and allowed to drain to the top of the upper layer of Na2S04. The washing was then repeated with 100 ml of distilled-in-glass hexane. The column was never allowed to go dry. The sample extract was then quantitatively transferred to the Florisil column. When the extract drained to the upper layer of Na2S04, 100 ml of a 5% by volume mixture of methylene chloride in hexane was added to the column and the sample collected until the eluant level reached the upper NanS04 level. This elution was labeled fraction one. A second fraction was collected using 100 ml of distilled- in-glass methylene chloride as the eluant. The second fraction was collected until the column ran dry. Mirex, heptachlor, p.p'-DDJ and its metabolites, and sometimes heptachlor epoxide appeared in the first fraction; the second fraction was collected because it also sometimes contains heptachlor epoxide. To the collection flasks were added 1 ml of a 0.01% Nujol solution in hexane and three or four glass beads. The Snyder column and hot plate were again employed, and the sample concentrated to about 5 ml. To the second fraction, 50 ml of hexane was added and again con- centrated to about 5 ml in order to remove all traces of methylene chloride. Five milliliters of distilled-in-glass hexane was poured through the top of the Snyder column and collected in the flask. This was done to rinse any volatilized pesticide from the column. The sample was then quantitatively transferred to a 15-ml graduated centrifuge tube and placed into a water bath maintained at 40° C. A stream of air was directed into the centrifuge tube until the volume was reduced to 2.5 ml. GAS CHROMATOGRAPHIC ANALYSIS Ten microliters of this sample (representing 20 mg of the original fat sample) were normally injected on the instrument. Two different column types, 6 feet in length and 14 inch O.D., were utilized as a confirmatory pro- cedure: a mixed column of 1.5% OV-17 and 1.95% QF-1 on 100/120 mesh Gas Chrom Q and a 3% DC-200 column on 100/120 mesh Gas Chrom Q. The mixed column was used in a MicroTek Model MT220; the oven temperature was 200°C, the injection port temperature 250°C, and the detector temperature 210°C. The flow rate was 80 ml/min of a nitrogen carrier gas. The DC-200 column was used in a Hewlett- Packard Model 402; the oven temperature was 175°C, 88 Pesticides Monitoring Journal the injection port temperature 245°C, and the detector temperature 205°C. The flow rate was 100 ml/min of 5% methane-95% argon carrier gas. Average recovery values of 90% for the fat sample were determined by fortification with composite pesticide standards. All data were corrected for percent recovery. The presence of polychlorinated biphenyls (PCB's) (Aroclor 1260®, in particular) in some of the samples interfered with the mirex analysis on both GC columns. In these samples the PCB's were separated using a modification (6) of the Armour-Burke method (7). Results and Discussion Mirex and certain other chlorinated pesticide residues detected in beef fat from the treated areas are reported in Table 1. Also presented in this table are residues of other tissues (fatty tissue, kidney, liver, and lean por- tion) from a few specimens. These analyses from our laboratory at Gulfport generally agreed within 10% with those from the State laboratories of Mississippi and Georgia. Residues of mirex were found in 88% of the samples from this area with levels ranging from 0.001 ppm (our lowest level of detection) to 0.125 ppm, with an average value of 0.026 ppm. Only one sample. 0.125 ppm, was in excess of the established tolerance level of 0.1 ppm for mirex in the fat of the beef cattle (4), Analysis of the other tissues showed no residues in the lean portions and very small residues in the fatty tissues from the same animals. Because mirex has been used previously as a fire ant re- tardant under the name Dechloran® (5). it was decided to examine samples collected from untreated areas, both in the Southeast and from other areas. These results are re{>orted in Table 2. The absence of mirex in samples from untreated areas, while not giving absolute proof that the residues found in samples from the treated areas were from the insecticide application, does strongly indicate that this is the case. It does show that prior uses of this compound have not made it ubiquitous in the Nation's environment. In general, we have concluded that residues can be expected in beef fat of animals in mirex-treated areas following the use of mirex, but that application in the prescribed manner will keep these residue levels below the tolerance level. LITERATURE CITED (1) Markin, G. P., J. H. Ford, J. C. Hawthorne, J. H. Spence, J. R. Davis, and C. D. Loflis. 1972. The insecticide mirex and techniques for its monitoring. APHIS 81-3. 19 pp. (2j U. S. Department of Agriculture. 1968. Suggested guide for the use of insecticides to control insects affecting crop, livestock, household stored products, forests, and forest products — 1968. Agricultural Handbook No. 331. (3) U. S. Department of Agriculture. 1969. Summary of registered chemical uses, mirex. p. III-D-45. (4) Gibson, J. R., G. W. Ivie, and H. W. Dorough. 1972. Fate of mirex and its major photodecomposition product in rats. J. Agric. Food Cheni. 2016): 1246-1248. (5) Hooker Industrial Chemicals. 1967. Fire ant retardant chemicals. Brochure Hooker Industrial Chemicals, De- chlorane Series: Dechlorane 510 and 4070, Data Sheet No. 341-B. (6) Gaul, J., and P. Cruz-LaGrange. 1971. Separation of mirex and PCB in fish. Laboratory Information Bulletin, U. S. Food and Drug Administration. New Orleans Dis- trict. (Unpublished). (7) Armour, J. A., and J. A. Burke. 1970. Method for sep- arating polychlorinated biphenyls from DDT and its analogs. J. Assoc. Off. Anal. Chem. 53(4): 761-768. Vol. 7, No. 2, September 1973 89 TABLE 1. — Residues of mirex and certain other chlorinated hydrocarbon insecticides in fat from beef cattle treated areas — 7970 Sample Sample Location Type OF Cattle RESroUES IN PPM Number Mirex Total DDT Others MISSISSIPPI 00158 Columbus Black Angus heifer 0.030 0.41 '0.52 00159 Fremont Spotted Jersey calf 0.005 0.165 - 00160 Artesia Angus-Holstein cross 0.016 0.020 10.64 00161 Artesia Angus-Holstein cross 0.035 5.0 - 00162 Artesia Hereford heifer 0.03 7.99 - 00163 Columbus Angus-Jersey cross 0.011 0.88 - 00164 Columbus Angus-Hereford cross 0.07 0.27 - 00165 Columbus Angus- Jersey cross 0.025 1.35 >0.48 00166 Columbus Whiteface heifer 0.01 0.271 - 00167 Columbus Whiteface steer 0.038 0.243 — 00168 Columbus Whiteface heifer 0.026 0.24 - 00169 Columbus Angus-Jersey cross 0.04 1.19 = 0.51 00170 Columbus Whiteface steer 0.02 0.159 - 00218 Starkville Jersey bull calf fatty tissue 0.029 0.245 - kidney - 0.007 — liver - 0.005 - 00219 Staikville Guernsey bull calf fatly tissue 0.024 0.314 - kidney 0.001 0.011 - liver — 0.006 — lean portion — 0.011 - 00220 Starkville Jersey bull calf fatty tissue 0.029 O.206 - kidney 0.002 0.005 - liver - 0.007 — lean muscle - 0.004 - 00292 Columbus Hereford-Jersey cross 0.005 0.838 - 00293 Baldwin Hereford 0.036 0.65 — 00294 Baldwin Angus 0.008 0.786 — 00295 Baldwin Angus 0.02 0.519 - 00296 Saltillo Angus bull 0.02 0.370 - 00297 Saltillo Angus steer 0.05 0.72 — GEORGIA 00267 Alma (Bacon Co.) Cow 0.018 0.429 — 00268 Ahna (Bacon Co.) Steer 0.005 0.121 — 00269 Nicholls (Coffee Co.) Steer 0.017 0.109 - 00270 Waycross (Ware Co.) Steer 0.003 0.046 - 00271 Dublin (Laurens Co.) Bull 0.002 0.131 - 00272 Dudley (Laurens Co.) Bull 0.041 3.906 — 00273 Dublin (Laurens Co.) Heifer 0.010 0.634 — 90 Pesticides Monitoring Journal TABLE 1. — Residues of mirex and certain other chlorinated hydrocarbon insecticides in fat from beef cattle in mirex- treated areas — 1970 — Continued Sample Sample Location Type OF Cattle Residues in Ppm Number Mirex Total DDT Others GEORGIA— Continued 00274 Dublin (Laurens Co.) Heifer 0.050 0.547 — 00275 Glenwood (Laurens Co.) Steer 0.041 2.081 — 00276 Forsyth (Monroe Co.) Dairy cow 0.013 0.102 - 00277 Forsyth (Monroe Co.) Dairy cow 0.002 0.063 - 00298 Patterson (Pierce Co.) Steer 0.020 0.127 - 00299 Screven (Wayne Co.) Heifer 0.001 0.160 i>0.11 00300 Waycross (Ware Co.) Steer 0.061 0.308 3 0.07 00301 Waycross (Ware Co.) Heifer 0.073 0.122 - 00302 Hoboken (Brantley Co.) Heifer 0.096 0.156 - 00303 Guyton (ESBngham Co.) Steer 0.028 0.091 — 00304 Guyton (Effingham Co.) Steer 0.040 0.120 — 00305 Guyton (Effingham Co.) Steer 0.033 0.11 — 00306 Guyton (Effingham Co.) Steer 0.060 0.075 - 00307 Savannah (Chatham Co.) Steer 0.013 0.081 — 00308 Hortense (BranUey Co.) Steer 0.002 1.685 — 00320 Statesboro (Bulloch Co.) Heitei 0.047 0.329 - 00321 Statesboro (Bulloch Co.) Heifer 0.169 - 00322 Statesboro (Bulloch Co.) Steer 0.010 0.138 - 00323 Statesboro (Bulloch Co.) Steer 0.015 0.367 - 00324 Millwood (Ware Co.) Steer 0.052 0.136 - 00325 Alma (Bacon Co.) Steer 0.125 0.469 - 00326 Cordele (Crisp Co.) Steer — 0.613 - 00327 Cordele (Crisp Co.) Steer — 0.446 "0.48 00328 Vienna (Crisp Co.) Steer - 0.910 - 00329 RocheUc (WUcoxCo.) Steer 0.017 1.921 = 0.52 00330 Statesboro (BuUochCo.) Cow 0.053 0.202 — 00331 Statesboro (Bulloch Co.) Steer 0.020 0.457 — 00472 Statesboro (Bulloch Co.) Steer 0.087 1.611 - 00473 Statesboro (Bulloch Co.) Steer 0.091 0.051 — 00474 Statesboro (Bulloch Co.) Steer - 0.037 - 00475 Statesboro (Bulloch Co.) Steer - 0.135 - 00486 Guyton (Effingham Co.) Steer 0.029 0.059 - 00487 Brooklet (Bulloch Co.) Steer 0.004 0.328 - 00488 Cordele (Crisp Co.) Steer 0.024 0.130 - 00489 Pincora (Chatham Co.) Steer - 0.081 — 00490 Savannah (Chatham Co.) Steer 0.016 0.281 - 00491 Pincora (Chatham Co.) Steer 0.003 0.256 — 00492 Statesboro (Bulloch Co.) Steer 0.002 0.074 - 00706 Atlanta (Fulton & DeKalb Co.) Steer 0.041 0.129 - 00707 Guyton (Effingham Co.) Heifer 0.040 0.286 - 00708 Savannah (Chatham Co.) Steer - 0.254 - 00709 Pincora (Chatham Co.) Steer 0.022 0.576 — Vol. 7, No. 2, September 1973 91 TABLE 1. — Residues of mirex and certain other chlorinated hydrocarbon insecticides in fat from beef cattle in mirex- treated areas — 1970 — Continued Sample Sample Location Type of Cattle Residues in Ppm Number Mirex Total DDT Others NOTE: — = not detected. 1 Aroclor 1254®. 2 Aroclor 1260®. 3 Technical chlordane. GEORGIA— Continued 00710 Statesboro (Bulloch Co.) Steer - 0.209 - 00711 Forsyth (Monroe Co.) Cow 0.020 1.472 - 00712 Guyton (Effingham Co.) Steer 0.023 0.171 - 00713 Gray (Jones Co.) Cow 0.032 0.118 - 00714 Haddock (Jones Co.) Cow 0.019 0.323 - 00715 Snarr (Monroe Co.) Cow — 0.054 — TABLE 2. — Residues of mirex and certain oilier chlorinated hydrocarbon insecticides in fat from beef cattle in areas out- side the mirex-treated region — 7970 Sample Sample Location Type OF Cattle Residues in Ppm Number Mirex Total DDT Others 00476 Iowa (11 — 0.02 — 00477 Iowa - - - 00478 Iowa - 0.06 - 00479 Iowa - — - 00480 Iowa - - - 00485 Iowa - 0.019 - 00481 Nebraska - 0.01 - 00482 Nebraska - 0.012 - 00483 Illinois - 0.119 - 00484 Nebraska Mississippi 0.022 00486 Batesville - 0.24 - 00847 Marks - n.43 - 00848 Batesville — 0.35 - 00849 Crowder — 0.32 - 00850 Pope - 0.18 - 00851 Como - 0.19 - 00852 Marks - 0.29 — 00853 Crowder — 0.042 - 00854 Helen — 0.26 — 00855 Charleston - 0.50 - 92 Pesticides Monitoring Journal TABLE 2. — Residues of mirex and certain other chlorinated hydrocarbon insecticides in fat from beef cattle in areas out- side the mirex-treated region — 1970 — Continued Sample Sample Location Type OF Cattle Residues in Ppm Number Mirex Total DDT Others South Carolina 00880 Darlington - 0.590 - 00881 Darlington - 0.703 - 00882 Darlington - 0.160 - 00883 Dillon - 0.530 - 00884 Dillon — 1.440 — 0O88S Darlington - 1.320 - 00886 Dillon Arkansas 5.800 00980 PoUard Heifer — 0.145 - 00981 Piggott Bull — 0.105 - 00983 PoUard Heifer — 0.620 — 00984 PoUard Heifer — 0.085 — 00985 Greene Co. Heifer — 0.220 — 00986 Paragould Bull — 0.038 - 00987 Greene Co. BuU — 0.190 — 00988 Paragould Bull — 0.190 — 00982 Fremont. Mo. Tennessee BuU 0.074 008S6 Union City Heifer — 0.067 — 00857 Dyersburg Heifer — 0.03 — 00858 Union City BuU — 0.058 = 0.11 00859 Union City Heifer — 0.051 — 00860 Union City Heifer — 0.06 — 00861 Dyersburg BuU — 0.054 — 00862 Dyersburg Heifer — 0.039 — 00863 Dyersburg BuU — 0.05 - 01024 LynnviUe Heifer — 0.04 — 01025 LynnvUle BuU - 0.043 — 01026 LynnvUle Heifer — 0.21 — 01027 LynnviUe Heifer - 0.16 — 01028 LynnviUe Georgia Heifer 0.20 — 01029 Washington Co. Bull - 0.95 — 01030 Social Circle Heifer — 0.06 — 01031 Social Circle BuU — 0.31 — 01032 Monroe Bull — 0.11 — 01033 Green Co. BuU - 0.35 — 01034 Rockdale Co. Heifer 0.01 0.08 — 01035 Walton Co. Bull — 0.21 — 01036 Eatonton Bull — 0.074 — 01037 Eatonton Bull — 0.056 _ 01038 Eatonton BuU - 0.106 - Vol. 7, No. 2, September 1973 93 TABLE 2. — Residues of mirex and certain other chlorinated hydrocarbon insecticides in fat from beef cattle in areas out- side the mirex-treated region — 1970 — Continued Sample Sample Location Type OF Cattle Residues in Ppm Number Mirex Total DDT Others North Carolina 01039 Mt. Olive Dairy cow — 0.78 - 01040 Mt. Olive Dairy cow — 0.42 — 01041 Beaulaville BuU — 0.55 — 01042 Beaulaville BuU — 0.30 — 01043 KenansviUe BuU — 0.29 — 01044 Burgaw Bull — 0.07 — 01045 Burgaw BuU — 0.04 — 01046 Willand Heifer — 0.11 — 01047 Wallace Bull — 0.98 — 01048 Wallace BuU — 0.31 — NOTE: — = not detected. ^ Blank = type of cattle unknown. 2 Aroclor 1254®. 94 Pesticides Monitoring Journal Residues of PCB's and PCT's in Canadian and Imported European Cheeses, Canada — 1972 David C. Villeneuve,' Lincoln M. Reynolds," and William E. J. Phillips' ABSTRACT Twenty Canadian and twenty imported European cheese samples were analyzed for PCB and PCT residues. The average PCB residue, determined on a whole-weight basis, in Canadian cheese was 0.042 ppm (range 0.01-0.27 ppm), while the average residue in imported cheese was 0.043 ppm {range 0.02-0.08 ppm). None of the cheese samples contained PCT residues at or above the detectable limit of the method (0.005 ppm). Introduction During 1972 an extensive survey was carried out to determine the levels of polychlorinated biphenyls (PCB's) and polychlorinated terphenyls (PCTs) in food packaging materials (i). Although cheese products were included in this survey, only a limited number of samples were obtained, and all were of the dr>' variety. Since none of these samples were packaged in material that contained — 10 ppm of PCB's or PCT's, no cheese sample was actually analyzed for PCB's or PCT's. The present survey, carried out in 1972, was designed to determine the PCB and PCT content of cheeses, both domestic and imported, that are available to the Ca- nadian consumer. 1 Food Research Laboratories, Health Protection Branch, Department of National Health and Welfare. Ottawa, Canada. 2 Ontario Research Foundation, Sheridan Park, Ontario. Sampling Procedures Samples of cheese representing 3 1 different companies were obtained by Health Protection Branch Inspectors in five centers across Canada: the Eastern region, repre- senting the Maritime Provinces, and the Quebec, On- tario, Manitoba, and Vancouver regions. Four domestic cheeses and four imported cheeses were selected from each region and were forwarded to the Ontario Research Foundation for analysis. The types of cheeses included the following: Cheddar, Mozzarella, Caciocavallo, Ri- cotta, Blue, Gouda, Fynbo, Tilsit, Havarti, Kasseri, Camembert, Semisoft, Lancashire, Butter, Esrom, Am- brosia, and Noekkelost. Analytical Procedures Analyses of the cheese samples for PCB's and PCT's were carried out as follows: The cheese sample (1-2 lb) was mascerated, and a 10-g representative aliquot, two tablespoons of anhydrous sodium sulfate, and 75 ml of 50% benzene in acetone were blended in a Sorval® mixer for 1 minute. The extract was filtered through a jacketed funnel with hot water being circulated to keep the fat in solution. The blender jar and filtering funnel were rinsed with benzene /acetone until 150 ml was collected. This solution was chilled in a dry ice/ methanol bath for 3 minutes and the flocculent precipi- tate obtained was filtered off through sodium sulfate rinsing with 50 ml of the benzene/ acetone solution. The filtrate was then concentrated and put through a Florisil Vol. 7, No. 2, September 1973 95 cleanup and then subjected to a "PCB split" (2). The GLC parameters for the determination of PCB and PCT residues are described elsewhere (/). Recoveries for PCB's and PCX's were 90% and 85%, respectively; results were not corrected for percent recovery. The limit of detection for both PCB's and PCTs was 0.005 ppm. Because low levels of PCB's were found, confirma- tion was not carried out. Results and Discussion The results obtained for Canadian cheese samples are shown in Table 1. Only one sample contained PCB's above 0.1 ppm, and the average content was 0.042 ppm (whole-weight basis). No cheese sample contained PCT's at or above the detectable limit of the method (0.005 ppm). The results obtained for imported cheese samples are shown in Table 2. No imported cheese sample con- tained PCB's above 0.1 ppm (average = 0.043 ppm) and as with the Canadian cheese samples, none con- tained any detectable amount of PCT's. LITERATURE CITED (;; Villeneuve, D. C, L. M. Reynolds, G. H. Thomas, and W. E. J. Phillips. 1973. Polychlorinated biphenyls and polychlorinated terphenyls in Canadian food packaging materials. J. Assoc. Off. Anal. Chem. 56(4): 999-1001. (2) Reynolds, L. M. 1971. Pesticide residue analysis in the presence of polychlorobiphenyls (PCB's). Res. Rev. 34:27- 57. TABLE 1. — Results of analyses for PCB's and PCT's in Canadian cheese samples TABLE 2.— Results of analyses for PCB's and PCTs in imported European cheese samples Residues in ppm, Whole-weioht Basis Sample Source PCB's PCT'S Montreal, Quebec 0.06 — 0.27 — 0.04 — 0.05 — Winnipeg, Manitoba 0.01 - 0.03 - 0.03 — 0.02 — Vancouver, British Columbia 0.02 — 0.02 - 0.04 — 0.01 — Charlottetown, Prince Edward Island 0.02 — 0.01 — Saint John, New Brunswick 0.04 — Halifax, Nova Scotia 0.05 — Toronto, Ontario 0.03 — 0.04 — 0.01 — 0.03 - Residues in ppm, Whole-weight Basis Country op Origin PCB's PCT's Denmark 0.03 — 0.04 - 0.05 — 0.03 — 0.03 — 0.03 — HoUand 0.02 - 0.05 — 0.04 — 0.08 — Greece 0.02 — France 0.06 — England 0.03 - 0.02 - West Germany 0.05 — 0.07 — Sweden 0.04 — Norway 0.05 — 0.05 — Switzerland 0.06 - NOTE: : Not detected at or above the limit of the method (0.005 ppm). NOTE: — = Not detected at or above the limit of the method (0.005 ppm). 96 Pesticides Monitoring Journal RESIDUES IN FISH, WILDLIFE, AND ESTUARIES Organochlorine Residues in Wild Moose, Idaho — 1972 ^ W. W. Benson, Michael Watson, and Joe Wyllie ABSTRACT In 1972, samples of adipose tissue from 14 moose, Alces alces shirasi, from the Targhee National Forest in eastern Idaho were analyzed by gas-liquid chromatography for organochlorine residues. Residues detected and respective mean levels for each were: p.p'-DDT, 52.3 ppb; p,p'-DDE, 28.9 ppb; p,p'-DDD, 53.0 ppb; a-BHC, 77.5 ppb; and diel- drin, 5.0 ppb. The presence of significant BHC levels in these animals probably reflects the prior use of BHC within the forest for control of pine bark beetle infestation. Introduction Pesticide residues and other contaminants continue to be found in many forms of wildlife. Although tissues from most of the wild North American ungulates of the deer family have been examined in detail for pesticide residue levels (7-6), there is little information regarding the extent of these contaminants in moose. To our knowledge, the only other report of pesticides in these animals is that of Walker et al. in 1965 (2) in which adipose tissues from three bull moose taken in central Idaho in 1962 were analyzed for DDT residues. This study reports organochlorine residues in the adi- pose tissue of 14 wild moose, Alces alces shirasi. taken during the 1972 hunting season in the Targhee National Forest in eastern Idaho. Several areas of the forest are infested with the mountain pine bark beetle. Dendroc- tonits ponderosii. and were sprayed from 1963 through 1 From the Idaho Community Study on Pesticides, Idaho Department of Environmental and Community Services. Statehouse, Boise, Idaho 83702. 1970 to control the infestation. This study was under- taken, as part of our wildlife monitoring program, in order to determine current body burdens of organochlo- rines in moose that may have resulted following the vari- ous spraying episodes. Sampling and Analytical Procedures Moose in Idaho are a protected species, occurring only in limited areas. TTiey are hunted only on a strictly controlled basis by means of special permits issued each fall by the Idaho Department of Fish and Game; in 1972. 2,923 hunters applied for the 120 available permits (1973, J. Graben, Idaho Dept. of Fish and Game, personal communication). Thus, sampling tech- niques were dependent on and limited to these circum- stances, and a more statistically desirable sampling pro- cedure was not possible. Although moose flesh is esteemed as table fare, they are primarily a trophy species; consequently, the large, ant- lered males are usually the animal of choice. To facili- tate proper game management, all successful hunters in Idaho are required to have their big game checked by the local conservation officer. Through the cooperation of the Idaho Fish and Game Department, samples of subcutaneous adipose tissue were obtained from 1 2 male and 2 female adult moose at checking stations in hunt- ing areas 60, 61, and 62 as established by the Depart- ment of Fish and Game. The kill locations were all within a 25-mile radius of one another and were almost entirely within the boundaries of the Targhee National Forest in Fremont County, Idaho. Tissues were col- lected during October 1972, transported immediately to the Idaho Community Study on Pesticides Laboratory in Boise, and frozen at — 4°C until analyzed in De- cember 1972. Vol. 7, No. 2, September 1973 97 Five-gram portions of each adipose tissue sample were extracted with petroleum ether and partitioned with acetonitrile according to the basic method of de Faubert Maunder et al. (7). Column cleanup on Florisil followed the procedure of Mills et al. (8, 9). Analysis was by means of a MicroTek 220 gas chromatograph, equipped with two differing columns and tritium foil electron capture detectors. This dual column technique was used in order to provide a reliable means of confirmatory analysis. In the case of a-BHC residues, all determina- tions were subjected to additional gas-chromatographic confirmation following TLC migration. TABLE 1. — Summary of organochlorine residues detected in moose adipose tissue, Idaho — 1972 Columns: 4% SE-30/6% QF-1 on 80/100 mesh Chromosorb W. DCMS 1.5% OV-17/1.95% QF-1 on 100/120 mesh Chromosorb W, DCMS Temperatures: Columns Injection chamber Detector 200° C 220° C 205° C Carrier gas: Nitrogen Carrier gas flow : On SE-30/QF-1 column On OV-17/QF-1 column 90 ml/min 70 ml/min This procedure, used extensively in our laboratory for several years, is easily capable of detecting pesticide residues in a 5-g sample at the parts per trillion (ppt) level. For convenience, however, any pesticide levels obviously less than one part per billion (ppb) were con- sidered negative. Percent recovery ranged from 82% to 100% and was based on the addition, prior to ex- traction, of a known amount of aldrin (Octalene®) to each sample as an internal standard. Results and Discussion The pesticide residues detected in the moose adipose samples are shown in Table 1 ; no polychlorinated biphenyls (PCB's) were noted in any of the samples tested. It is worthy of note that all residue levels de- tected are well below the minimum EPA tolerance levels for beef fat. P.p'-GDT and its metabolite p,p'- DDE were found in all 14 animals tested. P.p'-DDD was detected in only two samples. All but one of the moose had higher levels of p.p'-DDT than p.p'-DDE and the mean level for DDT (52.3 ± 7.0 ppb) was significantly higher than the mean DDE level (28.9 ± 5.7 ppb). This is consistent with previous findings in other wild members of the deer family (1-6). However, it is the reverse of the situation normally found in humans, in which DDE residues are usually considerably higher than are DDT levels (10). In our area, this trend has been well documented by recent large-scale monitor- ing of human tissues in both Idaho (11. 12) and Utah (13). It is possible that the different mode of digestion and intestinal flora of these wild ruminants are re- sponsible for this interesting variance. Residues in PPB Sampled Number Sex p.p'-DDT P.p'-DDE p,p'-DDD a-BHC DiELDRIN 1 M 19 20 8 — 2 2 M 131 98 98 — 24 3 M 44 26 — 115 5 4 M 33 19 — 33 5 5 M 46 19 — 57 5 6 M 47 20 — 56 — 7 M 47 26 — 48 2 8 M 56 32 — 64 1 9 M 73 35 — 130 2 10 M 38 16 — 124 — 11 M 53 22 — 124 3 12 M 62 41 — 71 — 13 F 41 13 - 47 2 14 F 42 17 — 61 4 Observed Range 112 85 90 97 22 Median 47 22 - 61 3 Mean ± S.E. 52,3 ± 7.0 28.9 ±5.7 53.0 ±17.0 77.5 ±9.4 5.0±1.7 NOTE: — = no residue detected; no polychlorinated biphenyl residues were detected in any samples. The widespread occurrence of a-BHC in the moose is also somewhat surprising. From 1963 through 1966 and subsequently from 1969, ethylene dibromide has been the chief insecticide used in the Targhee National Forest (1973, D. T. Fluckiger, Branch Chief, Targhee National Forest, personal communication). During 1967 and 1968, y-BHC (lindane), j8-BHC, and cacodylic acid were applied on a limited basis, but the use of BHC was discontinued in 1969 because of objectionable features. The sites treated with BHC during the 2-year period consisted of 31 campground areas comprising a total of 369 acres; a total of 96 lb. was applied. Although moose have been occasionally observed near the treated campground sites, such public areas are usually not frequented by the herd (1973, D. T. Fluckiger, Branch Chief, Targhee National Forest, personal communica- tion). Moreover, the vegetation types within the areas treated with BHC do not provide an abundance of forage for moose at any time of the year. However, since a large portion of the diet of these animals in their summer range consists of underwater vegetation, it is possible that additional pesticides were transmitted to these forage areas by adjacent runoff. In spite of these factors, the prior use of BHC for control of pine bark beetles is the only plausible explanation for its occur- rence. Perhaps even more perplexing is the occurrence of 98 Pesticides Monitoring Journal the alpha isomer of BHC in the moose, but not the yS- or the y- (lindane) forms. Since only /3- and y- BHC were sprayed, the occurrence of the alpha form in the animals is quite intriguing from a metabolic standpoint. Since 1965 the use of aldrin and dieldrin in Idaho has been restricted to certain specific purposes. In spite of this, dieldrin was detected in 11 of the 14 animals (Table 1). However, only one moose had adipose dieldrin concentrations that were appreciably high, suggesting that dieldrin is probably not a major body burden com- ponent within the herd. In 1965, the report of Walker et al. (2) found mean adipose DDT levels of 87 ppb and mean DDE levels of 10 ppb in three moose taken in 1962 from north central Idaho. These levels were slightly higher than our mean for DDT and slightly lower than our mean for DDE (Table 1), but higher DDT levels might be expected during those years of more extensive environmental DDT dispersal. A cknowledgments The authors gratefully acknowledge the efforts of Mr. Brent W. Ritchie, Game Research Biologist, Idaho De- partment of Fish and Game, in collecting moose samples. Special thanks for technical assistance are also expressed to Mrs. Leona Bousliman. This research was supported under Contract No. 68-02-0552 by the Division of Pesticide Community Studies, Office of Pesticide Pro- grams. Environmental Protection Agency, through the Idaho State Department of Environmental and Community Services. See Appendix for chemical names of compounds discussed in this paper. LITERATURE CITED (1) Pillmore, R. E., and R. B. Finley, Jr., 1963. Residues in game animals resulting from forest and range insecti- cide applications. Trans. N. Am. Wildl. Nat. Resour. Conf. 28:409-422. (2) Walker, K. C, D. A. George, and J. C. Maitlen. 1965. Residues of DDT in fatty tissues of big game animals in the states of Idaho and Washington in 1962. USDA Research Service ARS 33-105. 21 p. (3) Moore, G. L., Y. A. Greichus, and E. J. Hugghins. 1968. Insecticide residues in pronghom antelope of South Dakota. Bull. Environ. Contain. Toxicol. 3(5): 269-272. (4) Benson, W. W., and P. Smith. 1972. Pesticide levels in deer. Bull. Environ. Contam. Toxicol. 8(1): 1-9. (5) Greenwood, R. J., Y. A. Greichus, and E. J. Hugghins. 1967. Insecticide residues in big game mammals of South Dakota. J. Wildl. Mgmt. 31:288-292. {6) Baerckc. K. P., J. D. Cain, and W . E. Poc. 1972. Mirex and DDT residues in wildlife and miscellaneous samples in Miss ssippi— 1970. Peslic. Monit. J. 6(1): 14-22. (7) de Faiiberl Maunder. M. J.. H. E)>an. E. W. Godly, E. W. Hammond, J. Roburn, and J. Thomson. 1964. Clean-up of animal fats and dairy products for the analysis of chlorinated pesticide residues. Analyst 89: 168-174. (8) Mills, P. A. 1961. Collaborative study of certain chlori- nated organic pesticides in dairy products. J. Assoc. Oflf. Agric. Chem. 44:171-177. (9) Mills, P. A., J. H. Onley, and R. A. Gaither. 1963. Rapid method for chlorinated pesticide residues in nonfatty foods. J. Assoc. Off. Agric. Chem. 46:186-191. (10) Morgan, D. P., and C. D. Roan. 1971. Absorption, storage, and metabolic conversion of ingested DDT and DDT metabolites in man. Arch. Environ. Health 22: 301-308. (11) Watson, M., W. W. Benson, and J. Gabica. 1970. Serum organochlorine pesticide levels in people in Southern Idaho. Pestic. Monit. J. 4(2): 47-50. (12) Wyllie, J., J. Gabica, and W. W. Benson. 1972. Com- parative organochlorine pesticide residues in serum and biopsied lipoid tissue: A survey of 200 persons in Southern Idahti — 1970. Pestic. Monit. J. 6(2): 84-88. (13) Warnick, S. L. 1972. Organochlorine pesticide levels in human serum and adipose tissue, Utah — fiscal years 1967-71. Pestic. Monit. J. 6(1): 9-13. Vol. 7, No. 2, September 1973 99 Organochlorine Residues in Woodcock Wings, 11 States — 1970-71 M. A. R. McLane\ LucQle F. Stickel,' Eldon R. CIark,= and Donald L. Hughes^ ABSTRACT A survey of organochlorine residues in woodcock wings was undertaken to determine whether these wings are suitable for showing regional differences in residues and to obtain a baseline in 1970-71 for later comparisons. Woodcock wings were obtained from the annual hunter's wing survey. Samples came from eight States (Louisiana, Maine, Mich- igan, New Hampshire, New Jersey, New York, Pennsylvania, and Wisconsin) and one tri-State area (North Carolina, South Carolina, and Georgia). Wings from the tri-State area con- tained significantly higher (P'CO.Ol) concentrations of DDT (including DDT. DDD, and DDE) than those from other States. Concentrations of polychlorinated biphenyls (PCB's) also were significantly higher (P-CO.05) in samples from these three States. Wings from Louisiana and the tri-State area had significantly higher (P<^0.01) concentrations of dieldrin than wings from the other States, and those from Louisiana had significantly higher (P<^0.01) concentrations of mirex than those from other States. Introduction More than 1 million woodcock (Philohela minor) were harvested in the eastern United States during the 1970- 71 fall migrations (2). Because these birds subsist on animal material, primarily earthworms (5, 8), they can be used to measure pollution in an important terrestrial food chain. Their propensity to accumulate residues from their foods was clearly shown during the 1950's when heptachlor was used throughout the Southeast in an effort to control the imported fire ant (Solenopsis saevissima). Application of heptachlor to the land re- sulted in the widespread occurrence of heptachlor epoxide in the tissues of many species of birds, including woodcock (i, 7). Woodcock wintering in the South ac- cumulated residues from their food and carried them north with them in the spring (9). Residues declined following discontinuation of the program (6). The compounds detected and the ranges of residue means for all sampling areas were as follows: Total DDT (5.89 — 65.15 ppm): DDT (0.34 — 14.93 ppm); DDE (4.66 — 47.47 ppm): DDD (0.11 — 3.44 ppm); mire.x (0.76 — 16.93 ppm); diel- drin (0.09 — 3.06 ppm); and PCB's (4.27 — 8.63 ppm). The successful use of waterfowl wings to measure pesti- cide levels in black ducks {Anas ntbripes) and mallards (Anas platyrhynchos) (4) suggested the possibility that woodcock wings might be similarly employed. Woodcock wings appear to be suitable for determining regional differences in organochlorine residues in this species. ' Patuxent Wildlife Research Center, U. S. Bureau of Sport Fisheries and Wildlife. Laurel, Md. 20810. 2 Office of Migratory Bird Management, U. S. Bureau of Sport Fisheries and Wildlife, Laurel, Md. 20810. ^WARF Institute, Inc., Madison, Wis. 53701. Woodcock wings are obtained from hunters annually to evaluate the status and reproductive success of this species (2). The usefulness of wings in pesticide measure- ments was explored in 1970-71 by taking subsamples of these wings. This paper reports the results of this sampling. 100 Pesticides Monitoring Journal Methods Wing samples were taken from 1 1 States: Georgia, Louisiana, Maine, Michigan, New Hampshire, New Jersey, New York, North Carolina, Pennsylvania, South Carolina, and Wisconsin. These States were selected to include those that had the largest woodcock harvest and to include staites from both North and South. Wings from North Carolina, South Carolina, and Georgia were combined into one sample because there were too few wings to provide a sample from each State. Wings from each State and from the tri-State area were systematically sorted into groups of 25 for each State. Five of these groups were randomly selected for analysis from each State except for Louisiana and the tri-State area from which there were enough wings for only 4 groups. Wings were prepared for analysis by plucking the feathers and removing the distal joint. The remaining portion was ground in a hand grinder and homogenized in the groups of 25 that constituted the sample. A 20-g aliquot was taken for analysis. Analyses for organochlorine pesticides and polychlo- rinated biphenyls (PCB's) were made at WARF Institute, Inc., Madison, Wis., by the following procedures: This method detected organochlorines at a sensitivity level of 0.05 ppm. No corrections were made for re- coveries, which were 85% or better. Lipids were determined on an aliquot of the extract reduced to dryness on a steam bath and placed in a 40°C oven for 2-4 hours. All residues are expressed on a lipid-weight basis because the relative amounts of bone, feather, and moisture in the samples were uncontrolled variables. The presence of mirex was confirmed by mass spectrometry by W. L. Reichel at Patuxent Wildlife Research Center, Laurel, Md. Results and Discussion Table 1 shows the ranges and means for DDT, DDE, DDD, mirex, dieldrin, and PCB's for the eight States and the tri-State area. DDT and its metabolites exhibited the same overall pattern: The mean residues of DDT and each metabolite were significantly higher (P <0.01) in the tri-State area than in other States (DDT, 14.93 ppm; DDE, 47.47 ppm; and DDD, 3.44 ppm) and New Jersey woodcock wings contained the next highest con- centrations of these residues; DDT concentrations were significantly higher (P<0.01) than in other States, but DDE and DDD residues were not significantly higher (P<0.05). Figure 1 shows the overall pattern of the total DDT residues (including DDT, DDE, and DDD) in the States from which wings were analyzed. The 20-g aliquot was dried at 40°C for 72-96 hours, then ground with sodium sulfate and extracted with a mixture of ethyl and petroleum ether (30:70) for 8 hours in a Soxhlet apparatus. The extract was cleaned and separated into two fractions by elution through a Florisil column with mixtures of ethyl and petroleum ether (5:95 and 15:85). An aliquot of the first elution was passed through a standardized silicic acid column with petroleum ether, hexane, acetonitrile, and methy- lene chloride as described by Armour and Burke (/). Analysis was by electron capture gas chromatography on a Barber-Coleman Pesticide Analyzer Model 5360. In- strument conditions were: (1) Column, 4 ft. X 4 mm glass, packed with 5% DC- 200 on 80/100 mesh Gas Chrom Q; injector tem- perature 240°C, column 200°C, and detector 230°C; flow such that p.p'-DDT had a retention time of 6-8 minute. (2) Column, 4 ft. x 4 mm glass, packed with 3% OV- 17 and 100/120 mesh Gas Chrom Q; injector tem- perature 230°C. column 185°C, and detector 250°C; flow such that lindane had a retention time of 1 minute. The mean concentrations of dieldrin were significantly higher (P <0.01) in woodcock wings from Louisiana (2.37 ppm) and from the tri-State area (3.06 ppm) than in those from any of the northern States (Fig. 2). Wings from Louisiana and the tri-State area also had higher con- centrations of mirex (16.93 ppm and 4.08 ppm, respec- tively) although only those from Louisiana were sig- nificantly higher (P <0.01) than the others (Fig. 3). PCB's were found in all samples; the means ranged from 4.27 ppm in Maine to 8.63 ppm in the tri-State area. The PCS concentrations were significantly higher (P<0.05) in the tri-State area than all other States. The results of this sampling of wings of all populations of woodcock for organochlorine residues (DDT, DDE, DDD, mirex, dieldrin, and PCB's) indicate clear geo- graphic differences in residue levels. Woodcock wings api)ear useful for determining regional differences in organochlorine residues and for following their trends. See Appendix for chemical names of compounds discussed in this paper. Vol. 7, No. 2, September 1973 101 LITERATURE CITED (1) Armour, J. A., and J. A. Burke. 1970. Method for sep- arating polychlorinated biphenyls from DDT and its analogs. J. Assoc. Off. Anal. Chem. 53(4): 761-768. (2) Clark, E. R. 1971. The status of American woodcock — 1971. U. S. Bureau of Sport Fish, and Wildl., Migr. Bird Popul. Station Admin. Rep. p. 1-18. (3) DeWitt, J. B., C. M. Meuzie, V. A. Adomaitis, and W. L. Reichel. 1960. Pesticidal residues in animal tis- sues. Trans. 25th N. Am. Wildl. Nat. Resour. Conf. p. 277-285. (4) Heath, R. G. 1969. Nationwide residues of organochlo- rine pesticides in wings of mallards and black ducks. Pestic. Monit. J. 3(2): 115-123. (5) Krohn, W. B. 1970. Woodcock feeding habits as related to summer field usage in central Maine. I. Wildl. Manage. 34(4): 769-775. (6} McLane, M. A. R., L. F. Slickel, and J. D. Newsome. 1971. Organochlorine pesticide residues in woodcock, soils, and earthworms in Louisiana, 1965. Pestic. Monit. J. 5(3): 248-250. f7j Rosene, W., Jr., P. Stewart, and W. A. Adomaitis. 1962. Residues of heptachlor epoxide in wild animals. Proc. 5th Arm. Conf. Southeast, Assoc. Game Fish Comm. p. 107-113. (5) Sheldon, W. G. 1967. The book of the American Wood- cock. Univ. Mass. Press. Amherst. 227 p. (9) Wright, B. S. 1965. Some effects of heptachlor and DDT on New Brunswick woodcocks. J. Wildl. Manage. 29(1): 172-185. TABLE 1. — Organochlorines in woodcock wings from 11 states — 1970-71 REsmims IN PPM, LiPiD-WEiGHT Basis State Total DDT i DDT DDE DDD MiREX DiELDRIN PCB's Pennsylvania range 2.57-10.15 0.27-1.83 2.21-8.01 0.09-0,31 0.71-2.23 0.08-0.11 3.82-5.31 mean 6.49 1.06 5.23 0.19 1.14 0.10 4.67 New Hampshire range 3.45-25.18 0.55-3.61 2.84-21.20 0.06-0.36 0.42-1.46 0.10-0.19 4.45-7.39 mean 11.72 2.02 9.50 0.20 0.87 0.13 5.74 New York range 5.01-8.07 0.45-0.82 4.50-7.08 0.06-0.17 1.18-2.58 0.13-0.29 4.62-8.61 mean 6.41 0.65 5.64 0.12 1.77 0.20 6.87 Wisconsin range 3.60-21.96 0.27-0.52 3.28-21.21 0.05-0.23 0.62-2.40 0.06-0.30 3.79-14.34 mean 10.79 0.34 10.34 0.11 1.41 0.16 7.10 Maine range 3.59-10.19 0.48-1.48 3.03-8.40 0.08-0.31 0.57-2.24 0.06^.15 3.48-4.78 mean 5.89 1.02 4.66 0.21 1.34 0.09 4.27 New Jersey range 12.43-46.06 1.91-18.22 10.14-26.70 0.38-1.14 <0.05-1.38 0.26-2.33 2.71-8.09 mean 25.15 8.28 16.20 0.67 0.76 0.95 6.41 Michigan range 2.45-17.13 0.46-3.31 1.89-13.59 0.09-0.23 0.49-5.72 0.12-0.44 3.75-4.70 mean 8.98 1.16 7.67 0.15 1.93 0.30 4.30 Louisiana range 11.64-19.43 1.96-2.06 9.29-16.85 0.39-0.52 12.76-21.19 1.25-4.72 3.20-7.20 mean 15.45 2.02 12.98 0.45 16.93 2.37 5.44 North Carolina, South Carolina, Georgia range 34.40-108.70 8.57-21.12 22.86-83.22 2.97-4.36 0.60-8.01 1.17-4.98 6.99-10.20 mean 65.84 14.93 47.47 3.44 4.08 3.06 8.63 1 Total DDT includes DDT. DDD, and DDE 102 Pesticides Monitoring Journal FIGURE l.~Mean DDT residues (including DDT, DDD. and DDE) in woodcock wings (ppm, lipid weight basis) FIGURE 2. — Mean dieldrin residues in woodcock wings (ppm, lipid weight basis) FIGURE 3. — Mean mirex residues in woodcock wings (ppm, lipid weight basis) Vol. 7, No. 2, September 1973 103 Mirex Incorporation in the Environment: Residues in Nontarget Organisms — 1972 Syed M. Naqvi' and Armando A. de la Cruz" ABSTRACT A total of 78 samples representing 42 species of invertebrates, 3 species of fish, and 1 frog tadpole were randomly collected in 1972 from five sampling sites in Mississippi which had received varying degrees of mirex treatment. The samples were analyzed for mirex residues by gas chromatography. Residue levels in most samples were generally less than 1 ppm. Analyses of data provided observations on average residues (ppm) of pooled samples according to the following categories: (1) by type of organism — mollusks (0.15), fish (0.26), insects (0.29), crustaceans (0.44), and annelids (0.63); (2) by habitat— estuary (0.20), lake (0.27), grassland (0.28), creek (0.31), and pond (0.37); (3) by degree of mirex treat- ment at sampling site — legalized treatment on fire ant mound (0.12), no treatment (0.19-0.20). aerial treatment in 1972 (0.33), and aerial treatment in 1968-70 (0.38); and (4) by trophic level — herbivore (0.23), carnivore (0.30), and omni- vore (0.35). Mirex residues in animals collected from areas not treated with mirex suggest widespread movement of this pesticide in the environment, and the residues observed in the various trophic levels may be indicative of biological magnification. Introduction Mirex is a polycyciic chlorinated insecticide used in Mississippi and adjacent Southeastern States for control of the imported fire ant, Solenopsis saevissima — Forel 1 E)epartment of Biology, Alcorn A&M College, Lxirman, Miss. 39096. ' Department of Zoology, Mississippi State (jniversity, P. O. Drawer Z, Mississippi State, Miss. 39762. (2). In 1971, 4.5 million acres of open areas (non- woodland) were treated with fire ant bait by aerial ap- plication at the rate of 1.4 kg/ hectare (1.25 lb of 4X bait/ acre) which amounts to 4.2 g of the active in- gredient of mirex per hectare. This was done two to three times during the year (C. C. Fancher, Mississippi Dept. of Agriculture, Jackson, Miss., personal com- munication). Mirex is the active ingredient of a bait designated as 4X, 2X, and IX offered to fire ants. The 4X bait consists of 84.7% corncob grits, 15.0% soy- bean oil, and 0.3% mirex; 2X bait contains 0.15% mirex, and IX bait, 0.1% mirex. The presence of mirex residues in the tissues of a number of organisms reviewed by Alley (1) and our observations in the laboratory on the leaching of the toxic ingredient from the carrier bait and the ready uptake of this pesticide by aquatic invertebrates (4) prompted the routine analysis of residual mirex in nontarget organisms, particularly aquatic species. Al- though mirex is only slightly soluble in water, only about 1 ppb in fresh water and less in saline water (/), it could become potentially hazardous especially to detrivorous and neustonic organisms. No known metabolites of mirex have been reported in the literature. It is believed, however, that the toxicant is stored in quantities in animal tissues and is transported to all trophic levels in the food web. Theoretically, residue concentrations at- tain peak levels in the top consumers of the ecosystem. In this study, we are reporting the incorporation of mirex in the environment on the basis of residue levels in animals collected from various habitats in Mississippi. 104 Pesticides Monitoring Journal Methods and Procedures SAMPLE COLLECTION Animals were randomly collected from the following five sampling sites in Mississippi, four of which had received varying degrees of mirex treatment: Sampling site 1 — Noxubee Wildlife Refuge (Noxubee County) had received no mirex treatment; Sampling site 2 — Starkville (Oktibbeha County) had been treated by aerial applica- tion in 1968, 1969, and 1970 — since then, treatment has been limited to hand application on individual fire ant mounds esf)ecially during the summer; Sampling site 3 — Louisville-Noxapater site (Winston County) had been aerially treated during May and June 1972; Sampling site A — St. Louis Bay Estuary (Hancock County) had received no direct mirex treatment al- though the county was sprayed aerially in 1971; Sam- pling site 5 — Picayune (Pearl River County) had never been treated by airplane, but individual mound treat- ment has been in progress. All locations had been treated with 4X bait, except the Louisville-Noxapater site which had received IX bait. This history of mirex spraying was provided by the Agricultural County Agents of each county. The spyecimens on collection were cleaned of debris and mud when necessary, dipped quickly in acetone to re- move external contamination, air-dried, wrapped in aluminum foil, and stored frozen when not immediately prepared for mirex analysis. SAMPLE EXTRACTION AND CHROMATOGRAPHY Pooled whole body samples numbering from 2 to 350 individuals, depending on size, and weighing from 1.32 to 3.90 g, wet-weight basis, were extracted for residue analyses by grinding in 20 g of a 1:8 mixture of washed sodium sulfate and ignited sea-sand. Grinding was enhanced by adding 15 ml of nanograde hexane to the mixture. Ground sample, solvent, and sand were placed in a 60-ml widemouth bottle, shaken for 30 minutes on an Eberbach laboratory shaker, and the solvent decanted into a collection beaker. This process was repeated twice, each time using 20 ml of nanograde hexane and shaking for 15 minutes. The extract was evaporated to dryness under a fume hood at 24°C ± 3°C. Prior to gas-liquid chromatographic analysis (GLC), the extracts were cleaned by using activated alumina. The method used was a modification of de Faubert Maunder (3) for organochlorine compounds. In preparing the columns, the alumina and anhydrous sodium sulfate were washed twice with nanograde petroleum ether and finally with nanograde hexane. The alumina was activated by heating at 130°C for 12 hours and deactivated with 15% deionized distilled water. Five centimeters of deactivated alumina was placed into a 10 mm, OD X 30 cm fritted glass column. The adsorp- tion material was layered with 1 cm of anhydrous sodium sulfate and reactivated by heating for 3 hours at 130°C. Whole-body extract was added to the column in 2-ml volumes in six successive washes. Columns were eluted with 100 ml of hexane by successive 5-ml volumes, and the elutions were evaporated to near dry- ness. Tests were conducted to determine the amount of toxicant recovered by the extraction and cleanup tech- niques. Uncontaminated, whole-body samples were spiked with known amounts of mirex; recovery was 90-99%. Elution residues were diluted from 1 to 1,000 ml de- pending upon the concentration of mirex and analyzed on a Barber-Colman Model 5360 Pesticide Analyzer equipped with an electron-capture detector and a mixed column (6' X \Va") consisting of 1.5% OV-17 and 1.95% QF-1 on 80/100 mesh Chromosorb — WHP. Standard injection techniques were employed consis- tently for all samples. Operating parameters for the an- alyzer were as follows: column temperature, 217°C; nitrogen flow, 100 ml/min; and retention time for mirex, 27 minutes. Mirex quantification was done by peak height method according to the procedures of Gaul (4) and corrected for percent recovery. No con- firmatory procedure for mirex was used. Results and Discussion Mirex residues in 78 samples representing 42 species of invertebrates. 3 species of fish, and 1 frog tadpole are tabulated by sampling location in Table 1. The residue levels showed a great deal of variation but were generally below 1 ppm. As can be seen in Table 1, concentrations — 1 ppm were found in five samples, and > 2 ppm in only two samples. Higher concentrations have been detected in other species of nontarget organisms as re- viewed by Alley (/), but these species were primarily small vertebrates occupying the upper level in the food chain. Analysis, by trophic level, of residue concentra- tions pooled from all the sampling locations revealed average values of 0.23, 0.31, and 0.35 ppm for her- bivores, carnivores, and omnivores, respectively (Table 2). An investigation of biological magnification of mirex in the food chain as reflected by these values is being pursued in our continuing studies of mirex incorporation in the environment. Laboratory studies by Lowe et al. (7) and Ludke et al. (8) on the movement of mirex in simple food chains have shown that food items con- taining 0.5-1.0 ppm mirex caused up to 53% mortality in certain aquatic animals. If this were the case in na- ture, the residue levels detected in many of the orga- nisms examined in this study are potentially poisonous to prospective consumer species which are highly sensi- tive to mirex. Vol. 7, No. 2, September 1973 105 The ability of animals to concentrate mirex and other chlorinated hydrocarbons varies widely (4,7,9). This was indicated by the levels observed when the samples were pooled by taxonomic categories as shown in Table 3. The highest average residue concentration was detected in the annelids (0.63 ppm), while the lowest average concentration was observed in the mollusks (0.15 ppm). Earlier studies by Gish (6) showed that oligochaetes were able to concentrate large quantities of chlorinated hydro- carbons, and among this order of annelids, tubificids were noted by Naqvi and Ferguson (9) to be extremely tolerant. In our annelid samples, leeches contained fairly high levels of mirex. Residue averages, for animals pooled according to habitats and collection sites, are shown in Tables 4 and 5, respectively. Mirex residues in terrestrial organisms (e.g., grassland) are considered a result of the animals' direct contact with the pesticide, whereas mirex in samples from the four aquatic habitats is more a func- tion of the leaching of toxicant from the bait carrier and subsequent incorporation into the organisms. Lowe et al. (7) have shown in field experiments that 66% of the active ingredient leached out of the fire ant bait after 9 months. Our preliminary data obtained from laboratory simulations of leaching indicated 19% leach- ing after 15 days. Furthermore, the physical parameters of the habitat influence the accumulation of the pesticide. As can be seen in Table 4, the residue levels in enclosed small ponds were slightly higher than in free flowing creeks; levels in creeks were higher than in larger bodies of lakes; and levels in lakes were higher than in the more contiguous bay-estuary. The history of mirex application in the various sampling locations was discussed earlier in this report. As ex- pected, organisms from locations which received aerial treatment in conjunction with the fire ant control pro- gram had higher concentration levels than organisms from other areas (Table 5). The presence of residues in organisms from Bluff Lake (Noxubee County) and samples from St. Louis Bay Estuary (Hancock County) which did not receive any direct mirex treatment is evidence of the widespread movement of this compound in the environment. See Appendix for chemical name of mirex. A cknowledgment We thank Dr. James D. Yarbrough for the use of his GLC facility. Department of Zoology Physiology Lab- oratory, Mississippi State University. This work was supported by a USDA-ARS Cooperative Agreement No. 12-14-100-10, 935-33. LITERATURE CITED (1) Alley, E. G. 1973. The use of mirex in control of the imported fire ant. J. Environ. Qual. 2(1): 52-6L (2) Coon, D. W., and R. R. Fleet. 1970. The ant war. En- vironment 12(10): 28-38. (3) de Faubert Maunder, M. J. 1963. Clean-up (Sic) of animal fats and dairy products for the analysis of chlori- nated pesticides. Analyst 89:168. {4) de la Cruz, A. A., and Sycd M. Naqvi. 1973. Mirex in- corporation in the environment: uptake in organisms and effects on their rates of photosynthesis and respiration. Arch. Environ. Contam. Toxicol. 1(3). (5) Gaul, J. A. 1966. Quantitative calculation of gas- chromatographic peaks in pesticide residue analysis. J. Assoc. Off. Agric. Chem. 49:389-399. (6) Gish, C. D. 1970. Pesticides in soil. Pestic. Monit. J. 3(4): 241-252. (7) Lowe, J. /., P. R. Parrish, A. J. Wilson, Jr., and T. W. Duke. 1971. Effects of mirex on selected estuarine or- ganisms. Trans. 36th N. Amer. Wildl. Nat. Resour. Conf. March 7-10, 1971. Public Wildl. Manage. Inst. Wash- ington, D. C, 171-186. (8) Ludke, J. L., M. T. Finley, and C. Lusk. 1971. Toxicity of mirex to crayfish, Procambarus blandingi. Bull. En- viron. Contam. Toxicol. 6(1): 89-96. (9) Naqvi, S. M. Z., and D. E. Ferguson. 1968. Pesticide tolerances of selected freshwater invertebrates. Miss. Acad. Sci. 14:121-127. 106 Pesticides Monitoring Journal TABLE 1. — Mirex residues in nonlarget organisms collected at five sites in Mississippi, 7972 Species Collected and Habitat Basic Food Habit Mirex Residues in Scientific Name Common Name PPM », Wet- Weight Basis Total number of samples: 10 Average residue level; 0.19 ppm BLUFF LAKE in Noxubee Wildlife Refuge (Noxubee Co.. Miss.) » Lake: Neotettix proavus (Orthoptera: Insecta) Grasshopper Herbivore 0.10 Dichromorpha viridis (Orthoptera: Insecta) Grasshopper Herbivore 0.15 Gambusia affinis (PoeciUidae: Pisces) Mosquitofish Carnivore 0.07 Lepomis cyanellus (Centrarchidae: Pisces) Green sunfish Carnivore 0.12 Belostoma fiuminea (Hemiptera: Insecta) Giant water bug Carnivore 0.15 Lepomis cyanellus (Centrarchidae: Pisces) Green sunfish Carnivore 0.38 Dolomedes sexpunclatus (Pisauridae: Arachnida) Spider Carnivore 0.78 Campeloma subsidum (Gastropoda; Mollusca) Snail Omnivore 0.04 Palaemonetes kadiakensis (Decapoda: Crustacea) Freshwater shrimp Omnivore 0.06 Palaemonetes kadiakensis (Decapoda: Crustacea) Freshwater shrimp Omnivore 0.09 STARKVILLE AREA (Oktibbeha Co.. Miss.) » Pond: Neohydrophilus castus (Coleoptera: Insecta) Water scavenger beetle Herbivore 0.00 Tropisternus sp, (Coleoptera: Insecta) Water scavenger beetle Herbivore 0.36 Sigara alternata (Hemiptera: Insecta) Water boatmen Carnivore 0.03 Belostoma fiuminea (Hemiptera: Insecta) Giant water bug Carnivore 0.09 Notonecta undulata (Hemiptera: Insecta) Back swimmer Carnivore 0.13 Belostoma fiuminea (Hemiptera: Insecta) Giant water bug Carnivore 0.09 Neoperla clymene naiad (Odonata: Insecta) Dragonfly Carnivore 0.14 Erpobdella punctata (Hirudinea: Annelida) Leech Carnivore 0.24 Macromia magnifica naiad (Odonata: Insecta) Dragonfly Carnivore 0.31 Placobdella rugosa (Hirudinea: Annelida) Leech Carnivore 0.40 Macromia sp. naiad (Odonata: Insecta) Dragonfly Carnivore 1.92 Orconectes lancifer (Decapoda: Crustacea) Crayfish Omnivore 0.00 Vol. 7, No. 2, September 1973 107 TABLE l.—Mirex res dues in nontarget organisms collected at five sites in Mississippi, 7972— Continued Species Collected and Habitat Basic Food Habft MIREX Residues in Scientific Name Common Name PPM>, Wet- Weight Basis STARKVILLE AREA (Oktibbeha Co., M ss. ) ^ — Continued Physa gyrina (Gastropoda: MoUusca) Snail Omnivore 0.03 Physa gyrina (Gastropoda: Mollusca) Snail Omnivore 0.03 Limnodrilus udekemianus (Oligochaeta: Annelida) Aquatic earthworm Omnivoie 0.13 Physa gyrina (Gastropoda: MoUusca) Snail Omnivore 0.26 Procambarus hayi (Decapoda: Crustacea) Crayfish Omnivore 0.26 Palaemonetes kadiakensis (Decapoda: Crustacea) Freshwater shrimp Omnivore 1.08 Orconectes lancifer (Decapoda: Crustacea) Crayfish Omnivore 2.09 Lake: Hallplus Irlopsis (Coleoptera: Insecta) Crawling water beetle Herbivore 0.00 Helocordulia uhleria naiad (Odonata: Insecta) Dragonfly Carnivore 0.02 Gerris remigis (Hemiptera: Insecta) Water strider Carnivore 0.03 Macromia sp. naiad (Odonata: Insecta) Dragonfly Carnivore 0.67 Hyaltela azteca (Amphipoda: Crustacea) Sideswimmer Omnivore 1.33 Grassland: Dichrontorpha viridis (Orthoptera: Insecta) Grasshopper Herbivore 0.10 Neotettix proavus (Orthoptera: Insecta) Grasshopper Herbivore 0.24 Neotettix proavus (Orthoptera: Insecta) Grasshopper Herbivore 0.26 Conocephalus sp. (Orthoptera: Insecta) Grasshopper Herbivore 0.30 Dichromorpha viridis (Orthoptera: Insecta) Grasshopper Herbivore 0.70 Mimetus puritans (Mimetidae: Arachnida) Spider Carnivore 0.29 Total number of samples: 30 Average residue level : 0.38 ppm LOUISVILLE AND NOXAPATER AREAS (Winston C o.. Miss.) • Creek: Peltodyles sp. (Coleoptera: Insecta) Crawling water beetle Herbivore 0.12 Rana grylio tadpole (Anura: Amphibia) Frog Herbivore 0.12 Hexaginea bilineata larva (Ephemeroptera: Insecta) Mayfly Herbivore 0.90 108 Pesticides Monitoring Journal TABLE 1. — Mirex residues in nontarget organisms collected at five sites in Mississippi, 7972— Continued Species Collected and Habitat Basic Food Habit Mirex Residues in Scientific Name Common Name PPM 1, Wet- Weight Basis LOUISVILLE AND NOXAPATER AREAS (Winston Co., Miss.) «— Continued Progotnphus obscurus naiad (Odonata: Insecta) Dragonfly Carnivore 0.00 Lethocercus americanus (Hemiptera: Insecta) Giant water bug Carnivore 0.04 Progomphus obscurus naiad (Odonata: Insecta) Dragonfly Carnivore 0.04 Lethocercus americanus (Hemiptera: Insecta) Giant water bug Carnivore 0.09 HelocorduUa uhleri naiad (Odonata: Insecta) Dragonfly Carnivore 0.12 Plathemis lydia naiad (Odonata: Insecta) Dragonfly Carnivore 0.20 Lethocercus americanus (Hemiptera: Insecta) Giant water bug Carnivore 0.23 Erpobdella punctata (Hirudinea: Annelida) Leech Carnivore 1.76 Palaemonetes kadiakensis (Decapoda: Crustacea) Freshwater shrimp Omnivore 0.02 Physa gyrina (Gastropoda: MoUusca) Snail Onmivore 0.03 Orconecles mississippiensis (Decapoda: Crustacea) Crayfish Omnivore 0.10 Eupera singleyl (Pelecypoda: Mollusca) Clam Omnivore 0.1S Gammarus limneus (Ampliipoda: Crustacea) Sideswimmer Omnivore 0.42 Rhamphocorixa acuminata (Hemiptera: Insecta) Water boatmen Omnivore 2.01 Pond: Haliplus trtopsis (Coleoptera: Insecta) Crawling water beetle Herbivore 0.05 Enallagma sp. naiad (Zygoptera: Insecta) Damselfly Carnivore 0.07 Bueona elegans (Hemiptera: Insecta) Backswimmer Carnivore 0.10 Lepomis cyanellus (Centrarchidae: Pisces) Green sunfish Carnivore 0.17 Bueona elegans (Hemiptera: Insecta) Backswimmer Carnivore 0.22 Macromia sp. naiad (Odonata: Insecta) Dragonfly Carnivore 0.26 Gambusia affinis (Poeciilidae: Pisces) Mosquitofish Carnivore 1.00 Grassland ; Dichromorpha viridis (Orthoptera: Insecta) Grasshopper Herbivore 0.10 Total number of samples: 25 Average residue level : 0.33 ppm Vol. 7, No. 2, September 1973 109 TABLE 1. — Mirex residues in noiitarget organisms collected at five sites in Mississippi, 7972— Continued Species Collected and Habitat Basic Food Habit MmEX Residues in ScmNTiFic Name Common Name PPM', Wet- Weioht Basis PICAYUNE AREA (Pearl River Co., Miss.) '^ Creek: Lepomis cyanellus (Centrarchidae : Pisces) Green sunfish Carnivore 0.03 Gambusia affinis (Poeciilidae : Pisces) Mosquitoflsh Carnivore 0.12 Dineutes americanus (Coleoptera: Insecta) Whirligig beetle Carnivore 0.22 Noturus funebris ( Ictaluridae : Pisces) Catfish Carnivore 0.32 Palaemonetes sp. (Decapoda: Crustacea) Shrimp Omnivore 0.00 Palaemonetes sp. (Decapoda: Crustacea) Shrimp Omnivorc 0.02 Total number of samples : 6 Average residue level: 0.12 ppm ST. LOUIS BAY ESTUARY (Hancock Co., Miss.) « Estuary: Crassostrea virginica (Pelecypoda: Mollusca) Oyster Omnivore 0.07 Crassostrea virginica (Pelecypoda: Mollusca) Oyster Omnivore 0.11 Marginella apicina (Gastropoda: Mollusca) Snail Omnivore 0.19 Polymesoda caroliniana (Pelecypoda: Mollusca) Clam Omnivore 0.19 Uca sp. (Decapoda: Crustacea) Crab Omnivore 0.21 Crassostrea virginica (Pelecypoda: Mollusca) Oyster Omnivore 0.24 Littorina anguilifera (Gastropoda: Mollusca) Snail Omnivore 0.41 Total number of samples; 7 Average residue level: 0.20 ppm * Residue values represent single analysis of a pooled sample numbering from 2 to 350 individuals, depending on size, and weighing from 1.32 to 3.90 g. - This area had not received any mirex treatment of any kind. ^ This area received the prescribed aerial treatment of mirex in 1968. 1969. and 1970. * These areas were treated with the prescribed dosage of mirex in summer 1972. ^ This area has never been aerially treated with mirex. but individual mound treatment has been initiated. "This area had never received mirex treatment directly, but Hancock County was sprayed aerially in 1971. 110 Pesticides Monitoring Journal TABLE 2. — Mirex residues in organisms grouped according to trophic levels TROPHIC Number of Samples Mirex Residues in PPM, Wet-weight Basis Level Range Median Mean Herbivores Carnivores Omnivores 15 36 27 0-0.90 0-1.92 0-2.09 0.12 0.15 0.13 0.23 0.30 0.35 TABLE 3 — Mirex residues in organisms grouped according to taxonomic categories Trophic Number of Samples Mirex Residues N PPM, Wet-weight Basis Level Range Median Mean Mollusca 12 0.03-0.41 0.13 0.15 Pisces and Amphibia 9 0.03- 1.00 0.12 0.26 Insecta and Arachnida 40 0-2.01 0.14 0.29 Crustacea 13 0 - 2.09 0.10 0.44 Annelida 4 0.13-1.76 0.32 0.63 TABLE 4. — Mirex residues in organisms grouped according to habitat Number of Mirex Residues in PPM, Wet-weight Basis Pooled Samples Habitat Range Median Mean Estuary 7 0.07 - 0.41 0.19 0.20 Lake 15 0-1.33 0.10 0.27 Grassland 7 0.10-0.70 0.26 0.28 Creek 23 0-2.01 0.12 0.31 Pond 26 0 - 2.09 0.16 0.37 TABLE 5 — Mirex residues in organisms grouped according to sampling sites Sampling SUES' Number of Samples Mirex Residues in PPM, Wet-weight Basis Range Median Mean Picayune, Pearl River County 6 0-0.32 0.08 0.12 St. Louis Bay Estuary, Hancock County 7 0.07-0.41 0.19 0.19 Noxubee Refuge, Noxubee County 10 0.04 - 0.78 fl.ll 0.19 Louisville and Noxapater, Winston County 25 0- 2.01 0.12 0.33 Starkville, Oktib- beha County 30 0 - 2.09 0.24 0.38 ' Picayune received individual mound treatment; St. Louis Bay Estuary and Noxubee Refuge did not receive any form of mirex application; Louisville-Noxapater was aerially treated in 1972; and Starkville re- ceived several aerial treatments since 1968. Vol. 7, No. 2, September 1973 111 Accumulation of Mir ex Residues in Selected Organisms After an Aerial Treatment, Mississippi — 1971-72 James L. Wolfe' and B. R. Norment" ABSTRACT Mirex residues were monitored in selected organisms in Mattubby Creek Watershed, Monroe County, Miss., for approximately 1 year following an aerial application of IX mirex bait (0.85 g/acre). Although thi-re was an iicrpise in residues in crayfish, levels remained relatively low in in- vertebrates as compared to those previously reported. Fishes from streams in the treated areas showed an increase in residues of about 2 to 20 times over controls taken from an adjacent watershed. These levels in stream fishes remained relatively constant for 7 months after treatment, when the last sample was taken. Residue levels in mammals were obviously stratified according to food habits. Strict herbivores had the lowest levels, omnivores intermediate levels, and insectivore-carnivores the highest levels. Generally, the residues detected were lower than those previously reported and presumably reflected the lower rate of mirex application (IX rate versus the normal 4X or 2X rate). The fact that the compound was concentrated by certain non target or- ganisms even at this low rate of application and stratified by trophic level is worthy of note. Introduction Environmental pollution is one of the most pertinent and controversial issues today. Chlorinated hydro- carbon pesticides are some of the most frequently men- tioned offenders, chiefly because of their long residual properties and their accumulation by plants and animals in the food chain of man (9). Currently, a stable chlori- nated hydrocarbon pesticide, mirex, is being used in the 1 Department of Zoology, Mississippi Stale University, Mississippi State, Miss. 39762. = Department of Entomology, Mississippi Agricultural and Forestry Experiment Station, Mississippi State University, Mississippi State, Miss. 39762. Southern United States in efforts to control the spotted imported fire ant, Solenopsis saevissima richteri (Forel), and the imported fire ant, Solenopsis invicta (Buren); and a control program is being implemented to treat large areas in Mississippi with mirex bait. In 1971-72, this study of selected aquatic and terrestrial vertebrate and invertebrate populations from the Mattubby Creek Watershed, Monroe County, Miss., was initiated to de- termine the extent of mirex residues in a freshwater ecosystem following an aerial application of mirex. Val Valin et al. {10) reported that at the recommended rate, the concentration of mirex residues in soil, water, and vegetation was relatively constant for over 300 days. Other studies {1,3,4) have shown that the acute toxicity of mirex to birds and mammals is extremely low. Simi- larly, low toxicity to fishes has been recorded {2,5). Chronic effects of sublethal levels have not been in- vestigated in any detail and these may be important because the chemical is persistent. Its high toxicity to nontarget arthropods, especially Crustacea, has been demonstrated in the laboratory by Lowe et al. (5) and Ludke et al. (6). Study Area The Mattubby Creek Watershed of Monroe County, Miss., was selected for study. This area was last treated with mirex in 1968 as was most of east-central Missis- sippi. After pretreatment sampling in the summer and early fall of 1971, the area received an aerial application of IX mirex bait on Sept. 15, 1971. Organisms for residue analysis were collected from per- manent and temporary ponds, streams, and terrestrial 112 Pesticides Monitoring Journal habitats. A 1-acre permanent pond east of Lake Monroe (about 7 miles north of Aberdeen) was used extensively for collecting and exposing caged catfish. Two temporary pools approximately 3 miles south of this pond were also used for collecting. Streams sampled in the treat- ment area included Mattubby Creek, Wolf Creek, and Cedar Creek. Control streams in an adjacent watershed which was not subjected to the 1971 treatment were Kettle Creek, James Creek, and Nichols Creek. A number of terrestrial areas, primarily old fields in early successional stages, in a quadrangle 7 miles north and west of Aberdeen were sampled. Sample Collection INVERTEBRATES Invertebrates collected consisted of crayfish (Orconectes sp.), mosquito larvae (mixed species), and field crickets (Acheta assimilis). Pre- and post-treatment samples of all three organisms were obtained and analyzed at ap- proximately regular intervals over a 12-month period. Crayfish were collected from the permanent and the two temporary ponds; mosquito larvae were collected from temporary pools. The cricket samples all came from a single field locality. POND FISHES Two species were analyzed from the permanent pond. Channel catfish, Ictalunis punctaiiis (80, 3-inch finger- lings in a wire cage and 2,000 released as 1-inch finger- lings), were placed in the pond. Naturally occurring green sunfish (Lepomis cyanelliis) were seined from the pond. Fish samples were analyzed at the same intervals as were the invertebrates. STREAM FISHES A total of 10 species of stream fishes were analyzed for mirex residues (Table 2). No pretreatment samples were taken, but concurrent samples were taken from streams in an adjacent, untreated (since 1968) drainage area. Collections for analysis were made by seining in November 1971 and April 1972. MAMMALS Seven species of small mammals were captured and analyzed. These included the cotton rat (Sii;modon hispidus), the rice rat (Oryzomys palustris). the harvest mouse (Reithrodontomys humiiUs). the pine mouse (Pitymys pinetorum), the wood mouse (Peromysciis leucopus), the house mouse (Miis musculus). and the short-tailed shrew {Blarina brevicauda). Collections were made in September (prior to treatment), December 1971, and March and May 1972. Animals were captured alive in Sherman traps. Sample Preparation and Analytical Procedure Invertebrates and fishes were packed in ice in the field and frozen on arrival at the laboratory. Mammals were brought in alive and then frozen. Residues given are on a whole-body basis unless otherwise stated. In the case of invertebrates and fishes, several specimens were pooled and homogenized to make a sample. For the mammals, one specimen equals one sample. All analyses were performed by the Mississippi State Chemical Laboratory using standard FDA procedures for biological materials (7). The one departure from the referenced procedure was that two extractions rather than the recommended one were used. Previous work on fish and bird samples by the laboratory involving exhaustive (6 to 9) extrac- tions indicated that two extractions removed from 90 to 95% of the mirex from the sample. A Barber-Coleman (Model 5360) Pesticide Analyzer with a Ni^'' detector was used for the analyses. A mixed column, OV-210/ OV-1, was used for quantitation and a DEGS column for confirmation. The sensitivity of the method was ap- proximately 0.01 ppm. Results and Discussion Residue data for invertebrates are given in Table 1. In crayfish, no residues were detected in 2 pretreatment samples, but residues averaging 0.07 ppm were de- tected in all 8 posttreatment samples. In insect samples, there was no clear indication of an increase in residue levels during the posttreatment period. Levels for both crickets and crayfish were lower than those reported after one treatment by Markin et al. (8). Samples of green sunfish taken from the permanent pond in July and August each contained 0.02 ppm mirex. A sample taken on September 22. just after the aerial ap- plication, had 0.01 ppm. Samples collected from No- vember through February did not contain detectable mirex levels; no sunfish were found from April through July. A pretreatment catfish sample taken in early Sep- tember did not contain mirex. Residues in three post- treatment samples of the caged /. punctatus fingerlings taken in September, October, and November ranged from O.OI to 0.02 ppm. In January the caged finger- lings were gone (had apparently died and decomposed), and none were captured on six subsequent seining trips. On November 2. differences in residues were apparent in fish species taken from untreated and treated streams (Table 2). Mosquitofish {Gamhiisia affinis) from un- treated streams averaged about 0.05 ppm, whereas those from treated areas averaged 0.54 ppm. While there was little difference in the top minnow samples from the two areas, residues in the Cyprinid, Noiropis hellus. a pretty shiner, from the treated area were considerably higher than those from the untreated area (0.30 vs. 0.06 ppm). A redfin pickerel (Esox americanus americanus), pre- VoL. 7, No. 2, September 1973 113 sumably a top carnivore, from fhe treated area had a residue of 0.53 ppm. None were collected from an untreated stream on this trip, but in April one collected from an untreated area had 0.02 ppm. the possibility thaT mirex levels were more localized and that the residues detected in the specimens during the posttreatment period were due to the September 1971 application. Five months later (April 26), the situation appeared relatively unchanged. Previously, the highest level de- tected, 0.92 ppm, was in a mosquitofish, a topwater form. In April the highest residues (0.97, 1.02 ppm) were found in Cyprinids (shiners), which are primarily mid-water forms. Typically, species or groups from treated areas showed increases in mirex residues of 2 to 10 times over those from untreated areas (Table 2). A sample of small mammals (cotton rats, rice rats) collected in the Mattubby Creek watershed on Sept. 4, 1971, showed extremely low mirex residues. No residues were detected in cotton rats, while small amounts (0.01 ppm) were detected in rice rats. In December, residues of 0.02 were detected in house mice (Table 3). In March, cotton rats had residues as high as 0.02 ppm which was not a significant increase, but two species of mice (harvest mice and white-footed mice), which are similar to rice rats and house mice in food habits, had levels as high as 0.54 ppm. On this date the first collection of shrews was also made. Shrews, which eat primarily in- vertebrate animals and occasionally small vertebrates and from which the highest mirex residue of any mam- mal has been reported, Markin et al. ( 0.09 0.05 0.04 0.05 0.04 Mosquito larvae 0.00 0.00 0.00 0.00 0.00 0.03 0.02 0.00 0.00 Field cricket (Acheta assimilis ) 0.00 0.00 0.03 0.00 0.02 0.01 0.00 0.00 0.02 0.03 NOTE: Blank = no sample collected; several specimens were pooled and homogenized to make a sample; residues reported are on a whole-body basis unless otherwise indicated. ' Average of three samples (0.02 - 0.22 ppm) . TABLE 2. — Mirex residues in stream fislies before and after treatment of the Mattubby Creek Waterslied in Monroe County, Miss.— 1971-72 Residues in PPM Untreated Streams Treated Streams Species November 1971 April 1972 November 1971 April 1972 Number IN Sample Mean Range Number IN Sample Mean Range Number IN Sample Mean Range Number IN Sample Mean Range Redfin pickerel (Esox americanus amerkanus) 1 0.02 1 0.53 Pretty shiner (Notropis bellus) 1 0.06 2 0.29 (0.04- 0.55) 3 0.41 (0.10- 0.97) Blacktail shiner (N. venuslus) 1 0.03 1 0.22 Bluntnose minnow {Pimephales notatus) 2 0.76 (0.51- 1.02) Top minnow (Fundulus sp.) 1 0.01 1 0.02 1 0.03 2 0.08 (0.07- 0.10) Mosquitofish {Gambusia affinis) 3 0.04 (0.00- 0.06) 1 0.04 2 0.53 (0.15- 0.92) 5 0.15 (0.04 0.26) Green suofish {Lepomis cyanellus ) 1 0.00 2 0.10 (0.05- 0.15) 1 0.03 Blue gill (L. Macrochirus) 3 0.02 (0.01- 0.04) 1 0.02 2 0.01 (0.01- 0.02) 1 0.11 Largemouth bass (Micropterus salmoides ) 1 0.05 1 0.18 Darter {Etheostoma sp.) 1 0.02 2 0.04 NOTE; Each sample was taken from a different stream; Blank = no sample collected. Vol. 7, No. 2, September 1973 115 TABLE 3.- — Mirex residues in small mammals collected in Monroe County, Miss., Sept. 4, 1971-March 22 and May, 1972 RESiDtms IN PPM Species September 4 December 21 March 22 and May Number IN Sample Mean Range Number IN Sample Mean Range Number IN Sample Mean Range Cotton rat (Sigmodon hispidus ) 6 0.00 2 0.00 2 0.01 (0.01- 0.02) Rice rat (Oryzomys paluslris) 2 0.00 (0.00- 0.01) 3 0.00 (0.00- 0.01) House mouse (Mus musculus) 3 0.01 (0.00- 0.02) Harvest mouse (Reithrodontomys humulis) 1 0.54 Wood mouse (Peromyscus leucopus} 5 0.15 (0-04- 0.21) Pine mouse (Pitymys pinetorum) 1 0.02 Short-tailed shrew (Blarina brevicauda) 5 1.00 (0.10- 1.89) NOTE: Blank = no sample collected. TABLE 4. — Relationship of diet to mirex residues in small mammals collected in treated area of Monroe County, Miss. 1972 TROPHIC Level Mirex Residues in PPM " Herbivores 0.01 (Feed principally on plants — Sigmodon. Pitymys) Omitivores 0.21 (Feed principally on plant products and invertebrates — Oryzomys, Peromyscus, Reithrodontomys ) Carnivores 1.00 (Feed principally on invertebrates with some vertebrate material — Blarina ) TABLE 5. — A comparison of whole body and tissue levels of three species of small mammals collected from the treated area of Monroe County, Miss., March 17-19, 1972 ' Data taken from specimens collected on March 22, 1972. Sample No. Residues IN PPM Species Whole Body Muscle Brain Liver Sigmodon 1 2 0.00 0.00 3 n.oo 0.00 0.04 4 0.00 0.00 0.01 5 0.00 0.00 0.01 6 0.01 0.00 0.02 7 0.00 0.00 0.03 Oryzomys 1 0.24 2 0.09 0.17 1.75 3 0.20 0.16 2.45 Blarina 1 0.26 2 0.25 0.10 0.42 116 Pesticides Monitoring Journal APPENDIX Chemical Names of Compounds Discussed in This Issue BHC DDE DDT DIELDRIN MI REX POLYCHLORINATED BIPHENYLS (PCB's) TDE (DDD) (including its isomers and dehydrochlorina- tion products) 1, 2,3,4, 5,6-hexachlorocyclohexane, mixed isomers l,l-dichloro-2,2-bis(p-chlorophenyl) ethylene l,l,l-trichJoro-2,2-bis(p-chlorophenyl)ethane, technical DDT consists of a mixture of the p,p'-isomer and the o.p'-isomer (in a ratio of about 3 or 4 to 1 ) Not less than 85% of l,2,3,4,10,10-hexachloro-6,7-epoxy-l,4,4a,5.6,7,8,8arOctahydro-l,4-?ndo-eJ:o-5,8-dimethano= naphthalene dodecachlorooctahydro-l,3,4-metheno-2fl'-cyclobuta[cJ]pentalene Mixtures of chlorinated biphenyl compounds having various percentages of chlorination l,l-dichloro-2,2-bis(p-chlorophenyl)ethane; technical TDE contains some o.p'-isomer also Vol. 7, No. 2, September 1973 117 Information for Contributors The Pesticides Monitoring Journal welcomes from all sources qualified data and interpretive information which contribute to the understanding and evaluation of pesticides and their residues in relation to man and his environment. The publication is distributed principally to scientists and technicians associated with pesticide monitoring, research, and other programs concerned with the fate of pesticides following their application. Additional circulation is maintained for persons with related in- terests, notably those in the agricultural, chemical manu- facturing, and food processing industries; medical and public health workers; and conservationists. Authors are responsible for the accuracy and validity of their data and interpretations, including tables, charts, and refer- ences. Accuracy, reliability, and limitations of the sam- pling and analytical methods employed must be clearly demonstrated through the use of appropriate procedures, such as recovery experiments at appropriate levels, confirmatory tests, internal standards, and inter-labora- tory checks. The procedure employed should be ref- erenced or outlined in brief form, and crucial points or modifications should be noted. 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C. 20460. 118 Pesticides Monitoring Journal The Pesticides Moniloriiii; Journal is published quarterly under the auspices of the FEDERAL WORKING GROUP ON PEST MANAGEMENT (responsible to the Council on Environ- mental Quality) and its MONITORING PANEL as a source of information on pesticide levels relative to man and his environment. The WORKING GROUP is comprised of representatives of the U. S. Departments of Agricul- ture; Commerce; Defense; the Interior; Health, Education, and Welfare; State; Transportation; and Labor; and the Environmental Protection Agency. The pesticide MONITORING PANEL consists of representatives of the Agricultural Research Service, Consumer and Marketing Service. Extension Service, Forest Service, Department of Defense, Fish and Wildlife Service. Geological Survey, Food and Drug Administration, En- vironmental Protection Agency. National Marine Fisheries Service. National Science Founda- tion, and Tennessee Valley Authority. Publication of the Pesticides Monitoring Journal is carried out by the Technical Services Division of the Environmental Protection Agency. Pesticide monitoring activities of the Federal Government, particularly in those agencies repre- sented on the pesticide MONITORING PANEL which participate in operation of the national pesticides monitoring network, are expected to be the principal sources of data and interpretive articles. However, pertinent data in summarized form, together with interpretive discussions, are invited from both Federal and non-Federal sources, including those associated with State and community monitoring programs, universities, hospitals, and nongovernmental research institu- tions, both domestic and foreign. Results of studies in which monitoring data play a major or minor role or serve as support for research investigation also are welcome; however, the Journal is not intended as a primary medium for the publication of basic research. Manuscripts received for publication are reviewed by an Editorial Advisory Board established by the MONITORING PANEL. Authors are given the benefit of review comments prior to publication. Editorial Advisory Board members are: John R. Wessel, Food and Drug Administration, Chairman Paul F. Sand, Agricultural Research Service, Vice Chairman Anne R. Yobs, Center for Disease Control William F. Durham, Environmental Protection Agency Thomas W. Duke, Environmental Protection Agency G. Bruce Wiersma. Eiivironnnnicil Prolcciion Agency William H. Stickel, Fish and Wildlife Service Milton S Schechter, Agricultural Research Service Herman R. Feltz, Geological Survey Mention of trade names or commercial sources in the Pesticides Monitoring Journal is for identification only and does not represent endorsement by any Federal agency. Address correspondence to: Paul Fuschini Editorial Manager PESTICIDES MONITORING JOURNAL U. S. Environmental Protection Agency Room 349 East, Waterside Mall 401 M Street, S.W. Washington, D. C. 20460 CONTENTS Volume 7 March 1974 Number 3/4 Page EDITORIAL 121 PESTICIDES IN PEOPLE Organoclilorine Pesticide and Polyclilorinaled Biplicnyl Residues in Biopsied Human Adipose Tissue — Texas, 1967-72 122 James E. Burns RESIDUES IN FOOD AND FEED Surveys of Mercury Levels in Fisli and Other Foods 127 Robert E. Simpson, William Horwitz. and Caesar A. Roy Levels of Mirex and Some Other Organoclilorine Residues in Seafood from Atlantic and Gulf Coastal Slate' 139 G. P. Markin, J. C. Hawthorne. H. L. Collins, and J. H ;-ord RESIDUES IN FISH. WILDLIFE. AND ESTUARIES Mirex Residues in Selected Estuaries of South Carolina — Jiiiie 1972 144 P. W. Borthwick. G. H. Cook, and J. M. Patrick. Jr. Monitoring 2,4-D Residues at Loxahatchee National Wihilifc Refuge 146 Donald P. Schiiltz and Eugene W. Whitney Nationwide Organoclilorine and Mercury Residues in IVings of Adult Mallards and Black Ducks During 1969-70 Hunting Season 15.3 Robert G. Heath and Sharon A. Hill Organoclilorine Insecticide Residues in Sediment and Fish Tissues, Ontario, Canada — . 165 R. Frank, A. E. Armstrong. R. G. Boelens, H. E. Braun, and C. W. Douglas Relations of the Brown Pelican to Certain Environmental Pollutants 181 Lawrence J. Blus. Andre A. Belisle. and Richard M. Prouty Residues of Organoclilorine Pesticides, Mercury, and PCB's in Mourning Doves from Eastern United States, 1970-71 195 J. F. Kreitzer PESTICIDES IN SOIL DDT Residues in Soil, Water, and Fauna from New York Apple Orchards 200 R. J. Kuhr, A. C. Davis, and J. B. Bourke GENERAL Chlorinated Insecticide Residues in Kentucky Burley Tobacco: Crop Years 1963-72 205 James R. Gibson, George A. Jones, H. Wyman Dorough. Christina I. Lusk. and Richard Thurston BRIEF Mercury Levels in Soils of the Eastern United States 214 G. B. Wiersma and H. Tai APPENDIX Chemical names of compounds discussed in tliis issue 217 ACKNOWLEDGMENT . 218 ANNUAL INDEX (VOLUME 7, JUNE 1973 - MARCH 1974) Preface 219 Subject index 220 Author index 222 EDITORIAL A Tribute to Sylvia O'Rear and Her Staff Self-praise is seldom viewed with admiration. For a special reason, however, the Editorial Advisory Board feels it is appropriate to boast momentarily about the success of the Pesticides Monitoring Journal. Specifi- cally, the reason is to pay tribute to Sylvia O'Rear, former PMJ Editorial Manager, and to members of her staff, particularly Lynn Herring and Priscilla Holman, technical editors. As a result of recent organizational changes within the U.S. Environmental Protection Agency, the function of the Editorial Manager has been transferred from Cham- blee, Georgia, to Washington, D.C. However, Mrs, O'Rear and her staff were unable to come to Washing- ton. Because these individuals' contributions to the Journal have been outstanding, the Monitoring Panel and the Editorial Advisory Board unanimously decided to dedicate this issue of the Journal to them. Perhaps the most fitting tribute that could be given this staff is a statement on the accomplishments of the Journal. Although the publication is relatively young, it has in a little over six years achieved national and in- ternational recognition as evidenced by the large num- ber of worldwide subscribers. In addition, with each new issue of the Journal it becomes more evident that non-Federal sources, as well as foreign sources, are providing an increasing number of papers for publica- tion. We believe these facts are an indication that the Journal has become one of stature in its field and that Mrs. O'Rear and her staff played a major role in this accomplishment. The Monitoring Panel and the Editorial Advisory Board recognize that the Editorial Staff has been instrumental in developing and maintaining the confidence of au- thors and of other editorial staffs. Since the Journal's initial publication in June 1967, the editors have at- tained a high level of competence in scientific editing. Their understanding of the pesticides field has been invaluable in evaluating each manuscript and deter- mining the extent of editing required. In spite of ex- tensive editing on many manuscripts, the record shows that Sylvia, Lynn, and Priscilla never offended a single author but, on the contrary, almost always received praise and gratitude for their efficient manner of editing. We are confident that our readers agree that the quality of the Journal exemplifies the efforts of the Editorial Staff in this area. Above all, the personal dedication of this fine staff will be missed. The Monitoring Panel and the Editorial Ad- visory Board commend them for a job well done and extend our best wishes. We would be remiss if we did not acknowledge that Paul Fuschini, the new Editorial Manager, and his staff fully recognize the importance of their new role. We wish to assure PMJ readers and contributing authors that the Editorial Advisory Board pledges its full sup- port to the new Editorial Staff in helping insure that the Journal will continue to merit the respect of the scientific community. John R. Wessel Chairman Editorial Advisory Board, PMJ Vol. 7, No. 3/4, March 1974 121 PESTICIDES IN PEOPLE Organochlorine Pesticide and Polychlorinated Biphenyl Residues in Biopsied Human Adipose Tissue — Texas 1969-72 James E. Bums' ABSTRACT Organochlorine pesticide residue levels were determined in 221 samples of human adipose tissue from elective surgery in 1969-72 in the lower Rio Grande Valley of Te.xas. Stand- ard electron capture — gas-liquid chromatographic inerhods were used. The total DDT level was 23.18 ppm: the DDE level was 17.37, the highest yet reported for a general population. Dieldrin and f} BHC levels were also high: 0.35 and 1.29 ppm, respectively. No decrease in storage levels during the study period was detected. There was no differ- ence due to se.x, but Mexican- Americans had significantly higher residues of DDE. p,p'-DDT. and dieldrin than did Anglo-Americans. Polychlorinated hiplienyls were detected in 15 samples in 1971 but none were detected in the other 3 years. Introduction The presence of organochlorine pesticide residues in humans and other nontarget organisms as a reflection of high lipid solubility and unusual stability has gen- erated much investigation. These studies have attempted to monitor temporal and geographic variations in resi- dues {1-14). The effort included epidemiological in- vestigations to define factors modifying residue levels and to detect alterations in morbidity and mortality (3. 7, 9, 15). This study reports organochlorine residues in adi- pose tissue of persons undergoing elective surgery in 1969-72 in the lower Rio Grande Valley of southeast Texas. The study area is a geographically isolated and well-defined semitropicai agricultural region. It has been subjected to heavy pesticides usage, predominantly on cotton. Incidental to the investigation of pesticide resi- dues has been the detection of polychlorinated biphenyls (PCB's). These compounds have been detected widely 1 U.S. Public Health Service, assigned to Technical Services Division. Office of Pesticide Programs, U.S. Environmental Protection Agency. 152 East Stenger, San Benito. Texas 78586. 122 in the environment and in human tissue (16, 17). This report also includes data on PCB's in the adipose samples analyzed for organochlorine residues. Methods and Materials A total of 302 samples of adipose tissue of approxi- mately 5 g each were obtained from elective surgeries performed at one local hospital in 1969-72. The samples were frozen within 30 minutes of excision and stored in glass containers with foil-lined lids at — 18°C until analysis. Demographic data were obtained by chart inspection; 81 samples were eliminated because of am- biguities, inconsistencies, insufficient lipid «30%), or nonlocal residence. It was not possible to determine a pesticide exposure history but none of the samples came from people with known unusual exposure. Extraction, cleanup, and analyses were performed in compliance with the methods prescribed for Community Pesticide Studies Laboratories (18). The extraction and cleanup procedures followed the modified Mills, Onley, and Gaither method {18. 19). The concentrated 6% and 15% diethyl ether in petroleum ether fractions were injected into a Micro-Tek 220 gas chromatograph using a tritium foil electron- capture detector and a 6-ft-by-'4-in. outer-diameter glass column. The column contained one of two combi- nations: 1.5% OV-17 and 1.95% QF-1 on 100-120 mesh Chromosorb W (HP), or 4% SE-30 and 6% OV-210 on 80-100 mesh Chromosorb W (HP). Operating con- ditions were: column, 200° C; inlet, 225° C; detector, 205° C; carrier gas, nitrogen; flow rate, 70 ml/min; parallel plate electron capture detector operated at DC voltage to cause Vz full-scale recorder deflection for 50 pg aldrin; attenuation, 10 by 16; operating voltage, 22 v; total theoretical plates, > 3500 for each column. Pesticides Monitoring Journal Quantitation was by peak height and all residues were calculated on a total extractable lipid basis. When there was any question of peak identity, thin-layer chroma- tography (TLC) confirmation was obtained. All 6% fractions were scanned by electron-capture — gas-liquid chromatography (EC-GLC) and TLC for PCB's and quantitated visually by TLC using Aroclor 1260 as the reference standard. precision of ± 50% when Aroclor 1260 is the reference standard (18). The limits of detectability for the residues reported are: 0.01 ppm for heptachlor epoxide, DDE, and dieldrin; 0.02 ppm for 13 BHC, o.p'DDT. TDE, and p.p'-DDJ; and 0.5 ppm for PCB's. Chemical names appear in the Appendix. Inter- and intralaboratory quality control samples and all standards were supplied by the Primate and Pesticides Effects Laboratory, Perrine, Florida. Quality control samples were stored and analyzed with each batch of study samples and the laboratory was in control for the entire study period. Recovery studies for all residues except PCB's were consistently above 80% and usually above 90% during the study period; residues are reported in this paper without adjustment. Recovery studies were not per- formed for PCB's but the method is known to have a Results Table 1 presents the mean level of the organochlorine residues found in adipose tissue of residents of the lower Rio Grande Valley of Texas for the study period 1969-72. Table 2 shows the percent occurrence of the same residues. In spite of the greatly decreased use of all these agents since 1968 and the abstinence, due to insect resistance, from DDT usage during the period, the level of these residues did not decrease. There are some apparently random, statistically significant variations but there are no trends. TABLE 1. — Mean orgGnochlorine pesticide residues in liiiman adipose tissue from elective surgery — Texas, 1969-72 Residue: ppm (mean ± standard deviation)' No. DDT-R "- DDE p,p'-DDT TDE o,p'-DDT Dieldrin HE 0BHC Total 221 23.18±15.36 17.37+10.90 3.48+2.54 .10+. 11 .24+.28 .35+.23 .11+. 11 1.23+.95 Year 1969 26 23.04±17.50 16.50+11.86 4.12+2.56 .14±.08 .34±.23 .33+.23 .14+.09 .93+.41 1970 68 21.03±11.15 I5.95±8.04 3.07±2.29 .09 +.12 .10+. 14 •■ .29±.22 ,08±.07 ' 1.21±.87 1971 88 22.32+15.79 16.58+11.26 3.44+2.53 .08±.09 .32+. 34 .36+.21 .14+. 10 = 1.34±1.21 1972 Sex Female 39 29.29±17.35 22.52+12.10' 3.08±2.75 .I4rt.l3 .25 + . 27 .43+.28 .14±.I3 1.20±.66 122 23.04±14.72 n.l2±10.33 3.62+2.71 .10+. 11 .24±.24 .35+.25 .ll+.U 1.20+1.10 Male 99 23.22+16.03 17.55±11.56 3.30+2.30 .llrt.ll .25+. 33 .34±.20 .Hi:. 10 1.26±.72 Ethnic 2 M.A. 151 25.75±16.16 19.35+11.73 3.84+2.58 .10+. 12 .24+.23 .38+.22 .12+. 11 1.23 + 1.04 Other 70 17.85 + 10.98 = 13.31+7.33 •"• 2.70±2.28 = .08±.08 .24+.38 .27+.18'-' .Il+.IO 1.17+.73 ' When p > .01, no notation appears; 4 values 2 DDT-R = DDT + 1.114 (DDE + TDE). ' M.A. — Mexican-American (.Spanish surname); other ' p <-.oi. = p < .001 (t-test). lOx the mean have been eliminated. All residues calculated on a total extractable lipid basis. Non-Spanish surname. TABLE 2. — Organochlorine pesticide residues in human adipose tissue from elective surgery — Texas. 1969-72 Percent Occurrence No. DDT-R 1 DDE p,p'-DDT TDE o,p'-DDT Dieldrin HE ^BHC Total 221 100 100 100 93 81 98 98 99 Year 1969 26 100 100 100 96 93 89 89 93 1970 68 100 100 99 90 56 99 97 100 1971 88 100 100 100 84 88 100 100 100 1972 39 100 100 100 100 97 100 100 100 .Sex Female 122 100 100 100 97 84 97 98 99 Male 99 100 100 100 88 77 100 98 100 Ethnic = M.A. 151 100 100 100 94 88 98 99 100 Other 70 100 100 100 91 64 99 96 99 ' DDT-R = total DDT + 1.114 (DDE + TDE). " M.A. = Spanish surname; other = Non-Spanish surname. Vol. 7, No. 3/4, March 1974 123 There are no sex differences in residue occurrence, but people with Spanish surnames have higher residues (total DDT, DDE, p,p'-DDT, and dieldrin) than people with non-Spanish surnames (p<0.001). Classification by Spanish surname is used as an approximation of Mexican heritage and is certainly only an approximation of ethnic origin. The mean sample storage intervals were 1.8 months in 1969, 6.7 months in 1970, 11.0 months in 1971, and 6.1 months in 1972. In spite of these rather marked dif- ferences there was no correlation between this variable and the residue levels. The mean ages for each year (56 for 1969, 55 for 1970, 54 for 1971, and 52 for 1972) suggest the samples were selected from the same population. There were also no differences in distribu- tion of ethnic group, sex, or type of surgery for any of the study years. The type of surgery from which our adipose samples were drawn is shown in Table 3. The proportion of lipid in the samples averaged 77.2%. There was no correlation between age and pesticide residues; almost all tissue samples were from adults. Previous reports have shown age correlations in only the youngest groups (i). TABLE 3. — Classification of elective surgery supplying adipose tissue — Texas, 1969-72 Inguinal hernia 44% Umbilical hernia 27% Incisional hernia 13% Hernia, other 4% Lipoma 6% Other types of surgery 6% 100% The detection of PCB's is detailed in Table 4; surprisingly, these residues appeared during one year only: 1971. This group of 15 people, compared to people not having PCB's, did not differ significantly in sex, ethnic back- ground, sample storage time, surgical procedure, or level of pesticide residues; but they were slightly older: 62.5 years vs. 51.5 years (p<0.01). Graphic analysis of the distribution of the seven residues showed them to be skewed somewhat to the right as has been demonstrated previously (19). The mean is used as the measure of central tendency for comparison to previous work rather than as the rigorous application of statistical principles. ! Discussion Although use of DDT and most other organochlorine pesticides in the Rio Grande Valley was discontinued one year before this study began, the storage level did not decrease among Rio Grande Valley residents. These pesticides have been replaced by organophosphates. These findings confirm the experience of Morgan and Roan (9) but contradict Warnich's findings in Utah (12). Duggan's food monitoring from 1965 to 1970 shows an apparent decrease in residue levels in food (20, 21). the major source of pesticide intake. This decrease, com- bined with a decrease in local use on cotton, should result in a detectable decrease in pesticide levels of human adipose, considering Morgan and Roan's (22) demonstration that storage levels are dependent upon continuing intake. The exact changes that may have oc- curred in pesticide intake via food for our study group are unknown, although it is evident from the data that no dramatic decrease has occurred. The significant (p<0.01) increase in DDE levels be- tween 1971 and 1972 is a perplexing find. There was no corresponding increase, during that year, in TDE or DDT levels as would be expected if there had been an increase in intake via food. In fact, the National Food Monitoring Program has shown that DDT levels are higher than DDE levels for almost all samples ex- amined (20. 21). TABLE 4. — Polychlorinated biphenyls in human adipose tissue from elective surgery — Te.xas, 1969-72 Polychlorinated Biphenyls (0 = >0.5 PPM) No. % POSI- Mean, Range. SAMPLES TIVE PPM PPM Total 221 7 0.1 0-9.9 Year 1969 26 0 0 0 1970 68 0 0 0 1971 88 15 1.7 0.6-9.9 1972 39 0 0 0 Sex (1971 only) Male 42 24 2.3 0.6-9.9 Female 46 11 0.9 0.6-1.0 Ethnic Background ' (1971 only) Mex.-Amer. 61 15 0.9 0.6-1.4 Anglo-Amer. 27 22 2.9 0.8-9.9 ^ By surname. 124 The conversion of DDT to DDE in vivo has been shown to proceed slowly (22) and the stability of DDT levels makes this conversion to DDE unlikely. A possible explanation for an increase in DDE levels alone could result from the discontinuation of DDT usage in the United States. This would cause an increase in the proportion of DDE, and a subsequent increase in the proportion of DDE found in human adipose. But this theory implies an increased exposure of humans to an environmental source of DDE, which seems un- likely. Further monitoring will be necessary to establish this hypothesis. The observed differences in DDE, p.p'-DDT, total DDT, and dieldrin between Mexican-Americans and Anglo- Pesticides Monitoring Journal Americans probably relate to socioeconomic factors ather than to any genetic diflferences. This conclusion s based on two studies. Davies (75) has attributed in- :reased DDT residues in blacks primarily to their lower ocioeconomic status rather than to their race: it has )een observed (23) that in the Rio Grande Valley a iisproportionate percentage of the lower socioeconomic ;roup are Mexican-American. from industrial areas but this has not been demon- strated; as stated earlier, it was not possible to determine a pesticide exposure history of persons in this study. Analysis of all variables identified in the study fails to demonstrate any significant diff'erences between the people with PCB residues and those without, except that the former are slightly older: 62.5 years vs. 51.5 years (p<0.001). Since it is unlikely that Mexican-Americans consume I larger amount of animal products, which have been ihown to contribute to the bulk of dietary pesticide in- ake (20. 21), the difi'erence in residues could relate to ;mployment, home use of pesticides, or other factors issociated with lower socioeconomic status. The lack of nformalion in this area discourages further speculation. \ comparison between the data of this report and the •esidue levels which have been reported previously re- zeals that these are the second-highest levels of total DDT (2) and the highest levels of DDE yet reported in 1 general population. The dieldrin and ft BHC levels ire also high but the heptachlor epoxide levels are not -emarkable {1-15, 21). National and international comparisons of specimens in 1 study of this type are subject to substantial hazards. 5ome specimens are from biopsies and others are from autopsies. Samples received are handled in various ways. ncluding storage in formaldehyde, freezing in plastic, 3r freezing in glass. There are significant differences in analytical technique: data are reported as means, medi- ans, and geometric means. Some data are reported on a Afet-weight basis and some on extractable-lipid basis. Some authors correct for recovery, and the computa- tion of total DDT sometimes fails to consider a differ- ;nce in molecular weight of DDE and TDE. At times, ;he work done in these areas is not even mentioned. However, many of the laboratories generating the data :ited above are operating under the same contract and quality control program as is this laboratory: compari- sons with such laboratories should be valid. The etiology of the high residues in our study group is probably intense pesticide usage necessitated by a com- bination of local agricultural needs and a climate favor- able to insects. Exactly how exposure occurs is obscure. Reporting residues on a total extractable lipid basis :ends to make our results uniformly about 20 to 25% greater than data determined on a tissue-weight basis but the variability of lipid in adipose samples (31 to 93% ) makes this a reasonable correction. The detection of PCB's in only one year is difficult to sxplain. Ttie study area is mostly rural with very little industrialization and consequently few sources of PCB's. It is possible that these residues represent immigrants Residue levels are in the range of those reported in the Tissue Monitoring Program (17) and in the Price-Welch study in Michigan (16) but the prevalence is certainly much lower. Without further data it must be assumed that the detection of PCB's in 1971, only, is a random event with no biological significance. See Appendix for chemical names used in this paper. Acknowledgments The study was initiated by J. S. Wiseman, Ph.D. Analytical work was done by E. D. Gomes. Contribu- tions of these and other members of the Texas Com- munity Pesticide Laboratory are greatly appreciated. This research was supported by the Technical Services Division, Office of Pesticides Programs, U.S. Environ- mental Protection Agency, through the Texas State Health Department Community Pesticide Study, con- tract number 68-02-0541. LITERATURE CITED (/) Dale. W. E.. and G. E. Quinby. 1963. Chlorinated in- secticides in body fat of people in the United States. Science 142: 593-595. (2) Dale. IV. E.. M. F. CopeUiml. ainl W. J. Hayes, Jr. 1965. Chlorinated insecticides in the body fat of people in India. Bull. W.H.O. 33: 471-477. (3) Denies. J. E.. IV. F. Edmundsoi]. ]. J. Schneider, and J. C. Cassady. 1968. Problems of prevalence of pesti- cide residues in humans. Pestic. Monit. J. 2(2): 80-85. (4) Edmundson, W. F., J. E. Davies, and W. Hill. 1968. Dieldrin storage levels in necropsy tissue from a south Florida population. Pestic. Monit. J. 2(2): 86-89. (5) Fiserova-Bergerova. V.. J. L. Radoniski, J. E. Davies, and J. H. Davis. 1967. Levels of chlorinated hydro- carbon pesticides in human tissues. Ind. Med. & Surg. 36(1): 65-70. (6) Hoffman, IV. S.. W . I. Fishhcin. and M. B. Andelman. 1964. The pesticide content of human fat tissue. Arch. Environ. Health 9: 387-394. (7) Hoffman, W. S., H. Alder, W. I. Fishbein. and F. C. Bayer. 1967. Relations of pesticide concentrations in fat to pathological changes in tissue. Arch. Environ. Health 15: 758-765. (8) Kadis. V. W., W. E. Breitkreitz. and O. J. Jonasson. 1970. Insecticide levels in human tissues of Alberta residents. Can. J. Pub. Health 61(5): 413-416. (9) Morgan, D. P.. and C. C. Roan. 1970. Chlorinated hy- drocarbon pesticide residue in human tissues. Arch. Environ. Health 20: 452-457. (10) Quinby, G. £., IV. J. Hayes, Jr., J. F. .Armstrong, and Vol. 7, No. 3/4, March 1974 125 W. F. Durlinm. 1965. DDT storage in the U.S. popula- tion. JAMA 191(3); 175-179. (11) Robinson, J. 1969. The burden of chlorinated hydro- carbon pesticides in man. Can. Med. Ass. J. 100; 180- 191. (12) Warnick, S. L. 1972. Organochlorine pesticide levels in human serum and adipose tissue, Utah — fiscal years 1967-1971. Pestic. Monit. J. 6(1); 9-13. (13) Wasscnnanu. M., D. Wasscniianii, L. ZcUcnmiycr. and M. Gon. 1967. Storage of DDT in the people of Israel. Pestic. Monit. J. 1(2): 15-20. (14) Wyllic. J.. J. Gabica. and W. W. Benson. 1972. Com- parative organochlorine pesticide residues in serum and biopsied lipoid tissue, a survey of 200 persons in south- ern Idaho— 1970. Pestic. Monit. J. 6(2); 84-88. (15) Davics. J. £., W. F. Edmiindson, A. Raffonclli, J. C. Cn.iSiuly, and C. Morgadc. 1972. The role of social class in human pesticide pollution. Amer. J. Fpidemiol. 96(5); 334-341. (16) Price. H. A., and R. L. Helcli. 1972. Occiuience of polychlorinated biphenyls in humans. Fnviron. Health Persp. 1; 73-78. (17) Yobs, A. R. 1972. Le\els of polychlorinated biphenyls in adipose tissue of the general population. Environ. Health Persp. 1; 79-81. (18) Thompson, J. F. (ed). 1972. Analysis of pesticide resi- dues in human and environmental samples. Primate and Pesticides Effects Laboratory, U. S. Environmental Protection Agency, Perrine, Fla. (19) Mills. P. A.. J. H. Onlcy, R. A. Gailher. 1963. Rapid method for chlorinated pesticide residues in non-fatty foods. J. Ass. Offic. Agr. Chem. 46; 186-191. {20) Diiggan, R. E., G. Q. Lipscond\ E. L. Co.x, R. E. Healwole, and R. C. Kling. 1971. Pesticide residue levels in foods in the United States from July 1, 1963 to June 30, 1969. Pestic. Monit. J. 5(2); 73-212. {21) Diiggan, R. E., and P. E. Corncliiis.u-n. 1972. Dietary intake of pesticide chemicals in the United States (111). June 1968-April 1970. Pestic. Monit. J. 5(4); 331-341. {22) Morgan, D. P.. and C. C. Roan. 1972. Loss of DDT from storage in hiuiian body fat. Nature 238; 221-223. {23) Office of the Governor, Office of Infornialion Services. 1972. Summary selected demographic characteristics from census data. Texas Health Data Institute. OIS- GR-3, 71-GR-OOl. Austin, Te.xas. 126 Pesticides Monitoring Journal RESIDUES IN FOOD AND FEED Surveys of Mercury Levels in Fish and Other Foods ' Robert E. Simpson," William Horwitz,- and Caesar A. Roy' ABSTRACT Tlic Food iiiid Diii.i; AdiniiiisliciUon (FDA) conduclcd u series of survey.s of llic mercury coiuent of food in 1970, 1971, and 1972. The surveys included a wide variety of fisli samples from selected freshwater regions, commercial fish from wliolesale distributors, and swordfish and canned tuna fish; 10 commodities representing a high proportion of total food consumption: and 12 total diet fractions collected in the FDA continuing market basket study to determine pesti- cide residues in the basic 2-week diet of a 19-year-old male. For most samples analyzed, atomic absorption was used as the determinative step; the more sensitive neutron activation technique was used to confirm low levels of mercury found by the atomic absorption method. Swordfish samples showed the highest incidence of mercury and the average mercury content, with levels in excess of 1 ppm in more than 50% of the samples examined. Approx- imately 4% of the canned tuna fish contained mercury in excess of the FDA guideline of 0.5 ppm for mercury in fish. Some freshwater species contained elevated levels of mercury traceable to known . Adniiiiislration districts witliin U.S. DHEW regions the same code were collected. All samples were for- warded as perishables under solid carbon dioxide by the collecting districts to one of the four analyzing districts" laboratories indicated by a star in Figure 1. The analyzing laboratoru;s prepared composites of each commodity collected at a given district; a portion of each composite was forv arded to the FDA headquarters laboratory in Washington, D.C., for mercury determi- nation by neutron activation analysis (NAA). In the FDA-NCA survey of canned tuna fish and sword- fish, samples were collected from warehouse stocks located in each district: samples consisted of 12 cans selected at random from different cases within a given lot. For the survey of wholesale fish (7), 19 different types of other commercial fish and shellfish were sampled. Each sample consisted of five 1-lb units, each unit from a different fish, making a total of 5 lb for each lot. For shellfish, the square root of the number of containers in the lot was sampled: a minimum of 5 and a maximum of 15 subdivisions were taken. Each subsample con- sisted of at least 1 lb. The shellfish sampling procedure was also used for packaged fish: fresh, frozen, or proc- essed. Each subsample contributed equally to a single thoroughly mixed slurry for analysis which was repre- sentative of the lot. The Total Diet program (.8) of FDA is a continuing market basket study in which 117 food items are col- lected and composited into 12 commodity groups for analysis. The program is intended to represent the 2- week diet of a 15- to 20-year-old male in each of the four regions of the country (Fig. 1) in which the samples are collected: Northeastern (I and II), Southern (III, IV, and VI). Central (V and VII), and Western (VIII, IX, X). The details of the selection, collection, prepara- tion, and compositing of the samples are described in 128 Pesticides Monitoring Journal references cV and 9. The homogenized, slurried com- posites of each commodity group were divided into 100-g portions and kept frozen imtil analyzed by the Kansas City District laboratory. In addition, portions of each commodity group were forwarded to the FDA headquarters laboratory in Washington for mercury analysis and multi-element screening by neutron activa- tion techniques. Analytical Methods Originally the dithizone method of the Association of Official Analytical Chemists ( AOAC) {10) and the cold vapor atomic absorption method of the Fisheries Re- search Board of Canada (.^) were used to analyze fish for mercury. When the results of the collaborative study conducted by Mimns and Holland (//) became available in late 1970. all subsequent analyses were made by their modification of the basic cold vapor atomic absorption method. The very low levels of mercury in foods other than fish necessitated the use of the more sensitive neutron activation method of evaluation. niTHIZONF METHOD The official final action AOAC method [10) consists of a nitric-siilfuric acid digestion imder reflux to avoid loss of mercury. The mercurx is isolated by dithizone extrac- tion, any interfering copper is removed, and the mer- cury dithizonate is determined spectrophotometrically. Extreme care is required to achieve complete digestion, or results will be low. The practical limit of detecta- bility is about 0.05 ppm. Recoveries by this method at levels of 0.2 ppm or greater ordinarily are above 90%-. ATOMIC ABSORPTION METHODS The original Canadian method of analysis involved sulfuric acid dissolution of the sample, cold perman- ganate oxidation, reduction and volatilization of the mercury, and reading in a vapor-flow cell. The current first action AOAC modification of this method (//) utilizes a nitric-sulfuric-perchloric acid digestion under reflux, reduction and volatilization, and reading in a vapor-flow cell. The practical limit of quantitative results with this method is about 0.02 ppm. Recoveries of mercury added to fish are about 80'~f at the 0.5 ppm level, with a coefficient of variation of about 15*7^ (//). The average and standard deviation obtained by 17 FDA laboratories for a ground, composited, refer- ence sample of canned tuna, oil packed, was 0.34 ± 0.05 ppm; the coefficient of variation was 15'^-, about the same as the collaborative study value (11), RADIOCHEMISTRY METHODS Older laboratories which at some time have utilized open containers of mercury, such as barometers and leveling bulbs, or any laboratory in which thermometers, calibrating equipment, or bottles of mercury have been Vol. 7. No. .3/4. March 1974 spilled or bioken may experience low levels of mercury contamination from hidden sources. The extreme sen- sitivity of neutron activation analysis therefore re- quired special preparation techniques. All samples were prepared in a mercury-free clean room Following irradiation, all sample vials were dcconlaminated of any possible extraneous radioactive mercury prior to radiochemical processing. The sulfide precipitation method adapted by Tanner (7 al. ( 12) from that developed by R. E. Jervis (4) was used to process all samples analyzed in the foods survey program. Sjostrand's electrolytic method (13) as modi- fied b\ Heitzman and Simpson (14) was also used to obtain comparative values with other methods on a limited number of selected samples. The mercury content of the samples was determined by assa\ing the -"-'Hg activity using the techniques of gamma ray scintillation spectrometry. Following a radiochemical separation, the sensitivity of neutron activation analysis for mercury is about 0.002 ppm for dry samples and about 0.001 ppm for freeze- dried samples calculated to the original wet-weight basis. All results were corrected by the individual recovery factor for the specific determination. The average re- covery factor was SS'^c . All results on freeze-dried samples were recalculated to the original wet-weight basis. Results and Discnssion COMPARISON OF METHODS A number of samples which had been analyzed by several other laboratories were available for compara- t'wc analyses. Although some results of this study have been reported elsewhere (12, 14), for the sake of com- pleteness the\' have been included in Table 1 with additional data. The concurrence of results between neutron activation analyses and atomic absorption methods, which measure total mercury, and the gas- liquid chromatographic (GLC) analyses, which mea- sure onl\' methyl mercury, indicates (a) that most of the mercury in the shrimp and two pike samples is present as methyl mercury, and (b) that mercury is not lost in freeze drying. The electrodeposition method yields mercury of high purity deposited on gold, and the results are in good agreement with those by the other methods. This tech- nique, however, is not practical for processing the large number of samples handled in these surveys. The results in Table 1 show remarkably good agree- ment by the various laboratories utilizing their individual 129 Iccliniqiics. In ;ill c;iscs, special care undoubtedly was taken to insure the reliability of the reported values. lis II SllKVHY A survey was initiated by the U.S. Department of the Interior — Federal Water Quality Administration (FWQA: a predecessor of the present U.S. Hnviron- mental Protection Agency — Air and Water Programs). J. R. Harlan, Conservation Consultant to FWQA, sent an inquiry to all State directors of fish, game, and conservation, soliciting information on the status of mercury pollution of natural resources under their jurisdictions ( 15). Results reported hy the States arc given in Table 2. Of the 4.S States who responded to the inquiry, 1.^ reported levels of mercury in fish in excess of O.."; ppm; at least six States reported levels higher then 4 ppm in some samples. Closures of fishing areas and/or warnings against eating fish from these polluted areas were issued by 16 of the States covered in the survey. In lake Hrie (Table ^) over 20% of the fish sampled by FDA in 1970 contained mercury in excess of the 0.5 ppm guideline; over .50'"; of the fish from Fake St. Clair in nearly Ontario Province, Canada, were above this level. Of these, 20% showed more than 1 ppm mercury. Fish from other regions, except for Fake Ontario, had residues well below this level. For com- parison, the mercury contents of fish from two Far Western areas are also listed in Table ?•. More than 60% of all samples analyzed contained less than 0.1 ppm mercury. The otlicial dithizone method of the AOAC (10) was used to analyze most samples collected in this survey. After adoption of the Munns and Holland method (//), about 60% of the Lake Erie samples were analyzed by atomic absorption. Results for the fish from Lake Erie and Lake St. Clair confirm the earlier Canad- ian findings: walleye, sheepshead, catfish, white bass, smallmouth bass, some perch, and carp contained the highest levels of mercury. Other data from the FDA survey of mercury contami- nation in fish are given in Table 4. Of 29 freshwater areas listed, only 13 had fish containing mercury in excess of the 0.5 ppm guideline; of these, only 9 areas had fish containing more than 1 ppm. Samples from all other areas contained less than 0.5 ppm mercury. The 1971-72 results for 13 different types of fish are shown in Figure 2. Of all the samples collected from various parts of the country, 40% (16 of 40 samples) contained levels of mercury in excess of 0.5 ppm. As illustrated in Figure 3, similar results were observed for imported freshwater fish. In this case about 45% (7 of 16 samples) contained more than 0.5 ppm. 130 PPM J <" P(U1 1 1.3 (NVU63 144 At Alciborxo t t GA-Gcorgm IL-lllmo.l I.I MD Morybnd Ml Michigan NV Nevada NV Naw Ya«4 UAl) .9 OH Oh.a BolNVI B Batt - B( Buffalo CMMII .7 Bu Bullhood CCa.p Cli-Chub C> Carf.if. WINVI CMINl CIGAlLIAl) - W(OHl I(MI| .5 ' 0 Drum l-ladyl.ih M MulUl IIMII BIAll WhIMI) "'°"' MINI BINVI BflGAI M(OH| .3 ' Sh Sk**pi»,*ad I Itoul Wh Whiting """ D|,N, PINYl """Ba(N») .1 Wh(ll) BIIACI B„|NV| PIMII ,|„^| CIOHI WhIMIl 0 . I.I. 1.1,1.1.1 . I.I. 1 3 5 7 9 11 1 3 5 7 71 71 72 MONTHS FKilJRH 2. — Mercury Iricl.'; in donieslic fre.shwuU'r fish, \'n()-72 PPM I.J 1.1 .9 .7 .5 .3 .1 0 PktN.lt 1.39 ^ IB*)- Belgium (Co) Conodo (C)i)-Chma (HK).Hong Kong (M.)-M..i.o Pk(Ne) (N«|-N«th.r(and( iM-rran'r'"""' ''■«^°i llhl-tha.lond 1 s„|Th) ClCa) |I.).I.A., ] Sn(HK| ' ' PMTr) C(Co| T|M«) PI((N«) D(Mxl . 1 . 1 . 1 . 1 . 1 . 1 . 1 CCp Cd-Cad D-D.um Pl-Pickaral Pk P«*pih«ad Sn SAoppcr - Sn(Nz Sh(Ch) PKSu) PMCa) Cd(Be) , I.I. 1 3 5 7 9 11 1 71 71 72 MONTHS 3 5 7 FIGURE 3. — Mercury in imparled fre.sliwuler fish, 1970-72 FIGURE 4. — Mercury in fish collected from Pickwick Reservoir, Tennessee Valley Authority Pesticides Monitoring Journal 2 0 - 1 1 1 i 1 ' 1 t 1 1 1 T 1 1 5 - X I 10 a. H \ 1 0 5 0 K- 1'' ■^. , I M - MJJASONDJ FMAMJJASONDJ FMAMJJASONO FIGUKH 5. — Mcrciiiy in fish collcclcil from Kcnliicky Risii\(>ir. Tennessee Valley Aiahorily NUMBER OF SAMPLES 90r 0 J^^^js^^x-s^sx-a^^-^s^^^ .00 .10 .20 .30 .40 .50 .60 .70 PPM FIGURE 6. — Dislribiiiion of meieury in tilbcworc {NCA data) Since 1967 the Bureau of Sport Fisheries and WildHfe, U.S. Department of the Interior, has conducted a monitoring program for pesticides in fish collected from various lakes and streams throughout the United States. Results from an extensive survey for mercury in fresh- water fish, recently reported by Henderson, Inglis, and Johnson (16), indicated that in 1969 values ranged from <0.05 to 1.25 ppm and in 1970 from <0.05 to 1.80 ppm total mercury in the edible portions. Of 100 Vol. 7, No. 3/4, March 1974 monitoring stations, average values for total mercury exceeded the FDA guideline of 0.5 ppm at three stations in 1969 and at six stations in 1970. Along with other collaborating organizations monitoring mercury pollution in freshwater areas of the United States, the Water Quality Control Branch (WQCB) of the Tennessee Valley Authority (TVA) has been co- operating with the Food and Drug Administration and the U.S. Environmental Protection Agency (EPA). In a recent report covering their survey of mercury in fish from TVA reservoirs (/7). WQCB found significantly high levels of mercury in fish obtained from both the Pickwick, Tennessee, and the Kentucky reservoirs (Fig. 4, 5). After eliminating the discharge of mercury into these waters, TVA researchers have observed a down- ward trend in mercury concentrations among reservoir fish, though the level remains above 0.5 ppm. As over- laying mercury-free sediments continue to collect in these waters, researchers expect this downward trend to continue. CANNED TUNA FISH Analyses of over 3,000 samples of canned tuna (Table 5) show an average overall mercury content of about 0.25 ppm, with less than 4% over the 0.5 ppm guideline. The coefficient of correlation between weight of fish and mercury level is given for each type of fish and for all types combined for the National Canners Association (NCA) data. Weights were not available for the im- ported samples, and such correlations could not be ex- amined. This correlation is highly significant in domestic samples for albacore (p<0.001), yellow fin (p<0.001), the "other" category (p<0.0l). and all types combined (p<0.0001), indicating that the mercury concentration increases with an increase in fish size. The correlation for skipjack was not significant, perhaps because the largest weight for the skipjack was 25 lb, and the in- creased opportunity of the larger fish to concentrate the mercury may be more manifest in fish larger than 25 lb. Figures 6 and 7 show that the mercury concentration in albacore and skipjack tuna approaches a normal distribution; the larger albacore has the greater number of samples with elevated levels of mercury. Only in im- ported tuna (Fig. 8) is the distribution skewed above 0.5 ppm. More recent results illustrated in Figure 9, how- ever, suggest a downward trend for both domestic packs and imported tuna. This probably indicates closer scrutiny by the suppliers, rather than any real reduction of mercury concentration in these fish species. HALIBUT During the 1971-72 mercury survey, FDA analyzed more than 500 samples of domestic and imported halibut (Table 6.) The overall average concentration of mercury was about 0.25 ppm, and about 13% of the samples were above the 0.5 ppm guideline. 131 SWORDFISH Results for swordfish are quite diflferent from those for halibut. Of 853 samples analyzed in 1971 (Table 7), over 95% exceeded the 0.5 ppm guideline and over 50% of the samples exceeded 1 ppm mercury. As Figure 10 shows, however, the concentration approaches a normal distribution, as in tuna, with the greatest number in the range 0.75-0.99 ppm. As a result of these findings, FDA recommended that the public not eat swordfish and that this commodity be recalled from the domestic market (/). Commercial swordfish usually average about 150 lb each; hence these findings are not surprising in view of the correlations with weight in tuna, as mentioned earlier. COMMERCIAL FISH AND SEAFOOD Among the more than 1,300 samples of 19 different types of other commercial fish and seafood collected in 1971, only six types included one or more fish with a mercury content above the 0,5 ppm guideline (Table 8). Of those species containing a significant number of samples, bonita and snapper averaged more than 0.2 ppm mercury. Although a few crab, cod, flounder, lobster, and herring reached this level, the high-level samples constituted less than 10% within each type. SURVEY OF MERCURY IN FOOD (5) Of all food examined for mercury content, measurable quantities were found only in shrimp when examined by the neutron activation technique (12); it had a high value of 0.043 ppm and a median value of 0.014 ppm (Table 9). Nonfat dry milk was next highest with a high of 0.027 ppm and a median of 0.010 ppm. The mercury level in nonfat dry milk, when reconstituted, is of the same order as that in fluid whole milk: ap- proximately 0.002 ppm. All commodities except shrimp were also analyzed by the dithizone and the atomic absorption methods, which were not sensitive enough to measure with absolute precision such low levels of mercury. Table 9 gives the median and range of values in the 10 commodities found by the neutron activation method only. TOTAL DIET SURVEYS Results from the most recent total diet survey by the current neutron activation analysis method (12) are presented in Table 10 with results reported previously (2). All commodities except meat, fish, and poultry (Group II) contained less than 0.014 ppm mercury. The meat, fish, and poultry group contained mercury ranging from 0.004 to 0.041 ppm, depending upon the mercury level in the fish component. The amount of mercury currently found in red meat muscle tissue is about O.OIO ppm (1972, A. J. Spaulding, United States Department of Agriculture, persona! communication.). comparable to the levels generally found in Fraction II. 132 NUMBER OF SAMPLES 50r .00 .10 .20 .30 .40 PPM .50 .60 .70 FIGURE 7. — Dislribuiion of mercury in .iliipjack tuna INCA) NUMBER OF SAMPLES 40 .00 .10 .20 .30 .40 .50 .60 .70 .80 .90 PPM FIGURE 8. — Distribution of mercury in imported tuna Pesticides Monitoring Journal o PPM A 272 A A 396 ^"l.40 "74 0 4.92 1.3 1.1 t t t t t a Angola ft Colifomlc OJopor .9 .7 - ft A D A Pwflrto (tko - .5 .3 .1 - 0 D A o Po ° o^o a 0 o ° o o _ D ft '^ D A 0 0 1 1 1 1 , 1 . 1 . 1 . 1,1,1. 1 1 3 5 7 9 11 13 5 7 70 71 71 MONTHS 72 FIGURE 9. — Mcixiiry in both domestic aiul iiuporwd tuna com hi tied PERCENT OF SAMPLES 40i 30 20 10 1 t <.5.5 .7 .9 1.1 1.3 1.5 1.7 1.9 2.0 PPM FIGURE 10. — Dislribulion of mercury in swordfish The earlier results are higher than current data by one order of magnitude (2). This was probably due to the presence of low-level mercury contamination introduced in earlier sample preparation, the significance of which has been recognized only recently (12). This same factor also may have been responsible for the high results reported earlier in the Jervis study (4). Conclusion Of all commodities analyzed for mercury in the surveys reported in this paper, fish appears to present the only potential hazard to man. However, levels of mercury that exceed the 0.5 ppm guideline for fish are found only in the larger species (large tuna, halibut, and sword- fish) of the commercially important varieties and in fish obtained from waters of known mercury pollution. In all other commodities, mercury either is not de- tectable or is present at levels approximating two orders of magnitude lower than the guideline for fish. A cknowledgments 1 . Data from the fish and foods survey were collated by the Oflnce of Compliance, U.S. DHEW-FDA, with special cooperation of Mary J. Dolan. The FDA District inspectors and laboratory personnel (Fig. 1) who col- lected and analyzed the samples were responsible for the success of these surveys. 2. James Winbush, Janet Springer, and other members of the mathematical staff have assisted greatly in sta- tistically evaluating data. Fish data were processed by Daryl C. Fleming of the Systems Analysis Branch, Oflfice of Executive Director of Regional Operations. 3. The neutron activation analysis results of the foods survey were acquired through the efforts of James T. Tanner and colleagues {12) in the FDA facilities at the National Bureau of Standards reactor in Gaithersburg, Maryland. These facilities are made available to FDA through an interagency agreement among several agencies: DHEW-FDA and Department of Com- merce NBS. 4. We appreciate the cooperation of other organizations mentioned in the text, who permitted their data to com- plete results of the study. LITERATURE CITED (/) Nelson. N.. T. C. Byerly, A. C. Kolbye, et at. 1971. Hazards of mercury. Environ. Res., Ch. 4, pp. 1-69. (2) Cornelitissen. P. E. 1969. Pesticide residues in total diet samples (IV). Pestic. Monit. J. 2(4): 140-152. (3) Mercury Contamination in Fish, FDA Compliance Program FH-19. 1970. (4) Jervis. R. £., D. Dehriin. W. LePagc. and B. Tiefen- hacli. 1970. Mercury residues in Canadian foods, fish, wildlife. University of Toronto, Summary of Progress, National Health Grant Project No. 605-7-510. (5) Mercury in Foods Survev. FDA Compliance Program FH-19. 1970. (6) U.S. FDA Fad Sheet. Dec. 15. 1970. Mercury residues in canned tuna. U.S. DHEW/PHS. (7) Mercury-Wholesale Fish Suivcv. FDA Compliance Program FH-19. 1971. (8) Chemical Contamination, Pesticide Residues: Total Diet Studies. U.S. FDA Compliance Program FH-IO. 1970. (9) Duggan. R. £., and F. J. McFarland. 1967. Residues in food and feed. Pestic. Monit. J. 1(1); 1-5. Vol. 7, No. 3/4, March 1974 133 (10) Horwitz, William (ed.). 1970. Official methods of an- alysis of the Association of Official Analytical Chemists. 1 1th ed. Assoc. Off. Anal. Chem., Washington, D.C., 25.058-25.065. (//) Miiiuis, R. K. and D. C. Holland. 1971. Determination of mercury in fish by fiameless atomic absorption: a collaborative study. J. Assoc. Off. Anal. Chem. 54(1): 202-205. (12) Tanner, J. T.. M. H. Friedman, et al. 1972. Determina- tion of mercury in common foods by neutron activation analysis. Science 177: 1102-1103. (/.?) Sjostrand. B. 1964. Simultaneous determination of mer- cury and arsenic in biological and organic materials by activation analysis. Anal. Chem. .36: 814-819. (14) Heitzman, M. W., and R. E. Simpson. 1972. Neutron activation analysis for mercury in fish, flour, and stand- ard reference orchard leaves by electrodeposition radiochemistry. J. Assoc. Ofi'. Anal. Chem. 55: 960-965. (15) Harlan. J. R. 1971. Mercury pollution survey. Sport Fishing Inst. Bull. No. 221: 4-7. (16) Henderson, C, A. Inglis, and W. L. Jolinson. 1972. Mercury residues in fish, 1969-1970 — National Pesti- cide Monitoring Program. Pestic. Monit. J. 6(3): 144- 159. (/7) CInirchill, M. A. June 1972. Mercury concentration in fish flesh — survey of TVA reservoirs. TVA Report, Summary of Data, May 1970-May 1972. TABLE 1. — Comparative results Ippm) of mercury lesls, using different analytical methods Radiochemtstrv of Neutron Activated Samples FOR Total Mercury i Other Methods Commodity Sulfide Precipitation Electholytic Deposition Pyrolysis - Gas Chromatography (Methyl Mercury) Atomic Absorption (Total Mercury) FDA shrimp 0.033 ± 0.003 0.029 ± 0.003 0.026 ± 0.003 0.043 ± 0.004 '0.03 0.03 0.04 0.06 *0.03 0.02 0.00 0.01 Swedish pike '■ F-410-28 2.16 ± 0.22 2.24 ± 0.22 " 1.94 2.20 ± 0.15 '«2.19 ± 0.10 »" 2.22 ± 0.03 " 1.88 Swedish pike F-4 10-30 1.29 ± 0.13 1.17 ± O.Il " 1.10 1.18 ± 0.15 '^ 1.18 ± 0.02 -iM.lO ± 0.03 » 1.10 Orchard leaves ^ 0.148 ± 0.01 0.162 ± 0.02 0.154 ± 0.02 0.169 ± 0.02 0.155 ± 0.015 CHPB flours 0.011 ± O.OI » 0.014 ± 0.004 0.012 ± 0.002 0.015 ± 0.002 0.008 ± 0.002 O.OU ± 0.003 "0.013 FDA flour " 0.002 ± 0.002 " 0.004 IAEA flour >= 4.6 ± 0.5 4.9 ± 0.3 4.87 ± 0.5 Bowman kale " 0.25 ± 0.03 ^•■' 0.23 AH FDA neutron activation analysis data represent single determi- nations; therefore, ± deviations represent counting error and radio- chemical uncertainties arbitrarily set at ± 10% ■ Rook, H. L.. T. E. Gills, and P. D. Laflenr. 1972. Anal. Chem. 44: 1114. L. R. Kamps. 1971. FDA Headquarters. Private communication, (a) Samples analyzed on a wet basis, average of 3 replicates; (b) samples analyzed after freeze drying, average of duplicates. FD.4 District results. 1971. Office of Compliance Report. Pike samples courtesy of National Institute of Public Health. Stock- holm, Sweden. " IVestoo. G. 1971 . Stockholm. Sweden. Private communication. ■ NBS Standard Reference itI571. 1971. "Orchard Leaves." "■ Flour sample C-32572 courtesy of H. M. Cunningham. 1971. Ca- nadian Health Protection Branch. " Somers. E. 1971. Proceedings Mercury Conference, Ottawa, Canada. '" FDA flour survey sample. 1971. " Lyon, W. 1971. Oak Ridge National Laboratory. Private communi- cation, '- IAEA Standard Flour 66/10. 1969. 1' Nadkarni. R. A., and W. D. Ehmann. 1969. J. Radioanal. Chem. 3:175-185. TABLE 2. — Mercury in freshwater fish^ State Arhas Findings Actions Alabama Pickwick Reservoir, tributaries of Tennessee River, Tombigbee River Trace to 0.5 ppm Closed to commercial fishing Arizona No findings reported California Sacramento-San Joaquin Delta Clear Lake Up to 1.27 ppm No closures Colorado Eastern irrigation reservoir [1,04 to 0.08 ppm No closures Connecticut No findings reported Delaware Delaware River. Delaware Bay <0.5 ppm No closures Florida Pulp mill areas No Hg found = — Georgia Fresh and estuary waters Not reported Savannah River and Brunswick Estuary closed Hawaii No findings reported Idaho No findings reported 134 Pesticides Monitoring Journal TABLE 2. — Mercury in fresliwaler fish^ — Continued State Areas Findings Action s Illinois Mississippi River, St. Clair Co. Three samplings each: carp, 0.09-15 ppm catfish, 0.44 ppm white bass, 0.20 ppm perch. 0.15 ppm shad, 0.08 ppm No closures Indiana Waters of Lake Michigan Whole fish, 0.18 ppm = No closures Iowa Random sampling 0-0.002 ppm = No closures Kansas Kaw Rivers Hg found = No closures Kentucky Tennessee River below Kentucky Dam 0.6 to 1.14 ppm Stopped commercial fishing in Tennessee River area of Kentucky Louisiana Calcasieu Lake Not reported Warning against eating lake fish Massachusetts Launton River area Fish, 0.17-1.21 ppm; shellfish, mussels, clam, 0.3-4 ppm No closures Michigan St. Clair River Wyandotte, Detroit River 0-7 ppm " Commercial closure of St. Clair River, Lake St. Clair, Lake Erie Minnesota Statewide <0.5 ppm except Red River of the North No closures Mississippi Missouri Montana Unspecified No known Hg pollution sources ' Above and below pulp mill 0.05-1.14 ppm (in Alabama) Trace ^ No closures No closures Nebraska No findings reported Nevada No findings reported New Hampshire Connecticut River Merrimack River Of fish analyzed, Vi >0.5 ppm; ■4 >0.5 ppm; highest, 1.3 ppm No closures New Jersey Arthur Kill River 0.03-0.21 ppm No closures New Mexico Navajo Lake Avalon Reservoir Elephant Butte Reservoir Animas River All varieties, 0-0.16 ppm; brown trout, 1. 14-1. 16 ppm; bullheads, 0.68 ppm; catfish & trout, 0.34 ppm; bluegills, 0.4 ppm 0.05-0.22 ppm 0.14-0.7 ppm Catfish & trout, 0.13 ppm Warning against eating fish New York Statewide Range 0.01-8.2 ppm Warning against eating fish; Lake Ontario; Lake Champlain; Lake Erie; St. Lawrence, Oswego & Niagara Rivers North Carolina Cape Fear River Hg contamination found ' No closures but monitoring of inland areas initiated Ohio Kiser Lake Buckeye Lake Maumee River Walleye, 0.55 ppm White bass, 0.59 ppm Lake Erie Range 0.04-1.51 ppm Lake Erie closed to commercial fishing; warning to others Western Basin Coho, 0.24 ppm; walleye, 0.62-1.4; white bass, 0.8 ppm; perch, 0.48-0.78 ppm; carp, 0.67 ppm; mullet, 0.47 ppm; drum, 0.29-0.65 ppm; catfish. 0.07-4.6 ppm Vermilion area Perch, 0.22 ppm; carp, 0.22 ppm Cleveland area Perch. 0.55 ppm; mullet, 0.5 ppm Oklahoma No findings reported Oregon Pennsylvania Unspecified Lake Erie only Hg source No Hg found 0.5-3 ppm Warning against Lake Erie fish Rhode Island South Carolina Unspecified No fi No Hg found ndings reported Savannah River closed Augusta to Coast South Dakota Oake Reservoir, Cheyenne River Impoundment to Missouri River 0,03-0.35 ppm No closures Tennessee Pickwick Lake No data cited Closed to commercial fishing Texas Houston Ship Channel Lavaca Bay Waters, 19 ppm (?) oysters >5 ppm Lavaca Bay closed Utah Limited survey 0.03-0.06 ppm No closures Vermont Lake Champlain Other lakes and ponds '/5 of fish samples >0.5 ppm '/g >0.5 ppm Closed to commercial fishing Virginia No fi ndings reported Warning against fish from N. Fork Holston River Washington Unspecified Unspecified No waters closed in any areas West Virginia Ohio and Monongahela Rivers No data Closure of these reservoirs Wisconsin Wisconsin River of known Hg use High as 4.62 ppm Restraint warning Wyoming Ocean Lake Reservoir; Alcova Reservoir 0.05-0.116 ppm No closures ' Survey initiated by USDl— Federal Water Quality Administration (FWQA). 1970. = Reported by R. H. Stroud. 1971. Marine Sport Fisheries Research. Sport Fishing Inst. Bull. No. 221 (15). Vol. 7, No. 3/4, March 1974 135 TABLE ^.—Mercury in Great Lakes fish, 1970 Type No. OF Samples Mean ± standard deviation (PPM) Percent in ppm ranges of: Region <0.1 0.1-0.50 0.51-1 >1 >2 Lake Erie Walleye 26 0.58 ± 0.26 4 27 61 8 2 Perch 53 0.24 ± 0.14 8 85 7 0 — White bass 37 0.49 ± 0.31 6 38 48 8 0 Shecpshcad 29 0.28 ± 0.21 15 65 20 0 — Carp 19 0.28 ± 0.29 17 75 4 4 0 Mullet 11 0.21 ± 0.16 27 73 0 0 — Sucker 14 0.21 ± 0.13 21 79 0 0 — Catfish 20 0.23 ± 0.20 30 55 15 0 — Smallmouth bass 13 0.51 ± 0.19 0 69 31 0 — All others 55 0.19 ± 0.23 44 49 7 0 — Lake St. Clair Perch 18 0.88 ± 0.75 0 40 30 30 2 (Ontario Prov- ince, Canada) All others 32 0.48 ± 0.32 3 56 34 7 0 Lake Michigan All types 40 0.11 ± 0.11 62 38 0 0 — Lake Ontario All types 74 0.30 ± 0.30 12 74 10 4 0 Lake Huron All types 23 0.19 ± 0.11 22 78 0 0 — Lake Superior All types 10 0.13 ± 0.11 20 80 0 0 — Columbia River ^ All types 27 0.05 ± 0.07 63 37 0 0 — Puget Sound i All types 11 0.03 ± 0.07 82 18 0 0 — These samples were collected from assumed uncontaminaled Western areas for comparison with Great Lakes fish. TABLE 4. — Mercury in fish jrom various freshwater areas, 1970 Type of Fish Number OF Samples ' Mean :t STANDARD DEVIATION (PPM) Percent IN PPM ranges of: Region <0.1 0.1-0.50 0.51-1 >1 >2 Savannah River, Augusta, Ga. All types 12 0.56 ± 0.26 11 32 57 0 — Beaverhead River, Mont. All types 10 0.57 ± 0.34 0 60 30 10 0 Belle Pourche, R.L All types 12 0.22 ± 0.22 42 50 8 0 — Calcasieu Lake, La. All types 16 0.39 ± 0.41 31 31 31 7 0 Cape Fear River, N.C. Catfish 9 1.14 ± 0.59 0 12 33 55 0 Cherokee, Tenn., and Boone, Ky., All types 13 0.15 ± 0.14 46 54 0 0 — Reservoir Chocooloco Creek All types 8 0.39 ± 0.16 0 75 25 0 Lake Charles, La. All types 23 0.31 ± 0.35 ti 65 9 4 0 Mississippi River All types 54 0.22 =t 0.28 37 48 9 6 0 Muscle Shoals, Ala. All types 6 0.97 ± 0.75 0 34 33 33 1 Niagara River All types 8 0.15 ± 0.07 1 99 0 0 — Oake Reservoir, Dakotas All types 12 0.29 ± 0.24 0 84 16 0 - Riegelwood, N.C. Catfish 14 0.84 i: 0.27 0 8 71 21 0 Others '2 1.03 ± 0.56 0 8 42 50 0 Red River, Texas All types 10 0.17 ± 0.09 20 80 0 0 — Sheffield, Ala. All types 8 1.00 ± 0.89 0 38 12 50 2 St. Lawrence River All types 9 1.16 ± 0.50 0 12 44 44 1 Tennessee River All types 11 0.20 ± 0.12 18 82 0 0 - Wheeler Lake, Ala. All types 7 0.29 ± 0.09 0 100 0 0 — Whitlock Bay All types 7 0.13 ± 0.05 27 73 0 0 — Yellowstone and Tonque Reservoirs, Mont. All types 10 0.16 ± 0.08 40 60 n 0 — Nine other areas - All types 29 0.06 ± 0.03 86 18 0 0 — ^ The atomic absorption method was River. ^ Each body of water had 3-5 samples. 136 used to analyze samples from all hut three sources: Calcasieu Lake, Lake Charles, and the Mississippi Pesticides Monitoring Journal TABLE 5. — Mercury in tuna fish Skipjack Yellowfin IMPORTED SAMPLES PROCESSED BY FDA Number in sample 936 1437 135 200 Mean mercury level (rrm) 0.20 0.31 0.17 0.31 Standard deviation 0.085 0.11 0.097 0.18 Upper 99^0 confidence limit on mean 0.21 0.314 0.19 0.34 Upper 99'« tolerance limit on 99% ot population 041 0.59 0,44 0.80 Upper 99% tolerance limit on 95% of population 0.35 0.51 0.36 0.67 DOMESTIC SAMPLES PROCESSED BY NATIONAL CANNERS ASSOCIATION Number in sample 149 383 288 70 Mean mercury level (ppm) 0.16 0.25 0.21 0.20 Standard deviation 0,078 O.IO 0.12 0.12 Upper 999b confidence limit on mean 0.17 0.26 0.23 0.24 Upper 99% tolerance limit on 99% of population 0.37 0.52 0.51 0.55 Upper 99% tolerance limit on 95% of population 0.31 0,44 0,42 0.46 Mean weight * 8.18 31.17 50.60 24.86 Correlation coefficient ^ 0.041 = 0.33 -• 0.33 ••0.44, = 0.67 Based on fewer samples than given above. Significant at P<0.001. Significant at P<0.0\. TABLE 6. — Mercury concentration in Imiibut^ Collection Mercury, ppm No. OF Percent of State and County, No. OF Samples OR Country Month & Year Samples High Low Average ± a >0.5 PPM >0.5 PPM Alaska, Prince of Wales Co. 8, 10, & 11 71 60 0.92 0.12 0.39 0.19 13 20 California, Alameda Co. 2 71 3 0.16 0.04 0.10 Los Angeles Co. 2&9 71 6 0.37 0.07 0.20 Illinois, Cook Co. 2&3 71 8 0,71 0.05 0.19 0.25 1 Massachusetts, Suffolk Co. 2 71 4 1,40 0.08 0.41 1 Oregon, Clatsop Co. 9 71 13 0.41 0.18 0.28 0.08 Pennsylvania, Phila. 2 71 17 0.29 0.03 0.14 0.07 Washington, King Co. 7 71 9 0.31 0.07 0.13 0.08 8 71 78 0,76 0.08 0.29 0.13 3 4 9 71 65 1,52 0.13 0.45 0.27 20 30 10 71 64 1.50 0.07 0.40 0.34 17 27 11 71 5 0.28 0.07 0.21 0.09 5 72 5 0.73 0.60 0.70 0.06 5 100 Washington, Snohomish Co. 10 71 12 0.49 0.11 0.18 0.10 11 71 6 0.29 0.18 0.24 0.05 Washington, Whatcom Co.-' 8 71 23 0.12 0.06 0.12 0.06 10 71 27 0.59 0.07 0.23 0.13 3 11 Canada ^ 7 71 5 0.39 0.05 0.24 0.15 8 71 6 0.13 0.05 0.11 0,06 9 71 17 0.46 0.06 0.16 0.10 10 71 22 0.26 0.02 0.17 0.07 11 71 15 0.74 0.10 0,29 0.21 3 23 12 71 12 1.10 0.04 0.30 0.28 2 17 1 72 11 0.49 0.16 0.37 0.11 2 72 11 0.49 0.10 0.22 0.14 3 72 3 0.30 0.17 0.22 0.07 5 72 6 0.49 0.18 0.28 0.14 6 72 4 0.25 0.03 0.15 0.09 Japan 10 71 3 0,31 0.08 0.22 0.12 11 71 3 0.42 0.24 0.30 0.1 3 72 6 0.32 0.03 0.21 0.09 5 72 7 0.25 0.12 0.16 0.05 6 72 4 0.12 0.10 ^ Overall total = 543 samples with an overall mercury concentration = 0.25 ppm with 68 (13%) in excess of 0.5 ppm. = Total sample for Washington State = 294; total >0.5 ppm = 48 (16%). » Total Canadian sample = 122; total >0.5 ppm = 5 (4%). TABLE 7. — Distribution of mercury levels in swordfish above 0.5-ppm guideline^ Range of Percent of samples Mercury Levels, ppm AT THIS level <0.50 >0.50-0.74 13.7 0.75-0.99 33.2 1.00-1.24 26.5 1.25-1.49 15.3 1.50-1.99 8.5 2.00-2.99 2.4 3. 00- > 3. 00 0.3 99.9 ' Of all swordfish sampled, 95% exceeded 0.5 ppm mercury. Vol. 7, No. 3/4, March 1974 137 TABLE 8. — Mercury in wholesale fish Mean Std. Dev. Upper 99% Upper 95% Upper 99% Mercury Total No. Std. Dev. Between Lots Confidence Tolerance Tolerance Level, Sub- OF Within (Component Limit on Limit on Limit on Fish Type PPM samples Lots Lots OF Variance) Mean 99% OF Lots 99% OF Lots Bonita 0.30 41 34 0.04 0.19 0.38 0.87 0.94 Clams 0.03 158 81 0.03 0.03 0.04 0.13 0.13 Cod 0.09 170 80 0.04 0.07 0.11 0.31 0.32 Crab 0.11 236 85 0.09 0.09 0.14 0.39 0.41 Flounder 0.08 156 76 0.03 0.05 0.09 0.23 0.24 Halibut 0.14 151 82 0.03 0.07 0.16 0.38 0.40 Haddock 0.04 179 77 0.01 0.03 0.05 0.13 0.13 Herring 0.07 107 77 0.01 0.05 0.08 0.20 0.21 Lobster 0.07 185 83 0.02 0.06 0.09 0.23 0.24 Mackerel 0.12 140 91 0.11 0.20 0.17 0.70 0.74 Oysters 0.03 203 86 0.02 0.04 0.04 0.15 0.18 Perch 0.06 209 83 0.02 0.06 0.07 0.22 0.23 Salmon 0.04 99 78 0.03 0.02 0.05 0.13 0.14 Sardines 0.02 104 76 0.01 0.02 0.03 0.08 0.08 Scallops 0.02 171 76 0.01 0.02 0.03 0.07 0.08 Snapper 0.31 186 86 0.10 0.15 0.35 0.75 0.78 Trout 0.09 151 83 0.03 0.10 0.12 0.37 0.39 Whitefish 0.05 65 48 0.03 0.03 0.07 0.18 0.19 Whiting 0.06 133 61 0.06 0.04 0.08 0.22 0.23 TABLE 9. — Neulron aclivalion analysis for mercury in foods (12) Mercury Residues in ppm = No. OF Samples Commodity Median Range (1) Flour 28 <0.003 <0.003-O.0O6 (2) Nonfat dry milk 3 0.010 20 0.044 0.050 0.033 0.127 0.08 — Shad >10 0.669 0.030 0.045 0.744 0.09 — SAMPLING AREA 3— TAMPA BAY, FLA. Crabs Weak fish Mullet 10 5 5 0.027 0.075 0.071 0.004 0.033 0.051 0.014 0.082 0.045 0.045 0.190 0.167 0.03 0.83 0.31 SAMPLING AREA 4— JACKSONVILLE, FLA. Blue crabs 15 0.011 0.011 0.035 0.057 0.08 — Shrimp 1 kg 0.006 0.014 0.029 0.049 0.60 — Flounder 3 0.162 0.128 0.524 0.814 0.65 — Weak fish 5 0.067 0.019 0.127 0.213 0.44 — Gray snapper 2 0.007 — — 0.007 — — Grouper 3 0.041 — — 0.041 — — Drum 5 0.013 0.011 0.041 0.065 0.17 — Croaker 5 0.015 — — 0.015 — — SAMPLING AREA 5— SAVANNAH, GA. Blue crabs 16 0.023 _ _ 0.023 — 0.014 Shrimp 0.5 kg 0.005 — — 0.005 — 0.007 Pilot shrimp 0.5 kg 0.016 — 0.01 1 0.027 — 0.007 Oysters 15 0.009 — — 0.009 — — Razorback clams 28 0.020 0,016 0.020 0.056 — — Squid 5 — — ^ — — 0.007 Flounder 4 0.014 — 0.004 0.018 — 0.005 Weak fish 1 0.020 0.006 0.014 0.040 — 0.024 Mullet 1 0.004 — 0.003 0.007 — 0.006 Shad 13 0.027 0.023 0.028 0.078 — 0.009 Other fish 5 0.041 0.032 0.034 0.107 — 0.014 SAMPLING AREA CHARLESTON, S. C. Blue crabs 10 0.057 0.057 _ _ Shrimp 1 kg 0.015 — — 0.015 0.02 — Oysters >15 0.017 — — 0.017 — — Squid >15 — — — — — — Croaker 1 0.042 0.008 0.004 0.054 — — MuUet 5 0.027 0.017 0.004 0.048 — — SAMPLING AREA 7— MOREHEAD CITY, N. C. Blue crabs 15 0.012 _ 0.001 0.013 _ — Shrimp 1 kg 0.001 — 0.001 0.002 — — Oysters 24 0.039 0.017 0.006 0.052 0.02 — Clams 20 0.003 0.002 0.003 0.008 — — Scallops 12 0.002 — 0.006 0.010 — — Flounder 3 0.030 — 0.010 0.040 — — Spanish mackerel 2 0.050 — 0.060 0.110 — — Weak fish 2 0.08(1 — 0.120 0.200 — — Blue fish 2 0.132 — 0.101 0.233 — — Mullet 5 0.115 0.082 0.189 0.386 _ — Other 10 O.OIO 0.004 0.008 0.022 — — Fish meal 0.5 kg 0.095 0.050 0.060 0.205 0.11 — SAMPLING AREA 8— CHESAPEAKE BAY Blue crabs 25 0.019 0.011 0.012 0.042 0.02 Weak fish 3 0.459 0.177 0.172 0.798 0.49 — Striped sea bass 3 0.027 0.005 0.011 0.043 0.02 _ Spot 5 0.017 0.018 0.028 0.053 0.10 — Herring 10 0.006 0.006 0.006 0.018 — — SAMPLING AREA 9— DELAWARE BAY Blue crabs 15 0.128 0.056 0.046 0.230 0.13 Flounder 2 0.023 — 0.021 0.044 0.07 — Weak fish 5 0.479 0.059 0.044 0.582 0.23 _ Striped bass 2 0.046 0.007 0.033 0.086 0.07 — Mullet 5 0.800 0.180 0.120 1.100 0.21 — Other 2 1.295 0.550 0.630 2.475 1.17 — Croaker 1 0.060 0.030 0.060 0.150 0.50 — Minus sign { — ) denotes no residues found at lowest level of detection: 0.001 ppm for DDT. 0.005 ppm for Mirex, 0.01 for Aroclor 1260. Vol. 7, No. 3/4, March 1974 143 RESIDUES IN FISH, WILDLIFE, AND ESTUARIES Mirex Residues in Selected Estuaries of South Carolina — June 1972 ^ p. W. Borthwick," G. H. Cook,' and J. M. Patrick, Jr.= ABSTRACT Estiiarine sedimenis, crabs, shrimps, and fislies were collected in June 1972 at eleven stations two years after aerial ap- plications of mirex bait for control of fire ants in coastal areas near Charleston. S.C. These stations had previously been monitored (October 1969 to June 1971) when levels of mirex in animal samples were: crabs, 0-0.60 ppm: shrimps. 0-1.3 ppm: and fishes, 0-0.82 ppm. The recent study showed that mirex was present in three species of fishes (white catfish. 0.021 ppm: bluegill. 0.047 ppm: carp, 0.12 ppm) and blue crabs (0.026 ppm) at two freshwater stations. However, mirex was not detected in 36 animal samples, most of which were talSO,, and allow to stand for 45-60 minutes with occasional stirring until powder is dry. 3. Pack powder lightly in a glass column (22-mm in- side diameter by 30 cm) fitted with a fritted glass disk. Elute column with 200 ml methanol:phos- phoric acid (99:1, v/v) (/;). 4. Place eluate in a 1 -liter separatory funnel containing 500 ml deionized water, and adjust pH to 4.5. 5. Add 100 ml petroleum ether to separatory funnel and shake vigorously for 2 minutes. Draw off petro- leum ether, and repeat the ether extraction two more times. 6. Acidify water-methanol mixture to a pH of 1.5 with concentrated H^SO,. Extract mixture three times with lOO-ml portions of diethyl ether. 7. Pass diethyl ether extract through glass column containing 12 cm anhydrous NaoS04, and collect ether in a 500-ml round-bottom flask. 8. Evaporate ether just to dryness on a rotary evap- orator. 9. Follow procedure as outlined for water samples beginning with step 4. Recovery from spiked samples was 90 ± 2.5%. Note; if large quantities of fat or pigment are present in extracts, a preliminary extraction before step 4 may be done by putting the methanol-water extract into water adjusted to pH 8 with sodium bicarbonate and extract- VoL. 7, No. 3/4, March 1974 ing with petroleum ether. The aqueous extract may then be adjusted to pH 4.5 and extracted with petroleum ether. Caution! There will be violent gas evolution at this stage. Supplement D Procedure for cleaning up 2,4-D acid residues derivatized with diazomethane. 1. Place glass-wool plug in bottom of glass column (22-mm inside diameter by 30 cm). Add 8 cm silica gel (Brinkman #7754, Brinkman Instruments, Inc., Cantiague Road, Westbury, New York 11590) and 2 cm anhydrous NanSO,. 2. Rinse column with 150 ml benzene. Discard eluate. Quantitatively transfer 2,4-D methyl ester from round-bottom flask to top of column. 3. Elute column with 180 ml of 2% diethyl ether in benzene. Collect eluate in porcelain casserole and evaporate to a small volume on a hot plate in a hood. 4. Transfer 2,4-D methyl ester to suitable container, and bring up to volume for analysis by gas chroma- tography. The gas chromatograph used for the residue analyses was a Perkin-Elmer Model 800 equipped with a Tracor Electrolytic Conductivity Detector. The column was coiled glass, 6-ft-by-'/8-inch inside diameter, packed with 10% DC-200 on Gas-Chrom Q (80-100 mesh). Column temperature was 180° C, injector temperature 220° C, venting block 265° C. and pyrolysis furnace 840° C. Retention time for the methyl ester of 2,4-D under these conditions was about 2.2 minutes. Detection limit of the 2,4-D methyl ester was 1.25 ng with 15 ng giving a 50% deflection on the recorder. Detection limit for fish samples; 0.01 mg/kg: for hydrosol; 0.005 mg/kg: and water; 0.001 mg/liter. Confirmatory analyses of the 2,4-D methyl ester stand- ard, spiked samples, and periodic samples were con- ducted by electron capture detection on a Beckman GC- 4 gas chromatograph. A cknowledgment The authors gratefully acknowledge the assistance of personnel at Loxahatchee National Wildlife Refuge for collecting samples and data, and of John Oberheu, Wild- life Biologist, U.S. Fish and Wildlife Service, Atlanta, Georgia, for coordinating the study. Analytical samples and commercial formulations of 2.4-D used in the analytical phase were supplied through the courtesy of Amchem Products, Inc., Ambler, Pa. 151 LITERATURE CITED (/) Mullison, W. R. 1970. Effects of herbicides on water and its inhabitants. Weed Sci. 18: 738-750. (2) American Public Health Association. 1971. Standard methods of the examination of water and wastewater. Ed. 13, 874 pp. (3) Smith, G. E. and B. Isom. 1967. Investigations of effects of large-scale applications of 2,4-D on aquatic fauna and water quality. Pestic. Monit. J. 1: 16-21. f-^) Wojtalik, T. F., et al. 1971. Monitoring ecological con- ditions associated with wide-scale applications of DMA 2,4-D to aquatic environments. Pestic. Monit. J. 4: 184- 203. (5) Aly, O. M. and S. D. Fausl. 1964. Studies on the fate of 2,4-D and ester derivatives in natural surface water. J. Agr. Food Chem. 12: 541-546. (6) Loos, M. A. 1969. Phenoxyalkanoic acids, pp. 1-50. In P. C. Kearney and D. D. Kaufman (ed.). Degrada- tion of Herbicides. Marcel Dekker, Inc., New York. (7) Menzie, C. M. 1969. Metabolism of Pesticides. U.S. Fish Wildl. Serv., Spec. Sci. Rep. Wild!. 127: 1-487. (S) Howard, S. F. and G. Yip. 1971. Diazomethane meth- ylation of a mixture of chlorophenoxy acids and di- nitrophenols. J. Ass. Oflfic. Anal. Chem. 54: 970-974. (9) Woodham, D. W., et al. 197 1. An improved gas chroma- tographic method for the analysis of 2,4-D free acid in soil. J. Agr. Food Cherfi. 19: 186-188. (10) Benville, P. E. and R. C. Tindlc. 1970. Dry ice homoge- nization procedure for fish samples in pesticide residue analysis. J. Agr. Ftx>d Chem. 18, 948-949. (//) Hesselberg, R. J. and J. L. Johnson. 1972. Column ex- traction of pesticides from fish, fish food and mud. Bull. Environ. Contam. Toxicol. 7: 115-120. 152 Pesticides Monitoring Journal Nationwide Organochlorine and Mercury Residues in Wings of Adult Mallards and Black Ducks during the 1969-70 Hunting Season Robert G. Heath' and Sharon A. HilP ABSTRACT Nationwide monitoring of organochlorine and mercury res- idues in wings of approximately 5,200 adult mallards and black ducks bagged during the 1969-70 hunting season showed DDE, as in 1965 and 1966, to be the predominant residue. PCB's were next in overall prevalence, followed by mercury, DDT, dieldrin, DDD, and heptachlor epoxide. There was no indication of a decrease in levels from 1966. Residues were generally highest in the Atlantic and Pacific Flyways and lowest in the Central Flyway: PCB's, however, were highest in the Atlantic Flyway and diminished west- ward across the Nation. Mercury residues were highest in Atlantic Flyway black ducks. Monitoring results were con- sistent: States with high residues in 1965 and 1966 were again high in 1969. Analyses of individual wings of mallards from California and black ducks from New Jersey and New York revealed DDE residues as high as 41 ppm and certain regional and seasonal differences in levels within Stales. They also revealed an apparent tendency for DDE residues to be more variable and to attain higher levels in male than in female wings. Introduction The first nationwide monitoring of pesticides in water- fowl occurred in early 1966 when the U.S. Department of the Interior Bureau of Sport Fisheries and Wildlife assessed organochlorine residues in wings of approxi- mately 12,000 mallards (Anas platyrhynchos) and black ducks {Artas ruhripes) bagged during the 1965-66 hunt- ing season. Monitoring was repeated a year later with a similar number of wings from the 1966-67 hunting season, and the data from the two years were combined to provide base readings for measuring trends in future residue levels (/). Monitoring was thereafter scheduled ' U.S. Department of the Interior — Bureau of Sport Fisheries and Wild- life. Patuxent Wildlife Research Center. Laurel, Md. 20810. ' WARF Institute, Inc., 506 N. Walnut St., Madison, Wise. 53701. Vol. 7, No. 3/4, March 1974 at 3-year intervals to serve this purpose. The undertaking is a segment of the National Pesticide Monitoring Pro- gram; the Bureau's current commitment in that pro- gram is described by Dustman et al. (2). Wings of approximately 5,200 adult mallards and black ducks bagged during the 1969-70 hunting season have been monitored. Findings of that survey are presented in the following report, which includes: (a) average wing levels of DDE, DDT, DDD, dieldrin, PCB's, and mercury among birds bagged in each State; (b) a com- parison of 1969-70 levels of DDE and dieldrin with the earlier 2-year averages (DDT and DDD comparisons are biased by earlier PCB interference); and (c) a special study of individual wings from California, New Jersey, and New York to compare residues among birds bagged in different periods and regions within each State. The wings used in monitoring are a by-product of an established nationwide survey in which, each fall, selected waterfowl hunters mail the Bureau tens of thousands of duck wings for biological examination. An appraisal of their suitability as a medium for monitoring was presented earlier {1,3). Methods NATIONWIDE MONITORING Wings from the 1969-70 waterfowl season were mailed by hunters to one of four regional collection points and held in frozen storage for biological examination in early 1970. Hunters reported the date. State, and county of kill for each wing, and biologists determined the species, sex, and maturity of the bird. Wings of adult mallards from most States, and of adult black ducks from eastern States, were retained for monitoring fol- lowing biological examination. 153 For practicality, monitoring in 1970 was restricted to adult wings; of those chemicals consistently detected in the earlier monitoring (DDE. DDT, DDD, and dieldrin), only DDE proved to have higher residues in adult wings than in immature wings. DDE levels in adults are of particular concern because the chemical has been shown experimentally to cause eggshell thinning in both mallards (4. 5) and black ducks (6). As in earlier monitoring, the wings from each State were sorted systematically into pools of 25 each, and a ran- dom sample of pools roughly proportional in number to the State's mallard or black duck harvest was then selected for chemical analysis. Pools not selected were discarded except for certain mallard wings from Cali- fornia and black duck wings from New York and New Jersey which were retained for individual analyses (see Findings, this paper). Each pool or individual wing was enclosed with an individually numbered tag in a plastic bag, packaged in dry ice, and shipped for chemical analysis to WARP Institute. Inc.. Madison, Wisconsin. Wing material was identified only by a code number during chemical analysis. INDIVIDUAL WINGS In earlier monitoring, variation in pool levels of DDE within certain States with the highest averages was suffi- cient to indicate that some birds carried residues con- siderably higher than the respective average. To in- vestigate this likelihood, selected mallard wings from California and black duck wings from New Jersey and New York were analyzed individually to compare resi- dues among birds bagged in different regions of the State and/or during different periods of the hunting season. Regions and periods were chosen, hopefully, to maximize any contrasts in levels. It was hypothesized that residues for these States would tend to be higher in birds taken early in the season when, prior to full-scale migration, the population comprised a higher propor- tion of local birds. In California, wings were collected from three regions: a northeast region comprising Lassen, Siskyou, and Modoc Counties, a second region comprising the coun- ties of the Sacramento Valley, and a third region com- prising counties of the San Joaquin Valley. These areas were sampled October 18-Novemher 15, 1969, and January 1-10, 1970. The northeast region, devoted largely to ranching, was expected to yield birds with residues lower than those in birds from the two Valley regions of intensive agriculture to the south. Residues in black ducks from New Jersey and New York were investigated conjunctively with samples of 28 and 34 wings. In New Jersey, which was not region- alized, wing residues in birds from coastal counties bagged October 13-26 were compared with those bagged December 13-27. New York was regionalized into Long Island and upstate New York. To investigate whether residues were higher in birds from coastal New Jersey and Long Island than in birds from upstate New York, the latter were sampled October 1 3-26 for simultaneous comparison with New Jersey, and November 17-30 for comparison with birds bagged concurrently on Long Island. CHEMICAL METHODOLOGY Preparatory to analysis, wings were trimmed by re- moving the distal joint and most of the feathers. The remaining portions were chopped and blended into 25-wing homogenates with a Hobart food chopper. A 40-g aliquot of homogenate was removed for pesticide and PCB analysis, and a separate 10-g aliquot was taken for mercury analysis. The 40-g aliquot was dried at 40°C to constant weight, ground with anhydrous sodium sulfate, and extracted in a Soxhiet for 8 hours with 300 ml of a mixture (70:170) of ethyl ether:petroleum ether. The extract was eluted through a standardized Florisil column with 250 ml of a mixture (3:1) of hexane: benzene, partitioned into acetonitrile, and passed a second time through a Florisil column. The eluate was concentrated and made to volume. Half the Florisil eluate was used to measure organochlorine pesticides, and the second half was reserved for PCB analysis, lipids were measured by drying a 25-ml aliquot of the Soxhiet extract. Organochlorine pesticides were quantified as follows: Using thin-layer chromatography (TLC), samples were plated on glass-backed Chrom AR 7GF 20 x 20 pre- poured plates. The pesticides and PCB's were developed and separated into four zones on each plate as described by Mulhern (7), except that hexane was used as the developing solvent instead of hexane:ethyl ether. Each zone was analyzed on a 3% OV-17 column, with con- firmation on 5% DC-200 and 3% XE-60. Operating specifications are shown in Table 1. TABLE 1 . — Clu-on\atograpiuc operating specifications using electron ciipliire detection Columns: G LASS, 4-FT-BY-4-MM INSIDE DIAMETER Liquid Phase 3% OV-17 S^r DC-200 3T.XE-50 Support Gas Chrom Q Gas Chrom Q Gas Chrom Q Mesh size 100/120 80/100 60/80 Temperature 190°C I90°C I70°C Retention time. 3.5(dieldrin) 6-8(p,p'-DDT) 10-12(p.p'-DDT) minutes PCB determinations were derived using semiquantita- tive thin-layer methods (8), with the modification that 0.1 g instead of 1.0 g AgNO;. was used in making the plates. All PCB samples were read by comparison of total area with an Aroclor 1254 standard. Total mercury was determined by cold vapor atomic absorption. The 10-g aliquot was digested by refluxing 154 Pesticides Monitoring Journal with a mixture of sulfuric and nitric acids (9). A mixture of hydroxylamine, stannous chloride, and sulfuric acid was added to the digest to reduce the mercury (II) ions to mercury metal. Samples were aerated (3 liters/ min) and passed through the absorption cell. All residues have been expressed on a wet-weight basis. Limits of sensitivity were 0.02 ppm for organochlorine pesticides. 0.03 ppm for total PCB's, and 0.05 ppm for mercury. Conversion of residue levels to ppm dry weight or ppm lipid weight may be approximated by dividing a given wet-weight value by 0.57 or by 0.13, the respective mean proportions of dry or lipid material in each sample. Precise measurements of dry and lipid proportions for specific samples are available upon request. The recovery efficiency of the analytical procedures was evaluated by analyzing nine 40-g aliquots of homogenized wing material known to contain only trace quantities of residues. Three of the aliquots remained untreated, three were identically spiked with low levels of five chemicals, and three were spiked with high levels. Spiking included 0.5 ppm or 1.0 ppm p.p'-DDT, 0.1 ppm or 0.2 ppm p,p'-DDD, 3.0 ppm or 5.0 ppm p,p'- DDE, 0.06 ppm or 0.2 ppm dieldrin. and 0.5 ppm or 5.0 ppm PCB as Aroclor 1254. DDT was recovered at an estimated rate of 86%, DDD at 81%, DDE at 96%, dieldrin at 88%, and PCB at 123%. Recovery efficiency for mercury was 97%; the median difference among duplicate analyses of 15 pools was 0.01 ppm mercury, and the coefficient of variation was 22.7%. None of the reported residue data have been adjusted for rates of recovery. Findings NATIONWIDE MONITORING Average residue levels (ppm wet weight) of DDE, DDT, DDD, dieldrin, PCB, and mercury in wings of adult mallards or black ducks in late 1969-early 1970 are listed in Table 2 by State where collected. The table also lists the 2-year averages (1965-66) for DDE and dieldrin, as well as the sample size, range, and standard error associated with each average. States are listed in north to south order within each of the water- fowl flyways (Atlantic, Mississippi, Central, and Pacific) to facilitate geographic comparisons. Table 3 lists the flyway averages for the same chemicals and periods, the averages having been derived by weighting each of the State averages by the estimated State bag of the species. DDE again proved to be the predominant organo- chlorine residue in mallard and black duck wings. It was present in measurable amounts in every pool, ranging in concentrations from a low of 0.06 ppm in a mallard pool from Nebraska to a high of 5.27 ppm in a black duck pool from New Jersey. State DDE averages ranged from 0.09 ppm in South Dakota mal- lards to 3.42 ppm in New Jersey black ducks. There was no indication that DDE levels were diminish- ing during the 3-year period from 1966 to 1969. Resi- dues tended to remain stable in the Pacific and Central Flyways; an apparent increase in the latter was due largely to an unusually high Texas reading. DDE levels tended to have increased in mallards from the Mississippi and Atlantic Flyways; averages were higher in 18 of 21 States. Changes in DDE levels in black ducks were mixed, although there was a tendency for levels to be higher in 1969. Geographically. State and regional contrasts in DDE levels seen in earlier wing monitoring were again prevalent. Levels in black ducks from the contiguous Atlantic Flyway States extending from New Hampshire to Delaware were among the highest in the survey, although increases in birds from Virginia. North Caro- lina, and South Carolina resulted in levels nearly as high as those to the north. The highest average DDE residues in the nation occurred in birds from New Jersey, where wings of black ducks averaged 3.42 ppm and mallards 2.62 ppm. Residues were again high in mallards from Alabama (1.75 ppm), California (1.52 ppm), Utah (1.29 ppm), Pennsylvania (1.48 ppm). and New York (0.99 ppm). Mallard wings from certain of the Central Flyway States (Montana, Wyoming, South Dakota, Nebraska, Kansas, and Oklahoma) again car- ried the lowest DDE residues, averaging from 0.09 ppm in South Dakota to 0.15 ppm in Oklahoma. DDT residues averaged from approximately one-fifth to one-tenth as high as those of DDE, the highest DDT averages occurring in Utah mallards (0.28 ppm) and New Jersey black ducks (0.27 ppm). Residues of DDD seldom exceeded trace levels. DDT and DDD residues should not be compared with those from earlier wing monitoring, because interference from certain PCB isomers undoubtedly inflated the earlier readings. Dieldrin levels in mallard wings showed little change from 1965 and 1966 monitoring. The apparent increase in black duck residues in the Atlantic Flyway could not be substantiated statistically because of variability in the data. The highest dieldrin levels were again found in wings from the Atlantic Flyway; the highest averages were in black ducks from Maine (0.44 ppm). Mas- sachusetts (0.18 ppm). Connecticut (0.16 ppm), Rhode Island (0.26 ppm). and Pennsylvania (0.16 ppm). Diel- drin averaged 0.14 ppm in mallards from Pennsylvania, the only State of the above five from which mallards were sampled. Dieldrin averaged approximately 0.18 ppm among black ducks for the three-State area of Virginia and the Carolinas, although residue levels among pools varied more than in the northern group of States. In the remaining flyways. State dieldrin averages exceeded 0.05 ppm only in Ohio, Alabama, Arkansas, Vol. 7, No. 3/4, March 1974 155 Texas, and Utah. All States except Ohio had been noted for prevalence of dieldrin in previous wing monitoring. Dieldrin and DDT levels were comparable in black ducks; whereas in mallards, dieldrin residues were na- tionwide somewhat less than those of DDT. With few exceptions, dieldrin residues exceeded those of DDD. Heptachlor epoxide was detected in most pools and in every State except Vermont. Few pools contained levels exceeding 0.02 ppm: therefore the chemical was ex- cluded from the tables. No other organochlorine residues of pesticidal origin were reported. PCB levels exhibited pronounced geographic differences, being highest in the Atlantic Flyway and generally diminishing westward. Residues were highest from New Hampshire southward through Delaware. The highest average PCB levels in the entire survey were found in black ducks from Connecticut (3.88 ppm) and Mas- sachusetts (2.12 ppm). State averages exceeded 0.50 ppm throughout the Atlantic Flyway except in black ducks from Maryland (0.39 ppm). PCB levels in the Mississippi Flyway were highest in birds from States bordering the Great Lakes, diminishing southward in all States except Tennessee. Levels were comparably lower in the Central and Pacific Fiyways, averaging overall about 0.15 ppm. The relatively high Nevada average (0.73 ppm) needs further investigation, and the low California average (0.04 ppm) may reflect the fact that there is little heavy industry in that part of the State most frequented by mallards. Mercury residues of at least 0.05 ppm were detected in all pools of wings. However, levels exceeded 0.50 ppm in only three pools, one each from New York (black ducks, 0.80 ppm), Wisconsin (1.0 ppm), and Nevada (0.55 ppm). Mercury levels in mallards were comparable in all fiyways, averaging about 0.10 ppm. Black ducks from the Atlantic Flyway averaged nearly double this level of mercury; averages were slightly higher from Delaware northward. INDIVIDUAL WINGS. CALIFORNIA In the following comparisons of residues in wings of individual mallards from California, sexes have been segregated (Table 4). Residues, especially DDE, in a given group of wings tended to be more variable and exhibit higher levels in male than in female wings, al- though females might have the higher median level. Because underlying statistical distributions were not well understood, all tests of significance have been based on nonparametric methods (10, 11). In California, as hypothesized, DDE residues in certain mallard wings greatly exceeded the State mean of 1.52 ppm (Table 4). There were also demonstrable differences in average DDE levels between certain seasonal and regional groups of wings. Levels were highest in the sample of 1 1 Sacramento Valley males taken during the early period, when the highest proportion of local birds was expected to be in the population; levels ranged from 0.49 ppm to 41.72 ppm, exceeding 3.40 ppm in 7 of 1 1 wings. To the south, residues in all six early- period males from the San Joaquin Valley exceeded 0.30 ppm, and one wing contained 20.10 ppm DDE. However, in the five early-period males from the north- east counties where ranching predominates, DDE did not exceed 0.30 ppm except in one wing (6.60 ppm). The difference between the average level for Sacramento Valley males and that for males from the northeast counties was statistically significant (P = 0.05), and the difference between San Joaquin County males and those from the northeast approached significance (P < 0.10). A significant difference could not be shown between the two Valley regions. In parallel early-period comparisons of DDE residues in female wings, the average level for the San Joaquin Valley was significantly higher (P <0.01) than that for the northeast counties. Comparisons involving Sacra- mento Valley females were restricted by a shortage of wings. Regional comparisons of late-period DDE levels neces- sarily excluded the northeast region where wings were unavailable. The tendency for levels in late-period males to be higher in the San Joaquin Valley (range 0.32- 30.65 ppm) than in the Sacramento Valley (0.18-7.13 ppm) was not statistically significant; there were not enough female wings for meaningful comparison. Seasonal comparisons could be made only within the two Valley regions since late-period wings from the northeast counties were unavailable. In males from the Sacramento Valley, average DDE levels during the early period were significantly higher (P<0.01) than during the late period; levels in 7 of 1 2 wings from the late period were below the lowest level encountered among the 1 1 early-period wings. No similar difference was demon- strable in male wings from the San Joaquin Valley, perhaps because relatively fewer migrants winter in the San Joaquin Valley than in the Sacramento Valley. Female wings were too few in number for meaningful comparisons of seasonal differences within either Valley region. DDE residues in female wings did not exhibit the ex- treme levels detected in males; differences were ap- parently due to more than the fact that the sample comprised 39 males compared to 21 females. DDE ex- ceeded 3.00 ppm in only 2 of 21 female wings (4.67 and 3.79 ppm); however, residues exceeded 3.00 ppm in 13 of 39 male wings, the 4 highest of which were 41.72, 30.65, 20.10, and 12.37 ppm. Despite such values, median DDE levels were higher for females in three of the five regional — period groups. 156 Pesticides Monitoring Journal INDIVIDUAL WINGS, NEW JERSEY AND NEW YORK As with California mallards, sexes were segregated so far as possible in comparing wing residues among in- dividual black ducks from New Jersey and New York (Table 5). Within the set of wings from a given region and period, DDE levels appeared to be higher in male wings than in wings from females or birds of un- identified sex, although differences were not statistically significant, nor so pronounced as in California mallards. As hypothesized, DDE residues tended to be higher in wings of birds taken in coastal counties than in those from inland counties. The average DDE level in males sampled from coastal New Jersey October 17-26 was significantly higher (P<0.01) than in males from upstate New York during the same period: levels in six of nine New Jersey wings ranged from 3.04 to 13.79 ppm, whereas the highest level in eight New York wings was 2.20 ppm DDE. Similarly, levels in four males from Long Island bagged November 17-30 exceeded those in four males from upstate New York taken dur- ing the same period (P<0.02). The same comparisons for female wings showed tendencies similar to those for males, but differences were less pronounced and merely approached statistical significance. Seasonal differences in DDE levels could not be demonstrated either in New Jersey or in upstate New York; Long Island was sampled during only one period. For New Jersey, the average DDE level for males taken December 13- 27 was numerically lower than for those bagged October 17-26, but the difference was not statistically significant. Female wings were inadequately represented for comparison. Disciissipn From the data in Table 2, a multitude of statistical comparisons of residue levels is possible both between States and between years within States. In many in- stances differences clearly are either significant or not significant. Caution is suggested, however, when the distinction is not clear-cut: the individual pool values may facilitate a more rigorous test of significance than is possible using pool means and their standard errors. Caution is also suggested in combining data from adjacent States unless the data have been properly weighted. Individual pool values and weighting factors are available on request. The precision with which these wing monitoring data can be interpreted has been questioned at times be- cause of the mobility of mallards and black ducks during migration and the subsequent difficulty in as- sociating wing residues with specific geographic loca- tions. The subject has been discussed in previous papers (/, 3). but further elaboration is perhaps warranted. The foremost objective in monitoring wings of mallards and black ducks is to quantify not only levels, but also trends in levels of pesticides and pollutants in continental populations of these highly valued waterfowl. Trends may be either in time or space. As stated earlier (1), "Essentially, we are monitoring flyway as well as State populations, the wings from each State being a sample of that part of a flyway population frequenting the State during the hunting season." It was also stated (3), ". . . the mobility of the species might permit only a general location of the source of contamination, [but] monitor- ing of localized material (soil, crops, etc.) by other agencies should help identify such concentrations." The same general problem exists in monitoring other motile media, whether air, flowing water, or a migratory species: however, a medium need hardly be fixed in space to warrant monitoring. Several factors support the hypothesis of positive as- sociation between average residue levels in wings from a State and average levels in at least that portion of the State's aquatic environment frequented by water- fowl. These factors include consistency of wing moni- toring data, consistency of migration patterns of adult ducks (12). and, in general, rapid dietary assimilation of organochlorine residues (13, 14). Summary Nationwide monitoring of organochlorine compounds and mercury in wings of adult mallards and black ducks from the 1969-70 hunting season showed that all resi- dues, except those of PCB's, were highest in the two coastal flyways. intermediate in the Mississippi Flyway, and lowest in the Central Flyway. PCB residues followed a similar pattern except in the Pacific Flyway, where residues were generally the lowest in the nation. DDE was again the predominant residue. Average levels failed to suggest a decrease from 1966 and, in fact, in- creased in mallards in 18 of 21 States sampled in the Atlantic and Mississippi Flyways. No changes in dieldrin levels could be substantiated statistically, although the average level appeared to increase in the Atlantic Fly- way. PCB and mercury were not previously quantified, and DDT and DDD should not be compared with earlier measurements because they undoubtedly include some PCB contamination. Analyses of individual mallard wings from California and black duck wings from New Jersey and New York for residues of organochlorine pesticides revealed DDE residues as high as 41 ppm in the mallards and 13.8 ppm in black ducks, whereas the highest respective DDE levels among 25-wing pools were 2.70 ppm and 5.27 ppm. Analyses of individual wings from California showed that residues were higher in birds from the in- tensively cultivated Sacramento and San Joaquin Valleys than from the northeastern ranching counties. In New Jersey and New York, birds from the coastal counties contained significantly higher residues than did those Vol. 7, No. 3/4, March 1974 157 from upstate New York. In both instances the data suggest a tendency for residues to be more variable and attain higher levels in male than in female wings, al- though the median level might be higher in the female wings of a given set. A cknowledgments We acknowledge the cooperation of personnel of the USDI Bureau of Sport Fisheries and Wildlife. We are especially indebted to Dr. J. B. Elder, Division of Wild- life Services, who supervised sampling operations in the Mississippi and Central Flyways, and to Mr. D. J. Lenhart, Division of Wildlife Services, and Mr. J. W. Spann, Division of Wildlife Research, for participation in sampling operations and in the survey of individual wings. Wings were provided through the cooperation of Mr. S. M. Carney, Office of Migratory Bird Manage- ment. Mrs. H. L. Young compiled the tables and per- formed the many statistical computations. LITERATURE CITED (/) Heath, R. G. 1969. Nationwide residues of organochlo- rine pesticides in wings of mallards and black ducks. Pestic. Monit. J. 3(2): 115-123. (2) Diislman. E. H.. W. E. Martin. R. G. Heath, and W. L. Reichel. 1971. Monitoring pesticides in wildlife. Pestic. Monit. J. 5(1): 50-52. (i) Heath, R. G., and R. M. Proiity. 1967. Trial monitoring of pesticides in wings of mallards and black ducks. Bull. Environ. Contam. Toxicol. 2(2): 101-110. {4) Heath, R. G., J. W. Spann, and J. F. Krcitzer. 1969. Marked DDE impairment of mallard reproduction in controlled studies. Nature 224(5214): 47-48. (5) Heath, R. G., J. IV. Spann. J. F. Kreilzer, and C. Vance. 1972. Effects of polychlorinated biphenyls on birds. Pp. 475-485 In PriK. XV International Ornithological Congress. The Hague, The Netherlands. Aug. 30 — Sept. 5, 1970. K. H. Voous, Ed., E. J. Brill, Leiden: viii -|- 745 pp. (6) Longcore. J. R., F. B. Samson, and T. W. WJiittendale, Jr. 1971 . DDE thins eggshells and lowers reproductive success of captive black ducks. Bull. Environ. Contam. Toxicol. 6(6): 485-490. (7) Miilhern, B. M. 1968. An improved method for the separation and revival of organochlorine insecticides from thin-layer plates. J. Chromatogr. 34: 556-558. {8) Midhcrn. B. A/.. E. Cromartie, W . L. Reichel, and A. A. RcUsle. 1971. Semiquantitative determination of poly- chlorinated biphenyls in tissue samples by thin layer chromatography. J. Assoc. Off. Anal. Chem. 54(3): 548- 550. (9) Monk, H. E. (Chairman). J. A. Pickard. N. A. Smart, S. H. Yuen. E. W. Atkins, A. S. Blidas. T. E. Burke, H. Crossh'x. H. Egan. P. W. Lloyd, and E. J. Miller. 1961. Recommended methods of analysis of pesticide residues in foodstuffs. Report by the Joint Mercury Residues Panel. Analyst 86: 608-614. [10) Siegcl. Sidney. 1956. Nonparametric statistics: for the behavioral sciences. McGraw-Hill, Inc., N.Y., N.Y. 312 pp. (//) WUcoxon, E., and R. A. Wilco.x. 1964. Some rapid ap- proximate statistical procedures. Lederle Laboratories, Pearl River, N.Y. 60 pp. (12) Bellrosc, F. C. 1968. Waterfowl migration corridors east of the Rocky Mountains in the United States. 111. Natur. Hist. Surv. Biol. Notes No. 61, 24 pp. (13) Diiidal, D. L. 1970. Accumulation and excretion of CI" DDT in mallard and lesser scaup ducks. J. Wildl. Manage. 34(1): 74-92. (14) Slickel, W. H., L. E. Stickel. and E. B. Coon. 1970. DDE and DDD residues correlated with mortality of experimental birds. Pp. 287-294 In Pesticides symposia, W. B. Deichmann, Ed. 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Ui z < s z w S5 ^^ o X P:^ UJ D w z i u ^ s 2 0. a. Z LU Q in 0 5 S o: Q Si U £' z U IS oe Q 2 ^ w w 1- 5 u Q UJ "^ Q z < S . B^ D O ■ S i3 '7 t« w ^ w S^ *- •r o O 1/1 4J ■-■roup a c o o fM O d d d f^ d d On m ri ON %0 r*^ d d '+ ^ + r'^H- 3 ON Ov O On ON a2£ " rt -o ^ ^ H Q ii -3; ■o C C u o 5 C n '-' n c Q ■« ON ■= > H - 1 g 5e^"s UsE!i.2 0 0 o E =5 =■ a t3 nU >,5 < E ES s j; -J D.w£ 0. 162 Pesticides Monitoring Journal TABLE 3. — Mean residues' of DDE, DDT, DDD, and dichlrin. hy waterfowl fiyways, in pools of 25 wings of adult mallards or black ducks in 1969 and in 1965-66; and residues of PCB's and mercury in 1969 Fl.YWAY Year No. OF POOLS Residues, ppm (WET WEIGHT) DDE DDT DDD DiELDRIN PCBs Mercury Species Mean Std. error Mean Std, ERROR Mean Std. ERROR Mean Std. ERROR Mean Std. ERROR Mean Std. ERROR Black Duck Atlantic 1969 1965-66 41 89 1.42 1.23 0.103 0.078 0.12 0.011 0.03 0.019 0.14 0.05 0.057 0.008 1.20 n.a.- 0.124 0.19 n.a. 0.022 Mallard Atlantic 1969 1965-66 18 39 1.05 0.72 0.139 0.078 0.09 0.014 0.02 0.002 0.05 0.025 1.29 n.a. 0,457 0.10 n.a. 0.004 Mallard Mississippi 1969 1965-66 51 123 0.40 0.25 0.058 0.024 0.08 0.012 (0.05) ' — 0.04 T 0.003 0.35 n.a. 0.044 0.09 n.a. 0.014 Mallard Central 1969 1965-66 49 117 0.30 0.17 0.098 0.017 0.03 0.009 T — 0.02 T 0.006 0.17 n.a. 0.039 0.08 n.a. 0.003 Mallard Pacific 1969 1965-66 51 117 0.71 0.70 0.054 0.063 0.11 1 0.012 T 0.02 T 0.005 0.13 n.a. 0.014 0.10 n.a. 0.004 1 See table 2 for limits of quantification and caution regarding DDT or DDD comparisons. " n.a. =: no analysis. 3 T = mean residue level probably lower than limit of quantification, * Parenthesized approximation involving trace residues. TABLE 4. — Pesticide residues in wings of individual adult mallards: California, 1969-70 October 18-November 15, 1969 January 1-10, 1970 Date Sex Residue, ppm (wet weight) County Date Sex Residue, ppm ( wet weight) County DDE DDD DDT DiELDRIN DDE DDD DDT DiELDRIN NORTHEASTERN COUNTIES Modoc Oct 18 M 0.13 t 1 t Siskiyou Oct 18 M 0.18 t Lassen Oct 18 M 0.20 0.02 Siskiyou Oct 19 M 0.29 0.02 Siskiyou Oct 20 M 6.60 0.42 Modoc Oct 18 F 0.26 t Modoc Oct 18 F 0.38 0.02 No January wings available Modoc Oct 18 F 0.41 0.02 Modoc Oct 18 F 0.63 0.03 Siskiyou Oct 19 F 1.08 0.14 Median M 0.20 0.02 F 0.41 0.02 SACRAMENTO VALLEY COUNTIES Sutter Oct 25 M 0.49 t 0.10 0.02 Glenn Jan 7 M 0.18 t 0.02 t Yolo Oct 18 M 0.62 t 0.09 t Yuba Jan 3 M 0.25 t 0.03 t Colusa' Oct 25 M 0.82 0.04 0.21 0.03 Colusa Jan 8 M 0.28 t 0.02 t Butte Oct 19 M 1.21 0.02 0.20 t Glenn Jan 9 M 0.31 0.02 0.04 t Sutter Oct 25 M 3.47 0.04 0.18 0.02 Butte Jan 3 M 0.44 t 0.12 0.03 Butte Oct 19 M 4.86 t 0.22 t Butte Jan 10 M 0.45 0.02 0.08 t Sutter Oct 18 M 5.05 0.10 0.26 0.06 Colusa Jan 4 M 0.48 t 0.05 t Colusa Oct 25 M 5.91 0.02 0.69 0.03 Glenn Jan 7 M 0.70 t 0.06 0.03 Yolo Oct 18 M 6.67 0.04 0.57 0.02 Colusa Jan 7 M 1.48 0.04 0.06 t Oct 25 'm 12.37 0.02 0.20 t Yolo Jan 9 M 1.62 0.02 0.33 t Glenn Oct 25 41.72 0.11 2.46 0.03 Butte Jan 9 M 2.66 0.06 0.48 t Oct 18 F 0.18 t 0.03 t Colusa Jan 7 M 7.13 0.05 0.40 0.02 Sutter Oct 18 F 0.47 t 0.10 0.02 Placer Jan 7 F 0.94 0.02 0.17 t Colusa Oct 25 F 1.45 0.03 0.55 0.03 Colusa Jan 3 F 3.79 t 0.11 t Colusa Oct 25 F 1.73 t 0.14 0.02 Butte Jan 7 F 4.67 0.41 0.72 0.03 Median M 4.86 t 0.22 t Median M 0.47 t 0.07 t F 0.96 0.02 0.33 0.03 F 3.79 t 0.11 t 1 t: residue detected at level below limit of quantification. Vol. 7, No. 3/4, March 1974 SAN JOAQUIN VALLEY COUNTIES Nov 9 M 0.32 t 0.09 0.03 Contra Costa Jan 9 M 0.32 0,05 Oct 22 M 0.58 0.02 0.07 0.02 Fresno Jan 1 M 0.44 0.08 Fresno Oct 18 M 0.66 0.02 0.15 t Merced Jan 3 M 0,60 0.05 Oct 19 M 0.86 t 0.05 t San Joaquin Jan 9 M 4.58 0.11 Fresno Nov 10 M 4.20 0.05 0.47 t Fresno Jan 1 M 30.65 0.51 6.65 0.11 Fresno Oct 22 M 20.10 t 0.23 t Merced Jan 3 F 0.13 0.03 Merced Oct 22 F 0.44 t 0.05 t Merced Jan 3 F 0.15 0.02 San Joaquin Oct 19 F 1.24 0.05 0.97 0.02 Merced Oct 18 F 1.26 0.03 0.53 0.02 Merced Nov 15 F 1.49 t 0.07 t Fresno Oct 19 F 1.51 0.04 0.39 0,02 Fresno Oct 19 F 1.78 0.02 0.17 0.12 San Joaquin Nov 8 F 2.02 0.03 0.58 0.02 Median M 0.76 t 0.10 t Median M 0.60 t 0.05 t F 1,49 t 0.07 t F 0.14 t 0.02 t 163 TABLE 5. — Pesticide residues in wings of individual adult black ducks: New Jersey and New York, late 1969 County October 17-26, 1969 December 13-27, 1969 Date Sex Residue, ppm (WET WEIGHT) County Date Sex Residue, ppm ( WTT WEIGHT) County DDE DDD DDT DiELDRIN DDE DDD DDT DiELDRIN NEW JERSEY: COASTAL AND DELAWARE BAY COUNTIES Cumberland Oct 21 M 0.51 0.02 0.08 ti Atlantic Dec 22 M 0.36 0.02 0.05 0.02 Atlantic Oct 25 M 0.86 0.02 0.13 t Cumberland Dec 13 M 0.75 0.02 0.09 0.02 Ocean Oct 20 M 1.88 t 0.05 t Cumberland Oct 26 M 0.96 0.02 0.08 0.02 Bergen Oct 18 M 3.04 0.06 0.26 0.07 Atlantic Dec 23 M 1.30 0.02 0.14 t Cumberland Oct 18 M 3.19 0.02 0.39 t o^ Hudson Dec 19 M 2.43 0.14 0.40 0.25 Cape May Oct 23 M 4.74 0.15 0.48 0.02 vC Atlantic Dec 20 M 3.44 0.03 0.36 0.03 Atlantic Oct 23 M 6.00 0.04 0.46 0.03 Ocean Dec 19 M 5.20 0.15 0.59 0.02 Atlantic Oct 24 M 8.08 0.03 0.54 t o Cape May Oct 22 M 13.79 t 0.14 t r- Bergen Oct 23 F 0.41 t 0.02 t OJ Bergen Dec 23 F 0.41 0.04 0.10 0.08 Bergen Oct 23 F 3.96 lost 0.70 0.82 > Bergen Dec 27 F 0.61 0.27 0.12 0.30 Ocean Oct 23 Unk 0.17 t 0.03 t o Z Cumberland Dec 27 Unk 0.74 0.02 0.10 0.03 Cape May Oct 25 Unk 1.83 0.03 0.04 1 ■a Cumberland Dec 24 Unk 0.98 t 0.07 t ?? Cumberland Dec 27 Unk 1.28 0.02 0.10 0.03 U Cumberland Dec 27 Unk 1.65 0.08 0.43 0.06 Cape May Essex Dec 13 Dec 26 Unk Unk 2.97 4.11 0.02 0.02 0.22 0.23 0.08 0.04 Median M 3.19 0.02 0.39 t Median M 1.30 0.02 0.14 0.02 F 2.19 0.36 0.41 F 0.51 0.16 0.11 0.19 October 17-26, 1969 November 17-30. 1969 Date Sex Residue, ppm (wet weight) County 1 Date Sex Residue, ppm (wet weight) County DDE DDD DDT DiELDRIN DDE DDD DDT DiELDRIN UPSTATE NEW YORK Wayne Oct 25 M 0.14 t t t Ontario Nov 24 M 0.30 0.04 0.02 0.02 Delaware Oct 18 M 0.15 t t t Ontario Nov 22 M 0.49 t 0.04 t Monroe Oct 24 M 0.20 t t t Ontario Nov 22 M 0.82 0.02 0.06 0.05 Schoharie Oct 26 M 0.45 1 0.03 t Niagara Nov 22 M 1.07 0.06 0.24 0.05 Dutchess Oct 18 M 0.75 0.02 0.03 0.02 Erie Oct 17 M 1.71 t 0.03 t Cayuga Nov 24 F 0.05 t t t Orange Oct 23 M 1,77 t 0.05 t Ontario Nov 20 F 0.06 t t t Washington Oct 21 M 2,20 t 0.02 t St. Lawrence Wayne Nov 30 Nov 23 F F 0.16 0.16 t t 0.04 t 0.02 t Fulton Oct 21 F 0.17 1 0.02 t Ontario Nov 23 F 0.18 t 0.02 t Seneca Oct 23 F 0.18 t 0.02 t Chautaugua Nov 30 F 0.73 0.02 0.05 0.05 Jefferson Oct 18 F 0.42 t 0.02 0.02 Ontario Nov 23 F 3.08 t 0.18 0.03 Jefferson Oct 20 Unk 0.22 Westchester Nov 17 Unk 0.28 0.02 0.03 0.03 Median M F 0.66 0.16 0.03 t 0.05 0.02 0.035 Median M 0.60 t 0.025 t t F 0.18 t 0.02 t ^ JOVEMBE R 17-30, 1 969 Sex Residue, ppm (wet weight) DDE DDD DDT DiELDRIN LONG ISLAND Nassau Nov 29 M 1.18 0.02 0.43 0.03 Suffolk Nov 24 M 1.48 0.03 0.38 0.02 Suffolk Nov 25 M 3.19 0.03 0.58 0.02 Suffolk Nov 20 M 3.24 0.08 1.11 0.04 No December wings available Nassau Nov 24 F 0.20 t 0.03 t Nassau Nov 22 F 0.27 t 0.02 t Nassau Nov 22 F 0.43 0.02 0.14 0.03 Nassau Nov 25 F 0.80 0.02 0.16 0.02 Suffolk Nov 22 Unk 0.46 0.02 0.08 0.06 Suffolk Nov 22 Unk 3.87 0.04 0.85 0.02 Median M 2.34 0.03 0.48 0.02 F 0.35 0.015 0.085 0.015 1 t: residue detected at level below limit of quantification. 164 Pesticides Monitoring Journal Organochlorine Insecticide Residues in Sediment and Fish Tissues, Ontario, Canada R. Frank,' A. E. Armstrong," R. G. Boelens," H. E. Braun,' and C. W. Douglas' ABSTRACT River and lake sediiueiils and several species of fish were collected from four study areas in the Province of Ontario. These consisted of one agricultural, two mixed agricultural — recreational, and one recreational study area. Large vol- umes of DDT and dieldrin were used in the first area, small quantities were used in the mixed areas, and insignificant quantities were used in the recreational area. The agricul- tural and mixed areas were located on deep alluvial soils; the recreational area was located on bare-to-thinly-covered Precambrian rock. Residue levels in sediments were similar in all four areas, but slightly higher in the recreational area. The ratios of DDT to its metabolites, DDE and TDE, were similar in all areas in that the metabolites predominated over the parent DDT. Residues of DDT and dieldrin in fish tissues tended to depend on feeding habits, fat content, and age of the fish. Residues in the sediment (dry weight) were almost the same as residues found in the low-fat benthic inverte- brate and plankton feeders. Residues increased in the low-fat piscivores, were slightly higher in the high-fat feeders, and were highest in the high- fat piscivores. The concentration of DDT and dieldrin in the tissues and extractable fat and the actual quantity ac- cumulated per fish increased as size and weight of any one species increased. The increase in total DDT or dieldrin concentration from lowest to highest tissue residues of all fish species was of the order of 100 to 500 times; the in- crease in body load was of the order of 10' to 10'. Higher concentrations in fish tissue were correlated with the higher sediment levels of the Precambrian recreational area. Data demonstrate that the use of even minute quantities of persist- ent chlorinated hydrocarbons in rockv Precambrian waler- ' Ontario Pesticide Residue Testing Laboratory. Ontario Ministry of Agriculture and Food, Guelpli. = Ontario Ministry of Natural Resources, Pembroke Sound, Ontario, Canada. = Water Quality Branch, Ontario Ministry of the Environment. Toronto. ' Ontario Ministry of Natural Resources, Parry Sound, Ontario, Can- ada. sheds has a profound effect on sediment and biota contam- inants. Use on deep rich soils has a similar effect, but not in the same proportion to the quantity used. Introduction The persistent organochlorine insecticides have been used for insect control over the past 25 years in the Province of Ontario. In the early years, DDT was registered for a multiplicity of uses in agriculture and forestry. During the 1950's it was used extensively by growers of tobacco, vegetables, and fruit, and was virtually eliminated from use by producers of dairy animals and other livestock. As agricultural and forestry uses became more specific, private and municipal uses became more general; DDT was used in the protection of shade trees and ornamentals and the control of biting flies in urban and recreational areas. Aldrin and dieldrin had special properties for the control of soil-borne in- sects injurious to crop production. Aldrin was used in urban areas to protect lawns, and dieldrin was used in industry to protect fabrics and timber products. The persistence of these three insecticides has been reviewed previously (/). A range of 4 to 30 years for DDT and 5 to 25 years for dieldrin has been quoted for 95% disappearance from agricultural soils in the tem- perate zone. Unfortunately, this persistence is greatly extended because DDT breaks down into two per- sistent metabolites, TDE and DDE, and dieldrin is derived from aldrin which can persist for 1 to 6 years (1). Dieldrin and DDT are of very low solubility in water (0.25 to 1.0 ppm and 0.1 to 3.7 ppb, respectively) and are tenaciously held by soil particles; hence movement through soils is insignificant (/). Movement into the Vol. 7, No. 3/4, March 1974 165 aquatic environment on soil transported by wind or water is well documented (/, 2). In the aquatic environ- ment DDT is reductively dechlorinated to TDE (3,4), especially by coliform bacteria (3, 5). One study (6) re- ported that a similar conversion occurs in soils under anaerobic conditions although normal breakdown under aerobic conditions gives rise to considerable DDE (1). River sediments containing DDT are reported (7) to give traces of DDT in water although these have been only 1/18,000 of the sediment levels. Absorption of DDT from water via the gills of fish has been re- ported {8.9) as high as 80 to 90% in the first 10 hours after application. The external mucous coating of fish was also found to concentrate DDT and aid absorption through skin. In addition to this direct absorption from water, accumulations by fish through the food chain are now well documented (10). An accumulation factor of 10.000 has been reported from water to fish, in- corporating both direct absorption and food chain con- centration. With this in mind, standards of 0.5 and 0.25 ppb have been suggested as maximum reasonable stream allowances (//). In this study four areas were selected where different patterns of DDT and dieldrin use had occurred in a four-year study: 1968-71. Residues were measured in the sediments of streams and lakes and attempts were made to correlate this to accumulations in different fish species. Study Areas Four study areas were selected in southern Ontario. Three have soils derived from glacial deposits; the fourth is on the Canadian Shield (Precambrian). Agricultural Area 1 : This study area covered the whole of Norfolk County and parts of Elgin, Oxford, Brant, and Haldimand Counties (Fig. 1). The area is char- acterized by a flat topography and deep sandy loam FIGURE 1. — Areas sampled for organochlorine residues in Southern Ontario, 1968-71. soils. Flue-cured tobacco was the major cash crop of the area with an annual production of 90,000 acres; this represents about 95% of the tobacco acreage in the Province. About 80% of the DDT and 8 to 9% of the aldrin-dieldrin used in Ontario have been applied to this area (Table 1). It is served by many creeks and tributaries to Long Point Bay. Lake Erie. Agricultural — Recreational Area 2: The area consists of an agricultural marsh with deep muck soils that drain into an adjacent lake. The area is located north of the city of Toronto and supplies that city with fresh vege- tables. The marsh drains by way of the Holland-Schom- berg River and tributaries to Lake Simcoe where the shoreline is developed for recreation and two sizable urban centers. In the past, DDT and aldrin-dieldrin were used intensively for vegetable production. The actual quantities of each were quite small (Table 1) but the rate of application per acre was high. DDT was used around the shoreline of Lake Simcoe to control biting flies. Mi.xed Agricultural — Recreational Area 3: This is a relatively large area, situated on the north shore of Lake Ontario, devoted to low-intensity mixed agricul- tural— recreational pursuits with some urban develop- ment. Belleville is the largest city in the area. The topography is undulating and the soils vary from shallow to deep and sandy to clay loam. Agriculture is confined mainly to Prince Edward County and the lakeshore of Northumberland and Hastings. Much of the hinterland and lakeshore is recreational. Several rivers serve the area, including the Trent, Moira, Napanee, and Salmon. They drain into the Bay of Quinte before entering Lake Ontario. About 3 to 4% of the DDT used in the Province is used in this area for fruit and some vegetable production. Aldrin-dieldrin use was confined largely to potato and vegetable pro- duction. At least one factory on the river system used dieldrin; the purpose was to impregnate carpets. Rcreational Area 4: The Muskoka lakes and rivers are popular recreational areas. This Precambrian area has little or no true soil and consists of lakes and rock out- crops with mixed deciduous and coniferous forest grow- ing on shallow soils and detritus trapped between rocks. The whole system drains into the Georgian Bay and thence into Lake Huron. Use of DDT in this area was exceedingly small measured against use in the other areas, occurring mainly between the late 1950's and 1966 for the control of biting flies and for minor out- breaks of caterpillars and budworms. Sediments were collected and fish were caught in gill nets from each of these four areas; samples were analyzed for DDT. its metabolites, dieldrin, and other organochlorine compounds. 166 Pesticides Monitoring Journal TABLE 1. — Quantities of DDT and aldrin/dieldrin used in four study areas, 1968-70 Insecticide Year Agricultukal Area 1 Total lb, % Agricultural — Recreational Area 2 Total lb, % Agricultural — Recreational Area 3 Total lb, % Recreational i Area 4 Total lb Total Use IN Province, LB DDT = Aldrin— Dieldrin ^ 1968 1969 1970 1968 1969 1970 246,000 (83) 365,000 (79) 154,500 (86) 263,000 (8.1) 2,500 (9.3) None 14,100 (4.8) 14,400 (3.1) 5,330 (3.0) 8.400 500 None 13,000 (4.4) 13,800 (3.0) 5,100 (2.8) 3,850 980 None None None None 30 None None 296,300 463,100 179,500 3,263,000 26,900 None 1 Last recorded use in 1966. ' Based on analysis of 5 commercial formulations, content was 75.5% = Over 95% of the aldrin — dieldrin used as aldrin. Analytical Procedures Sediments were air dried, ground, and stored until an- alyzed. Mineral and organic sediments were analyzed differently. Mineral sediments (25 g) were brought to within 50% of field water storage capacity and left for 24 hours. Acetone and hexane in the ratio 1:1 (250 ml) were added to the sediment and the mixture was shaken for two hours. An aliquot (100 ml) was filtered off, water was added, and the organochlorine insecticides were partitioned into hexane. Organic sedi- ments (25 g) were blended with acetonitrile and water (2:1) for 5 minutes and an aliquot (10 g) was filtered off. The filtrate was partitioned into hexane. Fish were held in frozen storage at — 20°C. A repre- sentative sample (10 g) of the eviscerated portion was mixed thoroughly with granular anhydrous sodium sulfate (100 g) and standard Ottawa sand (25 g) by grinding in a mortar and pestle until all tissue was finely subdivided and homogeneous. This mixture was transferred to a Soxhlet extraction apparatus and sub- jected to exhaustive extraction with hexane for 7 hours. Extracts from sediments and fish tissues were evaporated to dryness by rotary vacuum at 45°C. In the case of fish the percentage of fat or oil was determined gravimetrically. A one-step Florisil column cleanup method (12) was used for the isolation of organochlorine insecticides. Florisil (60-100 mesh) activated commercially at 650°C was reheated at 135°C for a minimum of 24 hours. After cooling, the adsorbent was partly deactivated by the addition of water at the rate of 5 ml/ 100 g and allowed to equilibrate. Up to 1 g of fat from fish extracts and 10 g of sediment extract were mixed thoroughly with 25 g of conditioned Florisil. This was placed on top of a second 25-g portion of prewashed adsorbent in pyrex columns (25 mm by 300 mm) fitted with reservoirs (350 ml). The entire column was eluted with 300 ml of the 1:4 dichloro- methane:hexane (v/v) solvent mixture at a percolation rate of approximately 5 ml per min. Eluates were con- centrated just to dryness with rotary vacuum evapora- tion at 45°C, the residue was redissolved in 5 ml hexane P'-DDT, 18.0% o,p'-DDT, 6.1% p,p'-TDE, and 0.4% DDE. and used for subsequent gas chromatographic analysis. All solvents employed were reagent grade chemicals which had been redistilled from glass. Varian Aerograph Models 204 and 1200 gas chroma- tographs, equipped with 250 millicurie tritium electron capture detectors, were used for qualitative and quan- titative assays. Operating parameters were as follows: Column: 5 ft. by 'A in. Pyrex packed with 4% SE-30 -|- 6% QF-1 on Chromosorb W, preconditioned 72 hr. at 225°C (/.*). Temperatures: column. 175°C; detector, 200°C; injection block, 225°C. Carrier gas: Nj at 40 ml/min. Injection volumes of 5 fjd were used for both sample solutions and comparison standards. Qualitative residue confirmation was accomplished mainly with thin-layer chromatography (TLC) using silica gel. Plates were developed with 1% chloroform in n- heptane, and visualized with alkaline AgNO-j spray as the chromogenic agent. Alternatively, p.p'-DDT and p.p'-TDE were confirmed by treatment with 5% meth- anolic KOH (14) to produce the corresponding de- hydrochlorinated derivatives and reidentification by gas chromatography. Dieldrin levels in general were too low for confirmation by either TLC or chemical con- version. Partial confirmation of dieldrin was achieved by fractionating the analysis solution on the Mills column (15). thus isolating dieldrin in the second eluate fraction. Percent recoveries of pesticides from fish tissue were checked periodically by fortification directly into the oil obtained as the result of the hexane extraction. Averaged recoveries were: p.p'-DDE, 97.8%; o,p'-DDT, 91.2%; p.p'-TDE. 94.6%; p,p'-DDT, 89.6%; dieldrin, 89.3%. The data presented in this report do not include corrections for percent recoveries. Polychlorinated biphenyls were isolated and measured separately in 1970 and 1971 and will be reported in a second paper. Separation was attempted in 1969 but difliculties were experienced. No separation was made in 1968. The number of samples collected in 1968 were few. Later analyses showed that from those study areas included in this paper PCB's represented no more than 5% of the gas-liquid chromatography responses to DDT and TDE and no more than 1% of the DDE. Vol. 7, No. 3/4, March 1974 167 Results SEDIMENTS A total of 314 sediments were analyzed from lakes and rivers in the four study areas. Residues of DDT, its metabolites, and dieldrin were measured in both the collective and drainage sections of each water system. Three of the study areas were situated on deep alluvial soils (areas 1, 2, and 3) and one was located on the rocky Canadian Shield (area 4). Waterways in the alluvial soils had sediment residues slightly below those on the shield (Tables 2 A,B,C,D). The range in mean 2DDT for the total systems varied from 56 to 96 ppb in the three alluvial soil areas and 157 ppb on the shield. In the rivers of areas 1, 2, and 3, the range in mean 2DDT was from 70 to 101 ppb, or about twice the residue found in the receiving bays or lakes where residues ranged from a mean SDDT of 26 to 56 ppb. In area 4, the collecting lake system had a mean residue of 170 ppb 2DDT; the draining river averaged 110 ppb. Area I: The tobacco belt is situated on deep alluvial soil and its waterways vary from very sluggish (Dedrich Creek) to quite rapid. The mean 2DDT in the river and creek sediments varied from 19 to 146 ppb and also varied greatly on a single waterway (Table 2A). Like- wise, the mean dieldrin levels varied widely from non- detectable in several bodies of water to 2 ppb in Nanticoke Creek. The highest sediment residues of DDT were in Big Creek (125 ppb) and Dedrich Creek (146 ppb), two watercourses that were either sluggish or associated with lands intensively planted in tobacco (Table 1). Statistically, these residues are significantly higher than those in the other rivers and creeks of this system. Residues of 2DDT in the bay (29 ppb) were con- siderably lower than in the river system (95 ppb), suggesting dilution and/or degradation. In most sediments o.p'-DDT as well as p,p'-DDT were found. In the formulation of DDT used in the area the ratio of these two ingredients was 4:1. In the creek sediments p.p'-DDT was 5 to 8 times the residue of o.p'-DDT; in the bay this had increased to 25 times. In the creek sediments, the ratios of DDE:TDE:DDT, including o.p' and /j./i'-DDT, were equal; in Long Point Bay, Lake Erie, however, the ratio was 2:8:1. The in- crease in DDT in the bay sediment would indicate con- siderable degradation in the bay. There was little differ- ence in the composition of DDE, TDE, and DDT in six creeks and rivers in the system (Table 2A). Area 2: Water courses in this mixed agricultural — recreational area were situated on a deep alluvial soil and were associated with a considerable area of muck soil. Most tributaries were sluggish and hence .sediment texture and pesticide residues varied markedly from location to location. Sandy gravel sediments had a mean 2DDT residue of 33 ppb and a mean dieldrin residue of 2.1 (Table 2B). Increases in residue levels appeared to be related to increased colloidal content. Organic silt had a mean SDDT of 170 ppb and a dieldrin residue of 3.2 ppb. The mean 2DDT of the whole river system was 101 ppb SDDT and 7.8 ppb dieldrin. In the lake sediments, which were largely sandy gravel, the mean 2DDT was 56 ppb: no dieldrin could be detected. Movement of these two pesticides into Lake Simcoe appeared minimal as indicated by the absence of dieldrin. Dieldrin, which was used largely for protection of vegetable crops on the marsh, appeared as residues in sediment in adjacent streams. The concentrations rose to a maximum of 137 ppb in localized sections of the river but was absent in seven Lake Simcoe sediments. DDT was used both for vegetable protection on the marsh and for controlling biting flies around the lake. Residues of DDT in the lake, therefore, were not in- dicative of downstream movement. When sandy gravel sediments from the rivers serving the marsh were com- pared with sediments of similar texture from the lake, residues of DDT and its metabolites were slightly higher in the lake sediments than in the river sediments (33 to 56 ppb). Since no clay silt or organic debris samples were collected from the lake, these could not be compared. Some of the sediments from the river contained o,p'- DDT with the p,p'-DDT; however, lake sediments con- tained only p.p'-TiDT. Although DDT was still being used in the marsh areas throughout the period of the study, its use around the lake was discontinued in 1966. In the total river system the ratios of DDE:TDE:DDT, including o.p' and /),p'-DDT, were approximately 1:3:1, and in the lake, 1:3:5 (Table 2B). If sediments from the river are compared with those of similar texture from the lake, then ratios agree more closely. These ratios would indicate slower degradation in the sandy gravels than in the silts and organics, and suggest that lake resi- dues were the result of local use rather than downstream movement. The most rapid degradation to TDE ap- peared to occur on the clay silt where ratios were 2:7:1. Area 3: Rivers were located on shallow to deep alluvial soils and all drained into the Bay of Quinte in Lake Ontario. River sediments were quite sandy but con- tained considerable organic content. Mean SDDT residues in river sediments varied from 13 to 133 ppb with an average of 70 ppb (Table 2C). Each river showed considerable variation in residue from location to loca- tion. Mean dieldrin residues varied from 0.1 to 1.5 ppb and was 0.8 ppb for the total river system. TTie highest residues of DDT were found in sediment from the Trent River (133 ppb), a river associated with the 168 Pesticides Monitoring Journal TABLE 2 A. — Residues or Digaiiochloiiiic inscclicidcs in salimcnls from rivers uiul creeks in tobacco hell and Long Point B Lake Erie (Agricultural Area 1) Number of Samples Analyzed Content in dried SEDIMENT. PPB ^ Location p,p-DDE p,p'-TDE o,p'-DDT p,p'-DDT Total DDT DiELDRIN 1. River System Big Creek & Tributaries — mean — max —min 79 46.5 560.0 ND 40.1 300.0 ND 7.4 2.95 ND 31.1 1205.0 ND 125.1 2360.0 ND 0.7 140.0 ND Dedrich Creek — mean — max — min 19 30.5 60.0 18.0 57.4 110.0 40.0 8.9 25.0 6.0 48.9 101.0 21.0 145.7 296.0 85.0 0.9 5.0 ND Big & Little Otter Creeks — mean — max — min 19 13.4 28.0 1,0 9.1 14.0 0.4 1.3 4.0 0.8 16.4 27.0 4.2 40.2 72.0 6.4 1.6 9.0 0.4 Nanticoke Creek — mean — max — min 19 17.8 55.0 5.0 22.3 134.0 9.0 3.5 3.1 0.8 14.6 25.9 3.2 58.2 218.0 18.0 2.0 12.0 ND Forestville Creek — mean — max — min 3 6.7 20.0 ND 6.7 20.0 ND ND ND ND 13.3 40.0 ND 26.7 80.0 ND ND ND ND Grand River —mean — max — min 19 5.1 8.0 0.4 4.2 2.0 0.5 1.1 14.0 ND 8.8 39.0 0.3 19.2 63.0 1.2 0.9 6.0 0.4 Total River System - — mean 158 31.4 31.4 5.5 26.5 94.8 LO 2. Bay — Lake Erie Long Point Bay = — mean — max — min 21 5.2 12.0 ND 20.9 165.0 ND 0.1 3.0 ND 2.5 8.0 ND 28.7 188.0 ND 0.6 12.0 ND Total River— Bay System — mean 179 28.3 30.1 4.8 23.7 86.9 1.0 ND; not detected. ■ ratio of DDE;TDE:DDT in river ' ratio of DDE;TDE-.DDT in Bay system was 1:1:1. was 2:8:1. TABLE 2B. — Residues of orgaiioclilorine insecticides in sediment from Holland Schomberg River- (Agricultural — Recreational Area 2} -Lake Simcoe System Location and Type OF Sediment Number of Samples Analyzed Content in drled sediment. PPB 1 p,p'-DDE P.P'-TDE o,p'-DDT P,p'-DDT Total DDT DiELDRIN \. Holland Schomberg River = Sand — Gravel — mean — max — min 11 5.8 19.0 2.0 12.5 42.0 1.0 2.2 17.0 ND 12.5 63.0 ND 33.0 141.0 3.0 2.1 12.0 ND Clay— Silt — mean — max — min 17 22.3 118.0 Trace 68.1 450.0 4.0 3.8 15.0 ND 14.7 56.0 ND 108.9 639.0 4.0 13.9 137.0 ND Organic — Silt — mean — max — min 9 33.3 219.0 2.0 119.4 846.0 2.0 ND ND ND 16.9 104.0 5.0 169.6 1169.0 9.0 3.2 11.0 ND Total River System — mean 37 20.1 63.8 2.4 14.6 100.9 7.8 2. Lake Simcoe = Sand — Gravel — mean — max — min 7 5.7 25.0 ND 16.1 70.0 ND ND Trace ND 34.3 173.0 ND 56.1 268.0 ND ND ND ND Total River— Lake System — mean 44 17.8 56.2 2.0 17.8 93.8 6.6 ND: not detected. ■■ ratio of DDE:TDE:DDT in river was 1:3:1. ' ratio of DDE:TDE:DDT in lake was 1 :3:5. greatest intensity of agricultural, industrial, and recrea- tional pursuits. The Bay of Quinte contained sediments with a 2DDT residue of 26 ppb, only one third those of the river system (70 ppb), but dieldrin residues (0.5 to 0.8 ppb) were almost as high as those of the river system. Residues of TDE predominated in sediments of all rivers of this system, suggesting that breakdown oc- curred under anaerobic conditions. Residues in the Bay of Quinte were similar to those in sediments from all rivers: the metabolites DDE plus TDE to DDT had a Vol. 7, No. 3/4, March 1974 ratio of 10:1 or greater (Table 2C). Measurable amounts of o,p'-DDT were found only in the Trent River, and were virtually absent from the river — bay system. Area 4: Lakes Muskoka, Rosseau, and Joseph are con- tiguous bodies of water that are highly developed for recreation and are located on the Canadian Shield. Resi- dues of DDT in the lake sediments varied from site to site; some were very low (3 ppb) and others were very high (1080 ppb). The mean 2DDT residues for the three lakes. Muskoka, Rosseau, and Joseph, were 25, 250, 219, and 105 ppb, respectively (Table 2D). In Lake 169 TABLE 2C. — Residues of organochlorine insecticides in sediments from Bay of Qiiinte, Lake Ontario, and rivers flowing into bay (Agricultural — Recreational Area 3) Type of Sediment Number of Samples Analyzed Content IN DRIED sediment, PPB ^ Location p,p'-DDE P.p-TDE o,p'- & p.p'- DDT = Total DDT Dieldrin 1 . River System - Moira River Organo-sand — mean —max — min 6 13.7 9.0 Trace 24.5 123.0 Trace 3.5 ND Trace 41.7 132.0 Trace 1.0 6.0 ND Napanee River Sandy-gravel — mean — max — min 7 3.1 11.0 Trace 8.4 27.0 Trace 1.1 ND Trace 12.6 38.0 Trace 0.1 1.0 Trace Salmon River Organo-sand — mean — max — min 6 13.0 36.0 2.0 12.8 36.0 1.0 5.2 9.0 3.0 31.0 81.0 6.0 1.5 7.0 Trace Trent River and Tributaries Organo-sand — mean — max — min 13 20.5 497.0 ND 95.2 1160.0 ND 16.8 109.0 ND 132.5 1766.0 ND 0.8 6.0 ND Total River System — mean 32 14.0 47.5 8.7 70.2 0.8 2. Bay — Lake Ontario ' Bay of Quinte Organo-silt — mean — max — min 15 10.3 40.0 2.0 13.3 44.0 1.0 2.1 ND 2.0 25.7 84.0 5.0 0.5 2.0 ND Total River— Bay System —mean 47 12.8 36.6 6.6 56.0 0.7 ■ ND: not detected. - o,p'-DDT was present only in sediment from Trent River where o.p'-DDT was 1.5 and p,p'-DDT 15.3 ppm. ■' DDE:TDE:DDT ratio in river system was 2:6:1. « DDE:TDE:DDT ratio in bay was 5:6:1. TABLE 2D. — Residues of organochlorine insecticides in sediment from Muskoka Lake System (Recreational Area 4) Number of Content IN dried sediment, PPB ■ Type of Samples Location Sample Analyzed p.p'-DDE p.p'-TDE P.p'-DDT ■ Total DDT Dieldrin 1 . Lake System ' L. Muskoka Fine & coarse —mean 10 8 12 5 25 Trace sand — max 15 56 44 110 Trace —min 2 1 Trace 3 ND Clay silt — mean 19 108 114 28 250 Trace —max 1080 1430 370 2880 Trace — min 2 1 Trace 3 ND L. Rosseau Clay & sand silt —mean 5 91 112 16 219 ND — max 190 140 27 357 ND —min 10 30 2 42 ND L. Joseph Clay & sand silt — mean 5 35 64 5 105 ND —max 130 230 25 385 ND — min 13 ND ND 13 ND Total Lake System — mean 39 71 81 18 170 2. River Outlet * Moon R. Clay & sand silt —mean 3 87 20 3 110 ND — max 150 30 5 185 ND —min Trace ND ND Trace ND N. Muskoka R. Coarse sand — mean 2 ND ND ND ND ND Total Lake and — mean 44 68 73 16 157 ND River System ND: not detected. ■ o.p'-DDT not detected or in trace amounts. ■ ratio of DDE:TDE:DDT in lake system 8:9:2. ratio of DDE:TDE:DDT in river outlet 27:7:1. Muskoka there was a distinct difference in residue be- tween sand and silt sediments. In 10 sandy sediments there was a mean residue of 25 ppb SDDT as opposed to 250 ppm for 19 silt sediments. In a traverse from shallow to deep water in the southern part of Lake Muskoka there were only slight differences in residues of sediments sampled at three depths. Sediments in the top inch contained 80 to 91 ppb 2DDT; in the second inch the range was 13 to 36 ppb, and in the 2-4-inch depth it was 3 to 1 3 ppb. Residues were higher in the shallow water and declined only slightly in moderate and deep water. The North Muskoka River which runs into the Muskoka Lakes had a coarse sand sediment in which DDT could not be detected. On the other hand, the Moon River which drains the three Muskoka Lakes into Georgian Bay, Lake Huron, had clay or silt sediments that con- tained a mean residue of 110 ppb 2DDT. This river is also developed for recreation and, like the lakes, is surrounded by land that had been treated with DDT up to 1966. Since the amount of sediment moving down this river — lake system is considered very small, the largest quantity of DDT moving out of the area would be expected to be soluble. Movement of sediments later- 170 Pesticides Monitoring Journal ally from shallow to deep water would be predicted to occur, but this would not remove residues from the system. The ratio of DDE;TDE:DDT in the whole system in- dicated very low levels of the parent compound but higher residues of DDE and DDD. In the lakes this ratio was 8:9:2; in the outlet river the metabolite DDE in- creased to a ratio of 29:7:1 (Table 2D). Both ratios in- dicated considerably more breakdown of parent DDT to its metabolites than in any other system. Dieldrin and o,p'-DDT were virtually absent from the sediments of this system. FISH SPECIES A total of 1,926 sample analyses were conducted on 2,540 fish of 38 different species. In the four study areas: one agricultural, two agricultural — recreational, one recreational, there were multiple species of fish caught: 22, 20, 26, and 15, respectively. These species varied from low-fat benthic invertebrate and plankton feeders (less than 4'% ) to high-fat piscivores (over 1%). In each area certain species were caught predominantly in the lakes; other species were caught predominantly in rivers and streams. The following eight species were confined mainly to lake environments. 1. Alewife (Alosa pseudoharengus) 2. Burbot (Lota lota) 3. Cisco (Coregonus artedii) 4. Coho salmon (Oncorhynchus kisutch) 5. American smelt (Osmenis mordax) 6. Freshwater drum (Aplodinotus grunniens) 7. Lake Trout (SaheJimis namaycush) 8. Lake whitefish (Coregonus cliipeaformis) The following six species were caught mainly in tlie river environment: 1 . Creek chub (Semotiltis atromacidatus) 2. Blacknose dace (Rhinkhthys atratidus) 3. Mooneye (Hiodon lergistis) 4. Brook trout (Sahelinus foniinalis) 5. Brown trout (Salmo triitta) 6. Rainbow trout (Salmo gairdneri) All other species Vvere caught in both rivers and lakes of one or more of the study areas. The analysis data for both DDT and dieldrin are pre- sented as tissue concentrations in the edible portion, as concentration in the extractable fat, and as total body loads of the whole fish (Tables 3, 4, 5). Body loads are calculated from eviscerated fish con- centrations and total body weights and are presented primarily for intraspecies comparison of residue ac- cumulation with increasing size of fish. They cannot be combined as gross quantities of insecticide since the viscera may have concentrations quite diiTerent from muscle, nor should they be used for interspecies com- parison because muscle weight to body weight ratios vary considerably between species. However, they can be used as a rough index of interspecies differences in pesticide accumulation which may reflect dietary pref- erences and habitat. DDT— EDIBLE TISSUE CONCENTRATIONS In only two study areas (areas 1, 3) were fish species found with mean 2DDT levels below 0.1 ppm (Tables 3, 4). Of these, rockbass (AmblopUtes rupeslris), blue- gill (Lepomis macrochirus), and brown bullhead (Ictahirus nehidosus) were common to both areas, whereas yellow perch (Perca flavescens), green sunfish {Lepomis cyaneUus). and freshwater drum were pres- ent only in area 1, and pumpkinseed {Lepomis gih- hosus) was present only in area 3. Most were of low fat content (less than 2%) and most belonged to the family Cypriniformes. Freshwater drum with a high fat content (7.3%) contained only 0.03 ppm 2DDT and were caught in the outer bay at Long Point, Lake Erie. More than half the species from all study areas con- tained residues of -DDT between 0.1 and LO ppm. These included the majority of the low-, medium-, and high-fat plankton feeders, the low- to medium-fat bottom feeders, and the low-fat piscivores. Alewives from area 1 and blacknose dace and emerald shiners (Notropis atherinoides) from area 2 were present in this group, all with quite high fat content and low residues. Most of the bottom feeders were of low fat content (1-3%) and had mean residues between 0.1 and 0.3 ppm 2DDT, although individual brown bullhead and channel catfish {/cialurus punctatus) had residues up to 0.7 ppm. Those piscivores which had residues between 0.1 and 1 .0 ppm were largely low-fat species which devoured other low-fat species. These included northern pike {Esox Indus) and muskellunge (Esox masquinongy) from area 3, and burbot from all areas. These three fish spe- cies contained residues between 0.4 and 0.6 ppm 2DDT and were from 1.0 to 2.9% fat. Walleye (Stizostedion viireum vitreum ) from area 3 also fell into this cate- gory; however, they averaged only 500 g and contained 1.2% fat and 0.3 ppm 2DDT. About 30% of the fish species had residues of 2DDT between 1.0 and 10 ppm in the edible tissues. Included in this group were the high-fat bottom and plankton feeders and the medium-fat piscivores. In general, the benthos feeders had fat contents over 4% and con- tained less than 4 ppm 2DDT. Plankton feeders with these high residues tended to have higher contents of fat and slightly lower 2DDT residues. Alewives (area 1) and smelt in all areas fell into this group. Many of the low- to medium-fat piscivores had residues between 1.5 and 4 ppm SDDT. Largemouth bass (Micropterus salmoides), coho salmon, and brook, brown, and rain- bow trout fell into this category. Vol. 7, No. 3/4, March 1974 171 TABLE 3. — Fish species caught in 1968-71 in four study areas. 1 : tobacco belt and Long Point Bay; 2: Holland — Schomberg Rivers and Lake Simcoe: 3: Bay of Quinte and its river system: 4: Muskoka Lake System Area Number of Fish Analyzed ^ Average Weight, G Fat, % Content N EDIBLE TISSUE, PPM = Species p,p'-DDE p,p'-TDE p,p'-DDT Total DDT DIELDRIN Clupeiformes Clupeidae Alewife (Alosa pseudoharengus) 3 8 10 102 53 23.0 15.6 0.25 0.64 ND 0.16 ND 0.53 0.25 1.33 ND 0.042 Shad, Gizzard (Dorosoma cepedianum) 3 II 310 3.3 0.184 0.148 0.094 0.426 0.009 Cypriniformes Catostomidae Redhorse, Norlhern (Moxostoma macro- lepidotum) 1 3 3 16 742 1,151 1.52 2.00 0.062 0.124 0.037 0.070 0.063 0.104 0.162 0.298 0.009 0.004 Sucker, Longnose (Catostomus catostomus) 4 7 454 2.14 0.075 0.024 0.122 0.221 0.005 Sucker, White (Catostomus commersoni) Cyprinidae Carp (Cyprinus carpio) 1 2 3 4 1 8 75 55 107 2 196 456 581 649 1,519 1.02 2.2 1.42 1.32 4.9 0.076 0.098 0.049 0.173 0.140 0.013 0.048 0.046 0.060 0.080 0.025 0.047 0.093 0.207 0.030 0.114 0.193 0.188 0.440 0.250 0.009 0.010 0.003 0.004 0.023 Chub, Creek (Seniotilus atromaculatus) 1 2 5 8 72 60 3.6 2.4 0.400 0.041 0.142 0.036 0.136 0.037 0.678 0.114 0.036 0.003 Dace, Blacknose (Rhinichthys atratulus) 1 2 16 28 2.2 1.9 4.8 6.1 0.82 0.094 0.15 0.033 0.10 0.058 1.07 0.185 0.080 Trace Shiners, Emerald f Notropis atherinoides) 2 473 > 1.2 5.94 0.202 0.140 0.044 0.386 0.022 Shiners, Golden (Notemigonus crysoleucas) 2 182 ' 7.3 4.11 0.471 0.411 0.161 1.043 0.094 Shiners, Spottail (Notropis hudsonius) Gadiformes Gadidae 1 10 5.2 4.17 0.154 0.084 0.144 0.382 0.018 Burbot (Lota lota) 2 4 22 9 1,952 903 1.0 1.4 0.196 0.097 0.062 0.046 0.105 0.209 0.363 0.352 0.004 0.006 Osteoglossi formes Hiodontidae Mooneye (Hiodon tergisus) Perciformes Centrarchidae 3 6 242 3.3 0.079 0.033 0.039 0.151 0.007 Bass, Largemouth (Microplerus salmoides) 1 I 2 12 4 206 579 380 7.5 3.9 1.0 2.24 0.85 0.060 0.82 0.35 0.023 0.80 0.27 0.041 3.86 1.48 0.124 0.190 0.016 0.001 Bass, rock (Ambloplites rupestris) 1 2 3 4 15 21 38 70 139 130 157 175 1.8 2.4 1.0 0.8 0.073 0.142 0.017 0.096 0.015 0.069 0.010 0.034 0.014 0.088 0.012 0.121 0.102 0.299 0.039 0.251 0.005 0.012 0.002 0.005 Bass, Smallmouth (Microplerus dolomieui) 1 2 3 4 18 36 24 34 410 552 503 266 2.4 6.0 2.2 2.2 0.387 0.85 1.55 0.28 0.111 0.32 0.40 0.15 0.378 0.45 0.75 0.64 0.876 1.62 2.70 1.07 0.006 0.021 0.016 0.024 BluegiU (Lepomis macrochirus) 1 3 6 5 200 116 1.5 1.4 0.12 0.034 0.010 0.024 0.011 0.036 0.033 0.094 0.002 0.012 Crappie, Black (Pomoxis nigromaculatus) 1 3 7 23 97 169 1.4 1.2 0.056 0.071 0.041 0.052 0.036 0.063 0.133 0.186 0.015 0.001 Pumpkii^eed (Lepomis gibbosus) 1 3 4 12 27 47 8 94 51 108 84 3.1 2.9 1.4 1.9 0.133 0.175 0.014 0.166 0.077 0.221 0.008 0.037 0.088 0.189 0.010 0.139 0.298 0.585 0.032 0.342 0.015 0.023 0.001 0.006 Sunfish, Green (Lepomis cyanellus) Collidae 1 4 199 2.3 0.050 ND ND 0.050 ND Sculpin (Cotlus species) Percidae Perch, Yellow (Perca fiavescens) 2 1 2 3 4 22 14 48 62 36 7.5 122 171 154 131 4.2 1.6 2.4 1.2 0.8 0.022 0.057 0.279 0.082 0.143 0.044 0.010 0.097 0.040 0.045 0.040 0.020 0.119 0.072 0.188 0.106 0.087 0.495 0.194 0.376 0.004 0.002 0.015 0.001 0.005 Walleye (Stizostedion vitreum vitreum) Sciaenidae 2 3 4 33 72 49 2,706 500 1,437 5.3 1.4 2.0 0.87 0.109 0.80 0.24 0.53 0.23 0.61 0.108 1.43 1.72 0.270 2.46 0.022 0.003 0.010 Drum, Freshwater (Aplodinolus grunniens) 1 10 239 7.3 0.033 ND ND 0.033 ND 172 Pesticides Monitoring Journal TABLE 3. — Fish species caught in 1968-71 in four study areas. I: tobacco belt and Long Point Bay: 2: Holland — Schomberg Rivers and Lake Siincoe: 3: Bay of Quinte and its river system; 4: Muskoka Lake System — Continued Area Number of Fish Analyzed i Average Weight, G Fat, % Content IN edible tissue, PPM = Specfes p.p'-DDE p,p'-TDE p,p'-DDr Total DDT DiELDRIN Serranidae Bass, While iRoccus cbrysops) 1 3 12 3 123 322 3.2 3.6 0.093 0.68 0.003 0.49 0.019 0.81 0.115 1.99 0.003 0.002 Perch, White (Roccus americanus) 3 22 194 4.0 0.254 0.127 0.151 0.532 0.022 Salmoniformes Esocidae Pike, Northern (Esox luciits) 2 3 14 69 993 1,468 2.9 1.2 0.307 0.284 0.104 0.142 0.157 0.171 0.568 0.597 0.006 0.002 Muskellunge (Esox masquinongy) 3 4 1 3 1.939 2,686 2.4 2.4 0.304 0.935 0.115 0.244 0.166 1.323 0.585 2.502 0.007 0.005 Osmeridae Smelt, American (Osmerus mordax) 1 2 3 4 13 10 7 147 25 48 36 24 2.2 7.1 8.6 5.8 0.039 0.62 1.28 0.67 0.038 0.23 0.75 0.25 0.087 0.27 1.20 0.95 0.164 1.12 3.23 1.87 0.011 0.027 0.043 0.020 Salmoiiidae Cisco (Coregonus artedii) 2 3 4 9 5 6 101 460 453 11.2 8.0 5.2 0.32 0.64 1.03 0.29 0.39 0.53 0.67 0,80 2.68 1.28 1.83 4.24 0.046 0.023 0.014 Salmon, Coho (Oncorhychus kisutch) 1 3 5 4 1,637 1,068 9.2 7.1 1.16 1.22 0.40 0.26 0.45 0.71 2.01 2.19 0.008 0.064 Trout, Brook (Salvelinus fontinalis) 3 4 1 3 400 121 5.37 2.45 1.11 0.109 0.101 0.027 0.132 0.082 1.343 0.218 0.033 0.010 Trout, Lake (Salvelinus namaycush) 2 3 4 21 223 4,318 286 2,899 10.2 3.59 10.0 6.32 0.632 6.77 2.05 0.505 2.01 4.07 0.182 13.63 12.44 1.319 22.41 0.162 0.026 0.095 Trout, Brown (Salmo Irutta) 1 3 6 2 122 824 4.77 5.28 0.94 1.83 0.15 0.91 0.38 0.28 1.47 3.02 0.047 0.001 Trout, Rainbow (Salmo gairdneri) I 9 1,757 5.14 0.76 0.21 0.25 1.22 0.068 Whitefish, Lake (Coregonus clupeaformis) 2 3 4 21 4 21 687 1,549 1,632 4.3 15.3 5.6 0.48 0.88 3.08 0.27 0.68 1.52 0.74 0.88 8.34 1.49 2.44 12.94 0.004 0.254 0.054 Siluriformes Ictaluridae Bullhead, Brown (Ictalurus nebutosus) 1 2 3 4 6 5 33 13 169 100 256 280 1.6 2.4 1.8 1.7 0.026 0.280 0.051 0.296 0.015 0.170 0.019 0.092 0.013 0.059 0.025 0.187 0.054 0.515 0.095 0.575 0.002 0.047 0.002 0.005 Catfish, Channel (Ictalurus punctatus) 2 3 20 2 118 2,515 2.9 12.7 0.095 0.310 0.080 0.233 0.036 0.127 0.211 0.680 0.004 0.027 ^ Analyzed in 20-sampIe analyses for each species. ' The overall ratios of DDE:TDE:DDT in fish were Area 1 5;2:3 Area 2 9:5;6 Area 3 4:2:3 Area 4 6:2:9 Only two fish species contained residues over 10 ppm. These were lake trout, a piscivore caught in areas 2 and 4, and lake whitefish, a benthic invertebrate feeder caught in area 4. The lake trout contained about 10% fat and carried the highest residues of any fish: 12.4 ppm in area 2 and 22.4 ppm in area 4. Very high resi- dues (12.9) in lake whitefish were recorded only from area 4; weight of these fish averaged 1600 g. The tissues of fish caught in the Muskoka Lakes had the highest residues of 2DDT of all four areas; however, the average weight of fish from those lakes was greater than the average weight of fish from other waters. Data support the finding that a buildup of concentration in 2DDT residues is related to increased fat content, which in itself reflects the feeding habits. The ratio of DDE:TDE:DDT varied considerably be- tween species and between locations; however, the gen- eral averages for all fish for areas 1, 2, and 3 were very similar. These ratios were approximately 5:2:3 in area 1, 9:5:6 in area 2, and 4:2:3 in area 3. Area 4 showed considerable difference from these; it had a ratio of 6:2:9, indicating a greater percentage of the parent compound and less breakdown to the two metabolites. These differences were reflected in most fish species to varying degrees. Of all species from the four areas, brown bullhead had the least variation in residue ratios. DIELDRIN CONCENTRATIONS IN EDIBLE TISSUE If the tissue residues of dieldrin are grouped into those fish containing (a) up to 0.010, (b) 0.011 to 0.100, and (c) over 0.101 ppm, then species are about equally divided into the first and second categories (Tables 3, 4). Vol. 7, No. 3/4, March 1974 173 TABLE 4. — Fish species categorized 1968-71 according to level of total DDT and dieldrin in four study areas. 1 : tobacco bell & Long Point Bay; 2: Holland — Schomberg Rivers & Lake Simcoe; 3: Bay of Qiiinte and its river system; 4; Miiskoka Lake System Residue in Residue in Edible Edible Study Portion, Study Portion. Area Insecticide PPM Species Area Insecticide PPM Species 1 DDT, TDE. 0.00-0.10 Bass R.. Bluegill, Bullhead B., 1 Dieldrin 0,000-0.010 Alewife, Bass S. Bass S.M., DDE 0.11-1.0 Perch Y., Sheepshead, and Sunfish G. Alewife, Bass S.M., Bass W., Carp, Chub C, Crappie B., Pumpkinseed, Redhorse N., Shiners S., Smells A., and Sucker W. 0.011-0.100 Bass W., Bluegill, Bullhead B., Perch Y., Redhorse N., Salmon C, Sheepshead, Sucker W., and Sunfish G. Carp, Chub C, Crappie B., Dace B., Pumpkinseed, Shiners S., Smelts A., Trout 2 1.1-10 0.11-1.0 1.1-10 over 10 Bass L.M., Dace B., Salmon C, Trout Brown, and Trout R. Bass R., Bullhead B., Burbot, Catfish C, Chub C, Dace B., Perch Y., Pike N,, Pumpkinseed, Sculpin, Shin- ers E., Shiners G.. and Sucker W. Bass L.M , Bass S.M., Cisco, Smelts A., Walleye, and Whitefish L. Trout L. 2 over 0.101 O.OOO-O.OIO 0.011-0.100 Brook, Trout Brown, and Trout R. Bass L.M. Burbot, Catfish C, Chub C, Dace B., Pike N., Sculpin, Sucker W., and Whitefish L. Bass L.M., Bass R., Bass S.M.. BuUhead B., Cisco, Perch Y.. Pumpkinseed, Shiners E.. Shiners G., Smelts A., and Walleye. 3 0.00-0.10 0.11-1.0 1.1-10 Bass R., Bluegill, Bullhead B., and Pumpkinseed. Bass L.M., Catfish C. Crap- pie B., Mooneye, Muskel- lunge. Perch W.. Perch Y., Pike N., Redhorse N., Shad G.. Sucker W., and Wall- eye. Alewife, Bass S.M., Bass W., Cisco, Salmon C, Smelts A., Trout Brook, Trout Brown, Trout L., and White- fish L. 3 over 0.101 0.000-0,010 0,011-0.100 Trout L. Bass L.M., Bass R., Bass W., Bullhead B., Crappie B., Mooneye, Muskellunge, Perch Y., Pike N., Pump- kinseed, Redhorse N., Shad G., Sucker W., Trout Brook, Trout Brown, and Walleye. Alewife, Bass S.M., Bluegill. Catfish C, Cisco, Perch W., Salmon C. Smelts A., and Trout L. 4 0.11-1.0 1,1-10 over 10 Bass R., Bullhead B., Burbot, Perch Y., Pumpkinseed, Sucker L.N., Sucker W., and Trout Brook. Bass S.M., Cisco, Muskel- lunge. Smelts A., and Wall- eye. Trout L., and Whitefish L. 4 over 0.101 0.000-0,010 0,011-0,100 Whitefish L. Bass R., Bullhead B., Burbot, Muskellunge, Perch Y.. Pumpkinseed, Sucker L.N., Sucker W., Trout Brook and Walleye. Bass S.M.. Cisco, Smelts A., Trout L., and Whitefish L. TABLE 5. — Accumulations of DDT and its metabolites and dieldrin in several fish species by weight class at four study areas Study Weight Class, Number of Fish Average Weight, DDT and Metabolites in Dieldrin in ' Tissue, Fat, Fish, Tissue, Fat, Fish. Species Area G Analyzed G PPM PPM MO PPM PPM flC Cypriniformes Catostomidae Sucker, White 1 0- 300 7 124 0.12 15.1 15,0 0.007 0.89 1.60 {Catostomus 601- 900 1 699 0.08 2.4 55.9 ND — ND commersoni) 2 0- 300 29 99 0.13 5.8 12.2 0.018 0.80 0.98 301- 600 20 480 0.16 7.1 77.3 0.004 0.17 1.45 601- 900 20 767 0.30 16.0 223.0 0.005 0.27 3,69 901-1200 6 1,028 0.26 11.0 268.0 0.004 0.17 4.62 over 1201 1 1,239 0.35 29.4 434.0 0.005 0.42 6.20 3 0- 300 8 205 0.17 22,9 32.5 0.005 0.68 0.96 301- 600 22 449 0.12 9.6 56.0 0.002 0.16 1.10 601- 900 16 723 0.16 8.4 108.0 0.003 0.16 2.39 901-1200 7 1,033 0.38 22.5 408.0 0.001 0.06 0.81 over 1201 2 1,337 0.66 45.9 877.0 ND — — 4 0- 300 20 225 0,09 13.7 17.1 0.002 0.32 0.56 301- 600 27 428 0.15 13.5 70.0 0.004 0.35 1.59 601- 900 20 746 0.98 52.9 743.0 0.004 0.22 3.20 901-1200 30 1,022 0.55 37.7 560.0 0.006 0.41 5.64 over 1201 10 1,349 0.50 29.5 658.0 0.007 0.42 8.82 Cyprinidae Shiners. Golden 2 0- 10 157 3.9 1.13 27.8 2.75 0.098 2.42 0.30 (Notemigonus 11- 20 17 12.0 0.69 13.7 8.24 0.065 1.28 0.77 crysoleucas) 21- 40 5 28.0 0.26 5.9 7.15 0.111 2.55 3.08 over 101 3 109.0 0.04 4.5 4,64 0.035 3.64 3.85 174 Pesticides Monitoring Journal TABLE 5. — Accumulations of DDT and its metabolites and dieldrin in several fish species by weight class at four study areas — Continued Study Weight Class, Number of Fish Average Weight. DDT and Metabolites in Dieldrin in ' Tissue, Fat, Fish, Tissue, Fat, Fish, Species Area G Analyzed G PPM PPM na PPM PPM no Gadiformes Gadidae Burbot 2 0-1000 4 713 0.46 44.0 209.0 0.011 1.06 5.4 (Lota tola) 1001-2000 7 1,469 0.32 25.3 449.0 0.005 0.40 7.4 2001-3000 9 2,565 0.36 47.1 454.0 0.006 0.78 14.4 over 3001 2 3,363 0.32 59.4 1,063.0 0.005 0.94 16.8 4 0-1000 7 769 0.34 21.2 264.0 0.005 0.31 3.6 1001-2000 2 1,374 0.39 70.2 503.0 0.008 1.43 10.8 Percljormes Cenlrarchidae Bass, Largemouth 1 0- 300 2 153 3.86 51.5 740.0 0.190 4.92 34.9 (Micropterus 2 0- 300 5 206 0.95 25.4 201.0 0.005 0.13 1.04 satmoides) 301- 600 1 343 1.23 47.3 422.0 0.005 0.19 1.72 601- 900 4 760 1.75 40.7 1,359.0 0.006 0.14 4.55 over 901 2 1,264 2.36 62.9 2,603.0 0.067 1.79 103.0 3 0- 300 2 245 0.02 1.8 4.8 0.001 0.09 0.20 301- 600 2 515 0.23 25.5 119.0 ND — — Bass, Rock (Ambloptites rupestris) 1 0- 100 7 79 0.18 8.3 12.7 0.016 0.73 1.02 101- 200 8 149 0.47 17.8 62.2 0.016 0.61 1.79 2 0- 100 6 60 0.28 9.1 16.2 0.022 0.72 1.68 101- 200 13 145 0.30 13.6 37.3 0.008 0.36 1.11 201- 300 2 248 0.21 13.1 49.2 0.007 0.43 1.95 3 0- 100 6 77 0.04 2.8 2.9 0.002 0.16 0.14 101 200 27 160 0.03 3.3 5.5 0.003 029 0.41 201- 300 5 239 0.07 10.5 16.6 0.002 0.30 0.30 4 0- 100 13 81 0.32 23.4 26.4 0.004 0.29 0.35 101- 200 37 135 0.22 27.2 30.4 0.004 0.49 0.54 201- 300 11 243 0.24 57.8 56.1 0.005 1.22 1.24 over 301 9 390 0.27 52.5 110.0 0.007 1.35 2.76 Bass, Smallmouth (Micropterus dotomieui) I 151- 300 10 213 0.51 32.9 109.0 0.004 0.26 0.75 301- 450 4 352 0.88 47.5 310.0 0.006 0.32 2.11 451- 600 2 469 2.41 81.7 1,113.0 0.020 0.68 9.02 over 601 2 1,449 1.20 16.0 1,776.0 0.005 0.07 7.25 2 0- 150 12 78 1.14 38.3 97.0 0.035 1.17 0.70 151- 300 5 221 1.21 21.9 265.0 0.027 0.49 6.02 301- 450 8 362 1.14 16.2 414.0 0.015 0.21 4.97 451- 600 7 533 1.69 28.9 898.0 0.012 0.21 6.34 over 601 12 959 1.86 29.9 1,761.0 0.013 0.21 11.76 3 0- 150 4 101 0.13 7.8 11.0 0.003 0.18 0.38 151- 300 4 229 0.10 6.5 25.0 0.001 0.06 0.33 301- 450 7 344 0,22 13.1 77.0 0.002 0.12 0.76 451- 600 3 525 0.33 25.2 115.0 0.003 0.23 1.73 over 601 6 1,164 10.6 255.0 12,205.0 0.055 1.33 76.4 4 0- 150 16 108 0.50 18.9 59.0 0.008 0.31 0.89 151- 300 9 192 0.76 41.6 138.0 0.005 0.27 0.83 451- 600 6 512 0.95 54.6 462.0 0.016 0.92 8.59 over 601 3 834 4.43 258.0 5,507.0 0.181 1.05 164.0 Crappie, Black (Pomoxis nigromaciilatus) 1 0- 150 6 84 0.13 8.4 11.1 0.017 1.12 1.04 151- 300 1 173 0.17 17.9 29.4 0.006 0.63 1.04 3 0- 150 15 106 0.10 12.0 8.30 0.002 0.25 0.09 151- 300 4 204 0.03 3.1 6.21 0.002 0.20 0.43 301- 450 4 371 0.65 21.3 272.0 — — — Pumpkinseed (Lepomis gibbosus) 1 0- 50 3 33 1.28 27.0 39.0 0.033 0.70 4.85 51- 100 4 81 0.08 3.1 6.0 0.017 0.68 1.33 101- 150 4 117 0.05 1.6 5.7 0.004 0.14 0.42 151- 200 I 174 0.05 2.2 8.7 Trace 0.02 0.07 2 0- 50 13 29 0.94 28.8 27.0 0.036 1.10 0.94 51- 100 13 67 0.21 8.1 14.9 0.010 0.39 0.66 101- 150 1 107 0.76 30.6 81.0 0.010 0.40 1.09 3 0- 50 2 20 0.07 2.7 1.2 0.001 0.04 0.01 51- 100 11 90 0.03 2.5 1.9 0.001 0.08 0.08 101- 150 33 118 0.03 2.4 3.3 0.001 O.08 0.12 151- 200 1 156 0.04 2.1 6.4 0.006 0.03 0.94 4 0- 50 2 47 0.24 26.8 11.5 0.013 1.43 0.61 51- 100 2 61 0.28 14.1 16.2 0.006 0.30 0.34 101- 150 4 113 0.42 17.5 47.9 0.008 0.33 0.87 Vol. 7, No. 3/4, March 1974 175 TABLE 5. — Accumulations of DDT and its metabolites and dieldrin in several fish species by weight class at four study areas — Continued Study Weight Class. Number of Fish Average Weight. DDT AND Metabolites in Dieldrin in 1 Tissue, Fat, Fish, Tissue. Fat, Fish, Species Akea G Analyzed G PPM PPM IIG PPM PPM JBO Percidae Perch. Yellow 1 0- 100 2 89 0.05 3.9 4.8 0.005 0.43 0.40 (Perca fiavescens) 101- 200 12 125 0.09 5.6 11.5 0.002 0.12 0.22 2 0- 100 11 59 0.52 21.1 22.4 0.042 1.71 1.35 101- 200 23 137 0.41 18.0 54.6 0.006 0.26 0.83 201- 300 5 251 0.42 15.4 99.7 0.008 0.30 1.91 over 301 9 364 0.66 23.1 239.0 0.009 0.31 3.41 3 0- 100 13 60 0.14 12.0 8.8 0.001 0.09 0.10 101- 200 36 148 0.20 16.8 30.8 0.002 0.17 0.22 201- 300 12 254 0.25 22.4 60.5 0.001 0.09 0.15 over 301 1 372 0.14 9.2 52.8 Trace 0.03 0.04 4 0- 100 11 84 0.21 26.6 17.2 0.003 0.38 0.21 101- 200 23 139 0.38 50.0 54.0 0.005 0.66 0.77 201- 300 1 230 0.87 74.2 200.0 0.009 0.77 2.07 over 301 1 360 1.69 235.0 608.0 0.017 2.36 6.12 WaUeye (Stizostedion 2 0-1000 9 605 0.32 6.8 209.0 0.016 0.34 9.0 vitreum vilreum) 1001-2000 7 1,476 0.68 11.2 994.0 0.019 0.31 28.0 2001-3000 5 2.386 4.03 64.5 9,860.0 0.025 0.40 59.1 3001-4000 5 3,529 2.59 51.9 8,993.0 0.025 0.50 86.0 over 4001 7 6,280 2.04 43.7 13,290.0 0.026 0.56 154.0 3 0-1000 65 418 0.24 18.3 104.0 0.003 0.23 1.3 1001-2000 6 1,206 0.20 9.7 240.0 0.004 0.19 4.8 2001-3000 1 2,300 2.77 112.0 6,371.0 0.001 0.04 2.3 4 0-1000 26 332 0.80 72.9 352.0 0.007 0.64 3.3 1001-2000 10 1,409 2.32 104.0 3,012.0 0.014 0.63 18.5 2001-3000 5 2,424 3.01 124.0 5,743.0 0.018 0.74 45.3 3001-4000 3 3,337 3.05 98.4 10,140.0 0.026 0.83 93.6 over 4001 5 4.902 10.4 193.0 50,140.0 0.030 0.56 144.0 Serranidae Perch. White 3 0- 150 7 116 0.36 8.6 55.6 0.028 0.68 3.12 (Roccus 151- 300 13 204 0.66 15.3 131.0 0.024 0.56 4.40 americanus) 301- 450 2 397 0.35 27.3 136.0 0.001 0.08 0.40 Salmoniformes Esocidae Pike, Northern 2 0-1000 2 625 0.09 5.8 68.0 0.002 0.14 0.61 (Esox luciiis) 1001-2000 9 1.566 0.45 14.5 702.0 0.006 0.19 7.81 2001-3000 1 2.782 0.850 26.6 2,365.0 0.010 0.31 2.8 over 3001 2 4,887 1.43 51.1 6,932.0 0.008 0.29 38.0 3 0-1000 25 569 0.22 28.6 125.0 0.001 0.13 0.38 1001-2000 30 1,467 0.75 50.1 1,122.0 0.004 0.27 4.91 2001-3000 7 2,286 0.73 52.9 1,723.0 0.001 0.07 3.19 over 3001 7 3,869 0.86 63.5 3.910.0 0.005 0.37 21.0 Osmeridae Smelt. American 1 0- 20 4 16 0.13 7.4 2.0 0.009 0.52 0.14 (Osmerus mordax) 21- 40 9 28 0.19 8.0 5.3 0.013 0.55 0.34 2 21- 40 4 30 0.61 11.3 18.4 0.015 0.28 0.46 41- 60 2 50 1.79 19.5 92.7 0.050 0.54 2.41 61- 80 4 66 1.29 15.5 846.0 0.033 0.40 1.80 3 0- 20 1 16 2.14 23.7 33.6 0.062 0.69 0.97 21- 40 4 31 2.81 34.6 85.1 0.040 0.49 1.27 41- 60 2 54 4.62 57.3 243.0 0.041 0.51 2.26 4 0- 20 113 17 2.00 29.5 34.2 0.023 0.34 0.39 21- 40 25 25 1.69 32.6 43.8 0.025 0.48 0.64 41- 60 6 54 1.19 38.6 51.7 0.008 0.27 0.44 61- 80 3 66 1.23 37.6 82.3 0.013 0.40 0.89 Salmonidae Cisco 2 0- 200 9 101 0.13 1.2 130.0 0.046 0.41 4.6 (Coregonus artedii) 3 201- 400 2 327 0.48 9.7 152.0 0.015 0.30 4.9 401- 600 3 548 1.02 10.3 562.0 0.028 0.28 15.5 4 201- 400 17 314 3.43 52.9 1,074.0 0.015 0.24 4.9 401- 600 39 485 4.27 63.4 2,126.0 0.014 0.21 6.7 over 601 5 730 6.21 107.0 4,543.0 0.028 0.48 21.1 Trout. Lake & Brook (Salvelinus namay- 2 0-2000 2 1,252 4.61 50.0 7,371.0 0.095 1.03 158.0 cush & Salvelinus 2001-4000 7 3,230 11.1 112.0 35,520.0 0.147 1.48 460.0 fontinalis) 4001-6000 7 4,570 17.6 174,0 83.420.0 0.203 2.01 908.0 6001-8000 4 6,562 9.72 S5.0 62.700.0 0.158 1.38 1 .034.0 3 0-2000 2 2 343 1.3 30.0 457.0 0.030 0.67 10.1 4 0-2000 67 3 761 15.3 282.0 9,394.0 0.034 0.63 53.0 2001-4000 108 2,785 24.1 211.0 67,570.0 0.109 0.79 333.0 4001-6000 32 4,605 29.2 228.0 139.200.0 0.108 0.84 506.0 6001-8000 12 6,644 40.5 413.0 272.300.0 0.109 l.ll 733.0 over 8001 8 8,731 65.8 419.0 570,600.0 0.228 1.53 1,994.0 176 Pesticides Monitoring Journal TABLE 5. Accumulations of DDT and its metabolites and dieldiin in several fish species by weight class at four study areas — Continued Study Weight Class, Number of Fish Average Weight, DDT AND Metabolites in DiELDRIN IN 1 Tissue, Fat, Fish, Tissue, Fat, Fish, Species Area c Analyzed G PPM PPM MO PPM PPM no Trout, Brown & Rainbow (Salmo trtttla & 1 0-1000 10 182 1.45 31.4 192.0 0.048 1.04 6.7 Salmo gairdneri) 1001-2000 2 1,415 1.08 18.1 1,518.0 0.100 1.68 137.0 2001-3000 2 2,750 1.03 18.3 2,828.0 0.070 1.24 193.0 over 3001 1 6,400 1.35 25.1 8,640.0 0.070 1.30 448.0 3 0-1000 2 824 3.02 57.2 226.0 0.001 0.02 0.8 Whitefish, Lake 2 0- 700 10 493 0.87 23.1 486.0 0.008 0.21 4.0 (Coregonus 701-1400 11 762 2.18 44.9 2,000.0 0.006 0.12 4.8 clupeaformis) 3 701-1400 3 1,238 2.36 14.8 2,921.0 0.274 1.72 341.0 over 2101 1 2,483 2.68 20.2 6,662.0 0.193 1.45 479.0 4 0- 700 3 566 9.49 348.0 5,758.0 0.044 1.61 23.9 701-1400 5 1,108 16.6 327.0 17,460.0 0.050 0.98 61.6 1401-2100 6 1,636 16.3 260.0 18,780.0 0.069 1.10 99.3 over 2101 7 2,460 12.1 185.0 31,730.0 0.044 0.67 119.0 Siluriformes Ictaluridae Bullhead, Brown 1 0- 150 1 95.0 0.10 7.9 0.9 0.004 0.33 0.04 (Ictalurus nebulosus) 151-300 3 167.0 0.03 2.9 5.9 0.002 0.18 0.35 301- 450 2 360.0 0.07 2.1 23.2 Trace 0.02 0.14 2 0- 150 3 47.0 0.37 11.7 13.9 0.059 1.86 2.27 151- 300 2 179.0 0.71 59.4 132.0 0.030 2.50 5.46 3 0- 150 4 114.0 0.06 2.3 6.5 0.004 0.15 0.31 151- 300 16 216.0 0.04 2.2 8.2 0.002 0.11 0.46 301- 450 13 349.0 0.17 10.5 64.2 0.001 0.06 0.36 4 0- 150 2 114.0 0.48 73.7 54.6 0.007 1.08 0.80 151- 300 7 227.0 0.34 19.1 77.4 0.004 0.22 0.90 301- 450 2 341.0 0.85 35.7 290.0 0.008 0.34 2.90 over 451 2 568.0 1.21 68.8 704.0 0.005 0.28 3.16 Catfish, Channel (Ictalurus punctatus) 2 0- 100 9 90 0.18 6.9 15.9 0.003 0.11 0.31 101- 200 10 133 0.23 7.3 32.5 0.008 0.26 0.68 201- 300 1 233 0.33 10.5 76.0 0.002 0.06 0.47 ND: not detected. One brook & one lake trout. Three brook & 64 lake trout. Fish with residues below 0.010 ppm were mainly bottom feeders or plankton feeders; there were also a few low-fat piscivores such as pike, muskellunge, and walleye. In areas 3 and 4 the majority of fish species fell into this low-fat category. The fish with tissue residues between 0.011 and 0.100 ppm dieldrin included fish with higher fat content, such as the benthic invertebrate, plankton feeders, and piscivores. The majority of the feeders had residues below 0.05; the piscivores trout and salmon were above this level. The majority of fish species caught in areas 1 and 2 had residues in this middle range. Only three species, one in each of the first three study areas, had residues over 0.1 ppm; these ranged from 0.19 to 0.26 ppm. The three species were largemouth bass in area 1, lake trout in area 2, and lake whitefish in area 3. DDT— WEIGHT CLASSES When fish species were divided into weight classes, a general trend of increasing tissue concentrations and increasing body loads of 2DDT could be correlated with the increasing body weights (Table 5). This increase was not consistent for all areas or all species, but the trend was evident. In some cases, however, increasing body weights were accompanied by decreasing tissue concentrations and either increasing body loads, e.g., pumpkinseed, or decreasing body loads, e.g., golden shiner {Noiemigoniis crysoleiicas). When each weight class was well represented, the increases in both tissue concentrations and body load were readily observed; this was very evident with the fatty piscivores. Lake trout exhibited the greatest accumulations of 2DDT. Among the centrarchids, pumpkinseed were placed in 50-g, rockbass in 100-g, smallmouth bass (Micropterus dolomieui) and black crappie (Pomoxis nigromaculatus) in 150-g, and largemouth bass in 300-g weight classes. In area 1 the lightest pumpkinseed had the highest body loads, tissue, and fat concentrations of 2DDT. Sub- sequent growth appears to have been more rapid than the accumulations of 2DDT; there was a noticeable decline in actual extractable fat from the smaller to the larger fish where this trend existed. In areas 2, 3, and 4 this species did exhibit a general increase in body burden of SDDT with increasing body weight. The heaviest class contained 81 /Ltg of 2DDT per 107 g of fish from area 2. Rock bass, smallmouth bass, and black crappie all ex- hibited little or no increase in tissue concentrations, slight increase in the extractable fat, and marked in- VoL. 7, No. 3/4, March 1974 177 crease in the body burden of 2DDT. The largest rock- bass (mean 390 g) contained 0.27 ppm in the tissue, 52.5 ppm in the fat, and 110 |Lig in the whole fish. The highest residues in smallmouth bass were from area 3 where fish with a mean weight of 1,164 g averaged 10.6 ppm SDDT in the tissue, 255 ppm in the fat, and 12 mg in the body. Largemouth bass contained increasing quantities of 2DDT in both tissues and in the total fish body. Fish weighing 1,264 g from area 2 contained 2.4 ppm in the tissue, 64 ppm in the fat, and 2.6 mg as a body load. Among the centrarchids, rockbass, black crappie, and pumpkinseed accumulated relatively low residues com- pared to the largemouth and smallmouth bass. These differences were probably related to feeding habits: the two species of bass become increasingly piscivorous and consume larger fish as they themselves increase in body weight, thus accumulating high residues. Among the bottom feeding catostomids and ictalurids. channel catfish was placed in 100-g. brown bullhead grouped in 150-g, and white sucker (Caiostomiis com- mersoni) in 300-g weight classes. The general trend in all three species was for slight increases of 2DDT in fat, tissue, and body burdens. Some inconsistencies oc- curred, but these were probably due to the inadequate sample size of the classes. The largest sample among these species was white sucker, and even when fish averaged 1.337 g in area 3, the body accumulation was only 0.9 mg 2DDT, much less than in the piscivorous centrarchids. Based on two of these three species, areas 3 and 4 appeared to have the greater accumulations of SDDT in fish tissue. Among the percids and serranids, yellow perch was placed in 100-g, white perch {Rocciis americamis) in 150-g, and walleye in 1-kg weight classes. Yellow perch, which was present in all four areas, exhibited the general trend of increasing 5!DDT concentrations in tissue, fat, and fish body with increasing body weight. The largest class, caught in area 4, weighed 360 g and contained 1.69 ppm 51DDT in the tissue, 235 ppm in fat, and 0.6 mg in the fish body. Residues in these perch indicated a greater accumulation in area 4 than in the other three areas. White perch were obtained in only one area but the same general trend was observed. Walleye were caught in three of the four study areas and in all cases the same trend of increasing tissue and fat concentration and body load occurred. The largest class weighed 4.9 kg and contained 10.4 ppm 2DDT in the tissue. 193 ppm in the fat, and had a body load of 50 mg per fish. The difference between perch and walleye was very obvious, based on size and JDDT accumulations. Burbot, a low-fat piscivore, was placed in a 1-kg weight class. It was present in areas similar to those nurturing walleye but failed to accumulate tissue residues or body loads to the same extent. A general increase did oc- cur with the increasing body weight, however. The low-fat northern pike showed a trend similar to walleye. Among these three piscivores accumulations may reflect the species of fish consumed, as all are voracious preda- tors and all are relatively low fat species. The smelt, a species related to the salmonids, was placed in a 20-g weight class. It showed a marked increase in tissue and fat concentrations and body loads as the body weight increased. Smelts averaging 66 g from area 2 accumulated up to 0.8 mg 2DDT per fish. Among the salmonids, the benthos feeders, cisco, and whitefish were placed in 200-g and 700-g weight classes; the predaceous trout were placed in 1-kg and 2-kg classes. In all classes a marked increase in tissue and fat concentrations and in body load of 2DDT occurred with increasing body weight. Among the ciscoes the largest fish weighed 730 g and accumulated 4.5 mg per fish in area 4; these showed greater accumulations of DDT than did ciscoes from area 3. Among the white- fish, the largest fish (2.5 kg) were found in area 4; these contained residues of almost 32 mg 2DDT per fish. This body burden was also greater than that for fish of similar size from area 3. Among fish of the lower weight classes, whitefish had greater accumula- tions than fish of similar size from area 2. Brown and rainbow trout from areas 1 and 3 weighing 6.4 kg accumulated up to 8.6 mg 2DDT. Lake trout, a fish that attained the greatest size and contained the highest fat level, exhibited the greatest increases in tissue and fat concentrations and showed the highest body burdens. Almost 0.6 g 2DDT was found in fish weighing 8.7 kg from area 4. These voracious predators were the peak of the food chain in areas 2 and 4. Compared to the smallest yellow perch and rockbass, they had up to 500 times as much 2!DDT in tissue and fat concentra- tions, and up to 1000 times as much in body burden. TISSUE, FAT. AND BODY LOADS— DIELDRIN Dieldrin residues were several magnitudes less than the SDDT. but nevertheless appeared to be present in all species. Tissue and fat concentrations were not readily correlated with body weight in most benthic invertebrate and plankton feeders but were more evident in the piscivores. Findings generally showed a correlation between in- creased tissue concentration and body loads with in- creased body weight; this was not marked in those fish of low fat content, but became more evident in high-fat bottom and plankton feeders and low-fat piscivores, and was most evident in the high-fat pis- civores. 178 Pesticides Monitoring Journal Viewed by study area, concentrations in fish tissue were greatest in area 4, even when similar weight classes were compared. Comparing weight classes, fish species in area 4 that had markedly elevated 2DDT residues were Cisco, lake whitefish, lake trout, and walleye, with slight increases in yellow perch and white suckers. In area 1, the fish species which exhibited slightly higher residues were rockbass and smallmouth bass. In area 2, pumpkin- seed and bullhead had residues that were slightly higher than in fish from other areas. In area 3, only smelts had residues that exceeded those in the other three areas. Since all weight classes are not fully represented, it is difficult to predict how weight classes would have com- pared at all levels. Discussion In spite of the fact that the volume of DDT and dieldrin used in the four study areas was quite different, residues in sediment from all four areas were similar. Character- istics of each area and placement of DDT and dieldrin probably had a marked effect on these findings. In areas 2, 3, and 4, DDT was used to control biting flies and was applied close to or over water, causing fairly direct contamination of both fish and sediments. Similar results of direct application have been observed in many bodies of water (10). In area 4 the contamination of water and sediment following use was facilitated by the absence of soil, or by the very thin cover of soil in the forested areas treated. In area 1, where DDT was used in large volume, a deep sandy loam soil likely prevented direct runoff into the aquatic environment, and trans- portation of DDT and dieldrin in this area by physical soil movement was probably greater than in any other area studied. The parent material o,p'-DDT was detected only in sediments where DDT had been used recently: namely, the tobacco belt, the rivers of area 2, and the Trent River of area 3. On the other hand, o,p' -DDT was absent where DDT had not been used for several years: namely, the lake in area 2, most of area 3, and area 4. The degradation pattern of DDT primarily to TDE and in lesser degree to DDE appeared similar in all four areas, in spite of the fact that DDT was still being used in areas 1. 2, and 3 during this study but had not been used since 1966 in area 4. These ratios were 22:78; 21:79; 12:88; and 10:90%, respectively. In areas 1 and 4 the ratio of the two metabolites DDE:TDE was 1:1, probably because sediments were more aerobic than those in areas 2 and 3 (1:3 and 1:4). This supposition is supported by studies of several authors (3, 5, 6), who demonstrated increased breakdown to DDE under aero- bic conditions. In areas 1, 2, and 3 DDT was applied up to and including the years of this sampling program; yet the actual level of residues in the sediments were lower than in area 4. It could be predicted from these data that residues will take much longer to disappear from area 4 than from areas 1, 2, and 3. This slow disappearance and/ or dispersion in the cooler, pre- cambrian lake environment is in keeping with the findings of Brown and Brown (16) in a subarctic en- vironment. Hindin et al. (7) reported traces of DDT in water coming from sediments in the ratio of 1:18,000. In a continuing study in preparation on area 1, the authors found a ratio of 1:2,400 between water and sediment for total DDT, and 1:2,700 for dieldrin. The difference between these two sets of data could be explained by differences in actual residues in the sediment and differences in the characteristics of the body of water. Nevertheless, sediments act as reservoirs of organo- chlorine insecticides which are constantly available for incorporation into tissues of bottom living organisms. Although two studies (8.9) have demonstrated that fish can remove 80 to 90% of the DDT from water by gills, a third study (17) has shown that 10 times more DDT was accumulated from the food chain than di- rectly from water during the period of observation. Sediment residues can therefore be either ingested directly by invertebrates or bottom feeders or indirectly by transfer through the water phase. In this study the ratio of metabolites to DDT in a pooled average of all fish by area was 7:3 in areas 1, 2, and 3. and 9:11 in area 4. The first three areas were almost identical and could be closely correlated with that ratio in the sediment; however, area 4 was distinctly different both with respect to fish and sediment. These differences may be related to the limnological char- acteristics of this deep, oligotrophic lake system which varies markedly from the shallow, eutrophic conditions prevalent in the other areas. Ratios of the metabolites DDE and TDE in fish from the four areas were 2:1 in areas 1, 2, and 3; and 3:1 in area 4. These ratios are almost the reverse of those found in sediments. Comparing the mean pesticide concentration by area, a multiplication factor from the lowest to the highest residue in fish ranged from 100 to 450. If weight class were taken into consideration, residue or magnification of the tissue from smallest to largest fish regardless of species varied from 130 to 530. If the body load of DDT in micrograms per fish is considered, an increase from the lowest to the highest ranged from 10^ to 33 x 10''. Dieldrin residues in tissue by a similar comparison rose by factors of 60 to 200. When weight class was included, the total accumulation per fish increased by multiples of 3 to 5 x 10''. The concentration of both DDT and dieldrin in sedi- ment (dry-weight basis) was about equivalent to the res- idue found in the tissue of the lowest fish species. The mean residues of SDDT in sediment and fish with the lowest tissue concentrations for the four areas were: area Vol. 7, No. 3/4, March 1974 179 1: (agricultural): 0.07 and 0.03 ppm; areas 2 and 3 (agricultural — recreational): 0.09 and 0.04 ppm, and 0.06 and 0.02 ppm, respectively; area 4 (recreational): 0.16 and 0.22 ppm. The relationships established in this study for 2DDT between sediment and fish, with further data on water, provided a ratio of sediment to water of 2,400:1; the ratio of sediment to low-fat fish was about 1:1. The ratio of lowest fish to highest fish was between 10^ and 10'', which gives a ratio of water to highest piscivores of 1:10^ or 10". A similar ratio could also be applied to the accumulation of dieldrin residues. A cknowledgment Many field staff members of the Ontario Ministry of Natural Resources and Ontario Ministry of Environ- ment are to be thanked for collecting and submitting samples from the four areas under study. Members of the Provincial Pesticide Residues Testing Laboratory are to be thanked for analyzing the large volume of material. LITERATURE CITED (/) Edwards, C. A. 1968. Insecticide residues in soil. Res- idue Reviews 13: 83-132. (2) Miles, J. R. W., and C. R. Harris. 1971. Insecticide resi- dues in a stream and a controlled drainage system in agricultural areas of southwestern Ontario. Pestic. Monit. J. 5; 289-294. {3) Miskus, R. P.. D. P. Blair, and J. C. Cesida. 1965. Con- version of DDT to DDD by bovine rumen fluid, lake water and reduced porphyrins. J. Ag. Food Chem. 13: 48L (.4) Ware. G. W., and C. C. Roan. 1970. Interaction of pesticides with aquatic microorganisms and plankton. Residue Reviews 33: 15-45. (5) Mendel, J. L.. and M. S. Walton. 1966. Conversion of p,p'-DDT to p,p'-DDD by intestinal flora of the rat. Science 151: 1527. ((5) Giienzi, W. D., and W. E. Beard. 1967. Anaerobic bio- degradation of DDT to DDD in soil. Science 156; 1116. (7) Hindin, £.. D. S. May. C. H. Dunstan. 1968. Collection and analysis of synthetic organic pesticides from surface and ground water. Residue Reviews 7: 130-156. (5) Holden. A. V. 1962. A study of the absorption of C"-labeled DDT from water by fish. Ann. Appl. Biol. 50: 467. (9) Marlli, E. H. 1965. Residues and some effects of chlori- nated hydrocarbon insecticides in biological material. Residue Reviews 9: 1-89. (.10) Johnson, D. W. 196S. Pesticides and Fish — A review of selected literature. Trans. Amer. Fish Soc. 97: 398- 424. (//) Eninger. M. B.. and D. 1. Mount. 1967. A wild fish should be safe. Environ. Sci. Technol. 1: 203-205. {12) Langlois, B. E., A. R. Stcmp, and B. J. Liska. 1964. Analysis of animal food products for chlorinated in- secticides. J. Milk Food Technol. 27: 202-204. 03) McCully. K. A., and W. P. McKinley. 1964. Determi- nation of chlorinated pesticide residues in fat by elec- tron capture gas chromatography. J. Ass. Offic. Agr. Chem. 42: 734-740. U4) Hamence, J. H., P. S. Hall, and D. J. Caverly. 1965. The identification and determination of chlorinated pesticide residues. Analyst 90: 649-656. (15) Mills, P. A. 1959. Detection and semi-quantitative esti- mation of chlorinated organic pesticide residues in foods by paper chromatography. J. Ass. Offic. Agr. Chem. 42: 734-740. (16) Brown, N. J., and A. W. A. Brown. 1970. Biological fate of DDT in a sub-arctic environment. J. Wildl. Manage. 34:929-940. (17) Macek. K. J., and S. Korn. 1970. Significance of the food chain in DDT accumulation by fish. J. Fish. Res. Bd. Can., 27: 1496-1498. 180 Pesticides Monitoring Journal Relations of the Brown Pelican to Certain Environmental Pollutants ' Lawrence J. Bins, Andre A. Belisle, and Richard M. Prouty ABSTRACT Nearly all brown pelican eggs collected from 13 colonies in Soiilli Carolina, Florida, and California in 1969 and from 17 colonies in South Carolina and Florida in 1970 exhibited eggshell thinning. Of the 100 eggs analyzed for residues of pollutants, all eggs contained measurable quantities of DDE; most eggs contained measurable quantities of p.p'-DDD. p,p'-DDT, dieldrin, or PCB's (polychlorinated biphenyls). All eggs contained measurable quantities of mercury. DDE appears to have been responsible for virtually all the egg- shell thinning. There is strong evidence that DDE played a major role in lowered reproductive success in South Carolina and California, and this pollutant appears to be intimately related to the population decline in South Caro- lina. Other pollutants, particularly dieldrin. may have had deleterious effect on reproductive success in South Carolina. Carca.sses of pelicans collected by shooting in Florida and South Carolina in 1970 varied in residue load according to age and geographic location. Birds under 1 year of age contained smaller quantities of residues than did birds 1 year or older. Introduction The brown pelican (Pelecanus occidentalis) has expe- rienced drastic population declines in much of its range in the United States. The first indication of population decline was noted in the early 1960's when the large breeding population of the eastern brown pelican {P. <>. carolmen.sis) in Louisiana was extirpated (/). In South Carolina, the population declined from over 5,000 breeding pairs to approximately 1,000 pairs by the late 1960's (2, 3). In California, near total reproductive failure has occurred in the California brown pelican (P. o. californicus) during the past several years (4. 5). The population in Florida has remained relatively stable over the past 5 years (6. 7: also: L. J. Williams, ^ U.S. Department of the Interior. Bureau of Sport Fisheries and Wild- life. Patuxent Wildlife Research Center, Laurel, Maryland 20810. Vol. 7, No. 3/4, March 1974 personal communication). The agent or agents respon- sible for the disappearance of the Louisiana population remain unknown, but the catastrophe in California has been attributed to the DDT group of insecticides, par- ticularly DDE {4. 8. 9. 10). The objectives of this study are (a) to determine the relation of certain environmental pollutants to popula- tion trends of the eastern brown pelican in Florida and South Carolina, and (b) to examine the relation of these pollutants to reproductive success in South Carolina. Additional residue data are included from the Cali- fornia brown pelican. Eggs and birds from which residue data were determined and herein reported were collected in 1969 and 1970. Sampling Procedures Brown pelican eggs were collected in 1969 from one colony in California (10 eggs), two colonies in South Carolina (49 eggs), and ten colonies in Florida (81 eggs). The eggshell measurements of the eggs collected in 1969 from the southeastern colonies were reported previously (i); and some of the residue data for the eggs from California were previously reported (11). In 1970, an additional 186 eggs were collected: 146 from 15 colonies in Florida and 40 from two colonies in South Carolina (Fig. 1). The eggs were wrapped in aluminum foil and frozen within several days of collec- tion. Shell thickness (shell and shell membranes) was measured at three sites on the waist with a micrometer graduated in units of 0.01 mm. The thoroughly dried shells were weighed to the nearest 0.0001 g. When feasible, one egg was taken from each of 10 nests in each Florida colony; at least 20 were collected from each South Carolina colony. Except for a few instances in 1969, eggs were collected from nests that had no young; eggs in all stages of incubation, both fresh and 181 CAPE ROMAIN DEVEAUX BANK PORT ORANGE CRANE ISLAND BOCA GRANDE- PASS MATLACHA PASS HEMP ISLAND BUCHANAN KEY- MARQUESAS ' KEY FIGURE 1. — Colony sites where brown pelican eggs werL collected in 1970. addled, were collected. In 1969. the eggs were collected in late May or early June except in the Deveaux Bank colony where they were collected in late July. In 1970, eggs were collected in February in three Florida Bay colonies; other colonies were visited in late April or early May. An attempt was made to sample as wide a segment of each colony as possible. TTie South Carolina colonies contain ground-nesting birds with only a few nests in low shrubs: this facilitated uniform sampling of the colony. It was more difficult to obtain a uniform sample in some Florida colonies because the pelicans nest in mangroves and other trees. Pelicans were shot in three areas in Florida and in one area in South Carolina in 1970. Birds were collected in early June in Florida Bay and from July 7 to July 23 in the other areas. Pelicans were selected to represent a varied sample of age and sex. In one instance, a sick individual was collected; all other pelicans appeared normal. In South Carolina, reproductive success was determined by directly counting or estimating the total number of nests and the total number of young fledged from those nests. Nests were counted on Marsh Island in 1969 and 1970 and on Deveaux Bank in 1970. The number of fledged young in each year was estimated as was the count of nests on Deveaux Bank in 1969. Chemical Analyses Eggs were analyzed individually for residues of or- ganochlorine pesticides and their metabolites, poly- chlorinated biphenyls (PCB's), and mercury. The con- tent of each egg was homogenized in a mixer; a 20-g aliquot was removed for pesticide and PCB analysis. A 5-g aliquot was removed for mercury analysis from each egg collected from South Carolina in 1970. The 20-g aliquots were ground with anhydrous sodium sul- fate and extracted for 7 hours with hexane in a Soxhlet apparatus. Extracts were cleaned up by acetonitrile partitioning, and half were saved for PCB analysis. For insecticide analysis, residues in the cleaned extract were separated and removed in four fractions from a silica gel thin-layer plate {12). Each sample fraction was an- alyzed by electron capture gas chromatography on columns consisting of either a 3% OV-1 on Chromo- sorb W H. P. on 80/100 P, a 3% OV-1 7 on Gas Chrom Q on 100/120, or a 3.8% UCW-98 on Chrom W H.P. 80/100. DDT and metabolites in Fractions III or IV were confirmed on a column of 3% XE-60 or 3% QF-1 on Gas Chrom Q 60/80. PCB residues were identified and measured semi-quantitatively by a method involving thin-layer chromatography (13). The average recovery of the chlorinated insecticides and their meta- bolites from fortified eagle tissue ranged form 75 to 112%. The California eggs, after freeze-drying, were analyzed for lead and total mercury by PPB, Incorporated, Columbia, Missouri (now defunct). The lead analysis was done on an atomic absorption spectrometer; a tantalum boat technique was used to increase sensitivity. The 1969 eggs from Florida and >South Carolina were analyzed for total mercury by PPB, Incorporated, and Gulf General Atomic, Incorporated; quantification and identification of mercury in the freeze-dried eggs were made by multichannel gamma ray spectrometry. The analysis for mercury for the Florida Bay eggs and the analysis for lead in eggs not from California were con- ducted by the Environmental Trace Substances Center, Columbia, Missouri. The mercury analysis of the 10 eggs collected in South Carolina in 1970 was for total mercury by a method developed by R. S. Christensen of the WARF Institute. Inc., Madison, Wisconsin (personal com- munication). The procedure involves acid digestion of the tissue and extraction of the mercury from the liquid digest with dithizone (14). Mercury determination was made on the dithizone extract by flame atomic ab- sorption spectrophotometry using a sampling boat tech- nique (15). The average recovery from tissue samples fortified with both inorganic mercury compounds was 91%. The organochlorine residues of the pelican carcasses (body minus skin, head, feet, and gastrointestinal tract) 182 Pesticides Monitoring Journal collected in 1970 and the eggs collected from Florida Bay in 1970 were analyzed by a method different from the procedure used for the other 80 eggs. Use of this method permitted analysis for mirex. which was not feasible using the method described above. The usual Soxhlet extraction with hexane was made on a 10-g aliquot of pelican carcass. An aliquot containing —0.4 g lipid was cleaned up by column chromatrography us- ing the following procedure: Florisil, previously washed and recalcined at 1250°F according to the method of Hall (16). was partly deactivated with water (1-1.5%) to allow dieldrin to elute with the other pesticides and PCB's. A 19-mm-inside-diameter column containing 21 g of the treated Florisil topped with V2 in. sodium sul- fate was prewashed with 50 ml hexane; the sample was added to the column and eluted with 200 ml of 6% ethyl ether in hexane. The Florisil eluate was evaporated to 20 ml and a 5-mI aliquot was transferred to a silicic acid column. The reagents and apparatus used for the silicic acid column procedure were those specified by Armour and Burke (17) but modifications were made in collecting the eluants. The petroleum ether eluate was collected in two separate fractions of 100 and 300 ml, followed by 200 ml of the polar eluate (1% acetonitrile, 19% hexane, and 80% methylene chloride). The three frac- tions were concentrated and analyzed by gas chromo- tography (GC). Using this procedure, mirex was collected in the first 100 ml of petroleum ether eluate. PCB's and DDE were collected in the second fraction; a previous study (18) showed that PCB preparations (Aroclor 1248, 1254, or 1260 as reference) do not interfere in the quantitative determination of DDE unless the ratio of PCB to DDE exceeds 10:1. The third fraction contained the rest of the pesticides. Each fraction was analyzed on a Hewlett Packard 5750 gas chromatograph using a column of 4% SE-30/6% QF-1 on Supelcoport 100/120. Pesticides were quanti- tated by peak height; PCB's were estimated by com- paring the total GC peak heights of PCB's in samples with that of Aroclor 1254. Recoveries from eagle tissue spiked with the organochlorine pesticides and 1254 ranged from 90 to 109%. The polar eluate of some samples was zoned by thin-layer chromatography (12) and run on a 3% SP 2401 column to confirm certain pesticide residues. PCB residues in most samples were confirmed by the thin-layer method of Mulhern et al. (13). The minimum measurable quantity was 0.05 jUg/g for most pesticides. The pelican egg residue measurements were not corrected for recovery values. Residues are expressed on a fresh wet-weight basis. We found that certain external egg measurements (length by breadth) were significantly correlated (P<0.01) with the weight of the contents of fresh eggs (1). The resulting regression equation was used to convert weight of the contents of all eggs to a fresh wet-weight basis (19). For purposes of comparison with other research, the contents of freshly laid brown pelican eggs contained an average of 84% moisture (determined by lyophilization) and 4.4% lipids. The percentage lipids remained essentially uni- form until the embryo reached late development. At this stage (two-thirds or more development) the contents (adjusted to fresh wet weight) contained an average of 3.1% lipids, a significant drop (P<0.01; Student's r-test) from that found in the fresh egg. Romanoff (20) found a decrease of one-third of the lipid content of the hen's egg from laying to hatching. A trace value for the pesticides or their metabolites, lead, or mercury was considered to be <0.1 yu.g/g, and a trace value for the PCB's was considered to be <1.0 fjig/g. In order to quantify trace values and zero values (no residue detected) for statistical tests, the mean of these values was considered to lie halfway between the level of sensitivity and zero; each of these values was assigned this mean. Statistical analyses of the egg data were performed after logarithmic transformation of the residues. Residues in the 20 eggs collected from colonies in Florida Bay were not used in any of the statistical analysis except to show the mean and median for each colony. Results and Discussion RESIDUES Measurable residues of p.p'-DDE were found in the 100 eggs analyzed; residues of p.^^'-DDD, p,p'-DDT, dieldrin, and PCB's exceeded trace values in most eggs (Table 1 ). Measurable quantities of mercury were found in the 80 eggs analyzed for this metal. There was a great deal of variability in the DDE residues: California eggs (1969) had a geometric mean of 71 /xg/g; residues in South Carolina eggs (Cape Romain) varied from 4.45 /ig/g in 1969 to 2.83 in 1970; and residues in eggs from the Florida colonies (1969) averaged 0.69 to 2.48 yu,g/g DDE. Residues of DDE in eggs collected in 1969 from four geographic areas: Florida Gulf Coast, Florida Atlantic Coast, South Carolina, and California, were significantly different (P<0.05) from one another (Table 2). California eggs contained significantly more DDE and DDT than the eggs from the other areas; South Carolina eggs contained significantly more diel- drin. The highest levels of DDD and PCB's were also found in the South Carolina eggs; these residues were significantly higher than in the other areas except California. Excluding mercury, the lowest residues were found in the Florida Gulf Coast eggs. The lowest level of dieldrin was found in the California eggs, and the lowest level of mercury was found in the South Carolina eggs. The DDE:PCB ratio varied from 0.3:1 in the Marquesas Key Colony to 20:1 in the Anacapa Colony. All Anacapa eggs contained small residues Vol. 7, No. 3/4, March 1974 183 of o,p'-DDT and o,p'-DDD; it is extremely rare to find these isomers in tissues of vertebrates (//). Lead residues in the eggs were small; maximum residue was 0.17 fig/g. Most egg residues were usually posi- tively intercorrelated (P<0.05) (Table 3). The excep- tion was mercury which was negatively correlated with most of the other residues. The negative correlations probably occur as a result of a dissimilar pattern of mercury contamination from the organochlorines. The buildup of mercury in the food chain is likely to be of a different nature and of a lower magnitude than that associated with the organochlorines because most of the major forms of mercury in the ecosystem apparently are not lipid soluble. There were some differences be- tween States in the correlations between egg residues. The positive relationships between DDE and the other organochlorines were usually significant. To a lesser ex- tent, this was also true of DDD and the PCB's. In con- trast, the relationship of DDT to the other organo- chlorine residues, although positive, was usually not significant. Tlie exception was in the California series where there was a significant positive relationship be- tween DDT and DDE and between DDT and DDD. In the South Carolina eggs, the negative relationships be- tween mercury and several of the organochlorines were significant. Although the full meaning of the relationship between residues is not clear, it is known that DDT is metabolized in the hen's egg to some extent (21). Con- sequently, there may be a breakdown from DDT to DDD in eggs containing dead embryos since this me- tabolism occurs in avian tissue after death (22). Thus the relationships in Table 3 may not necessarily be repre- sentative of those found in freshly laid eggs. However, it seems certain that the biological magnification of certain organochlorines (p,p'-DDE, p,p'-DDD, dieldrin, and PCB's) resembles a group effect in the pelican egg. That is, organochlorine residues tend to increase or de- crease together, although the level of change for each chemical may be of a different magnitude. Residue data are included for only one pelican found dead in the field (Table 4). This particular bird was observed in tremors on May 8 in the yard of a house located on Plantation Key, Florida. It was found dead on May 9. The cause of death is not known because no indications of serious disease or unduly high residues of pollutants were found. A hemolytic Staphylococcus was isolated from the heart blood, but the significance of this isolation was not determined. The carcass con- tained an array of residues, but these were lower than some of the residues from carcasses of pelicans collected in 1970 (Table 5). The residues in the brain were lower than those considered to be indicative of death from dieldrin (2i), or from DDT or metabolites (24. 25). Residues in the carcasses of birds collected in 1970 were quite variable, but all carcasses contained measurable residues of DDE and all contained at least a trace of PCB's (Table 5). The birds represented a wide range of age and both sexes; thus it would have little meaning to calculate the geometric mean or determine the median residue. The immature birds (1 to 2 years of age) and adult birds (3 years and older) always carried higher residues than did the young of the year. The age at which the brown pelican attains adult plumage is not definitely known; the age brackets for immature and adults pelicans are approximate. There was an indica- tion that residues increased with age in young of the year, but this was not universally true. Eggshell thicknesses of eggs from Florida Bay were near normal, and residues of DDE in these eggs aver- aged near 1 /ig/g, which was generally lower than averages found in eggs from other colonies. Residues were much lower in adult and immature pelicans from Florida Bay than were those detected in birds from the other areas. Perhaps most of these birds spend the entire season in Florida Bay where they probably are exposed to a lower level of contamination. However, we currently have no explanation for the similar magnitude of residues in young of the year from all areas. The pelicans may winter in areas other than those in which they breed (26). This is particularly probable of pelicans breeding in South Carolina; most of the birds winter on the east coast of Florida, a few winter in South Carolina, and some winter in Cuba and other southern localities. The east coast and west coast pelicans in Florida gen- erally remain apart from one another. There are no data for birds banded in Florida Bay. Except for birds from Florida Bay, there are no clearcut differences, by locality, in the magnitude of residues in the carcasses; this may be due partly to the small sample size. Residues of DDE and PCB's in carcasses of several of the im- mature and adult birds seem unduly high, but there is no current basis for associating these residues with adverse biological effects. EGGSHELL MEASUREMENTS To determine whether the brown pelican eggshell thickness measurements varied with time in the pre- 1947 sample, the Florida thickness measurements were grouped by decade from 1890-1899 to 1930-1939. Thickness by decade ranged from 0.549 mm in the 1920-1929 sample to 0.568 mm in the 1910-1919 sample; an analysis of variance indicated no significant difference (P>0.05) between decades (Table 6). Thus all the pre- 1947 measurements were combined to com- pare with the 1969 and 1970 thickness data. There were insufficient measurements in the pre-1947 thickness measurements from South Carolina with which to com- pare decade differences. Anderson and Hickey (27) re- ported the eggshell thickness of 1 1 species of birds by decades up to 1939; only one species exhibited significant decade differences. Comparisons of the 1969 mean shell thickness with the 1970 mean shell thickness of eggs from each of nine 184 Pesticides Monitoring Journal colonies in Florida and two colonies in South Carolina showed that the yearly means were significantly different (P<0.05, Student's /-test) in only one colony: Boca Grande Pass. The thickness of shells from this colony was 0.559 mm in 1969 compared to 0.517 in 1970. The eggshell thicknesses of eggs collected in 1970 in Florida and South Carolina were similar to those ob- tained in 1969 (Tables 7 and 8). The mean eggshell thickness of the Florida eggs collected in 1970 was 0.512 mm, a decrease of 8.1% from the pre-1947 measurements. As in 1969, the thinnest eggs from the southeastern colonies were found in South Carolina; the thickness was approximately 17% less than that of shells in the pre-1947 museum collections. In each State mean eggshell thicknesses for both 1969 and 1970 were significantly less (P<0.05) than the pre-1947 eggshell thickness; however, there were no significant differences between the 1969 and 1970 means (Table 8). The 17% eggshell thinning observed in South Carolina was associated with subnormal reproductive success. We saw several instances of extremely thin eggshells in the South Carolina colonies in both years. Usually, the en- tire clutch exhibited the extreme thinning, and all the eggs were broken in some nests. The thinnest egg was collected from the Cape Romain colony (33.6% thinner than the pre-1947 mean); it apparently had been laid only hours before collection. Crushing of thinshelled eggs early in the incubation period provides an unknown degree of bias favoring collection of eggs with thicker eggshells. The mean eggshell thickness of eggs from the Florida Bay colonies varied from 2 to 6% less than the pre- 1947 mean. Eggshell thinning in the other two major geographic areas of Florida was somewhat greater: 5 to 8% in the Gulf Coast eggs and about 11% in the Atlantic Coast eggs. It is unknown whether reproduction is impaired when shell thinning reaches 11%. In this study, we have used eggshell thickness or percent- age of pre-1947 thickness in preference to eggshell weight or the thickness index. Each of the four measure- ments is significantly correlated (P<0.01) with the others (Table 9). Therefore it follows that any one of the measurements may be used. An important reason for using thickness is that this is the only measurement that can be taken from crushed or hatched eggs. The reason for using the percentage of the pre-1947 thickness is that thickness measurements for different subspecies or their groups can be combined for analysis of the data; this is not possible using thickness alone due to inherent differences by geographic area in the pre-1947 measure- ments. It is also possible to compare the relationships between thickness and residue level in eggs of different species. Anderson and Hickey (27) found a significant correlation between eggshell weight and thickness index in each of 10 species of birds. RELATIONSHIP BETWEEN RESIDUES AND EGGSHELL MEASUREMENTS Most residues in brown pelican eggs have been shown to be significantly correlated with the eggshell measure- ments (9). Mercury was usually positively correlated with the thickness measurements, and in one instance the correlation coefficient was significant (P<0.05). By use of stepwise regression, DDE was the only residue that consistently accounted for a significant amount of variability in the three eggshell measurements (9). The intimate relationship between DDE and eggshell thinning in the pelican is most impressive, especially considering that the data are taken from wild birds (Fig. 2). Of course, there are natural factors that may influence the thickness of birds' eggshells that were not considered in the analysis. The eggshell thinning potential of cer- tain other pollutants that may occur in pelican eggs has not been thoroughly tested and analytical methods for detecting them are limited. DDE has significantly altered the shell thickness of eggs laid by certain captive birds (28, 29, 30, 3]). and this compound is universally dis- tributed in wild birds. Thus it is the most likely candidate to be responsible for most of the thinning of eggshells of wild birds. Lead, mercury, and PCB's have been suggested as the shell-thinning agents in the California pelicans; however, residues of mercury and PCB's are no higher in the California eggs than in the southeastern eggs. In all eggs, levels of lead were very low in these eggs and it seems unlikely that lead is responsible for the thinning. Connors et al. (32) compared concentrations of nine metals in pelican tissue from Florida and Cali- fornia; residue levels were similar in both areas except that mercury levels were higher in Florida. They con- sidered it unlikely that eggshell thinning and reproduc- tive failure in the brown pelican in California were in- duced by any of the nine metals. The rate at which DDE thins eggshells of the brown pelican is greatest when the residues are small (8). This relationship is essentially linear on a logarithmic scale. iin , IIU u! 105 - Y = 96 410 - 16 509 loa,^ X z ^ 100 _ ^^ r^= 0,92 (P<0.01) u "^>, ^5 95 - "^v • . O i 90 - / -j.^ »- iU 2 5 85 - u 0 "^-^^ S O 80 — ■^s. a. >" K 75 — '^■s.^ •» £ 70 - '^■s.^ i 65 _ ^■'^> " 0< ' 1 10 100 DDE («»/>) FIGURE 2. — Associalion of DDE residues in brown pelican eggs from nine collections in Florida [•], Iwo colonies in Soiiih Carolina [A], and one colony in California [*] witit percent of pre-1947 eggshell thickness. Vol. 7, No. 3/4, March 1974 185 The calculated no-effect level is 0.5 /xg/g of DDE in the egg, although this level may actually be lower than calculated. Thinning reaches 4% at 1 fig/g, 15% at 5 fig/g, 20% at 10 fig/g, and 40% at 100 /xg/g. The logarithmic relationship of DDE to thinning also ap- peared to be present in the double-crested cormorant (Phalacrocorax auritus) (33) and the prairie falcon {Falco mexkanus) (34). Further research is required to define the mathematical relationships of residues to other biological effects. EFFECTS OF RESIDUES ON REPRODUCTIVE SUCCESS Data are available from e.xperimental studies that in- dicate the relationship between eggshell thinning and reproductive success. In experimental studies with DDE in mallards (Anas platyrhynchos) and black ducks (Anas nibripes) where thinning was less than 18%, increased embryonic mortality, and increased egg breakage were found; both factors resulted in decreased reproductive success (28, 29). Other factors associated with eggshell thinning that are found in wild birds are increased egg eating by the parents (35), decreased clutch size, and increased embryonic mortality (36). It seems likely that DDE is one of the principal agents responsible for the decreased productivity of the pelican in South Carolina (Table 10). However, there are three other pollutants that may have adversely influenced reproductive suc- cess. The major suspect is dieldrin. Experimental studies have demonstrated that, even at high residue levels in the egg, dieldrin has little or no effect on eggshell thick- ness in the mallard (37) or ring-necked pheasant (Pliasi- aniis cokhicus) (38). However, dieldrin has affected reproductive success in experimental ring-necked pheasants (39). The mean dieldrin level in both South Carolina pelican colonies was near 1 /xg/g in 1969. The dieldrin levels in the Cape Romain colony dropped to 0.62 fj.g/ g in 1970. Most of the dieldrin levels in eggs were near the levels thought to cause a lowered reproductive success in the Scottish golden eagle (Aqtiila chrysaelos) (40, 41) and in bald eagles (Haliaeeliis leucovephaliis) in Maine (42). Species are not equally sensitive to dieldrin; reproductive success in the gallinules (Porphy- nda martinica and Galliniila cliloropus) seemed to be normal even though dieldrin levels in eggs averaged near 4 /xg/g (43. 44). Potts (10) found egg breakage and some evidence of lowered reproductive success in the shag (Phalacrocorax arislotelis); dieldrin represented the only chlorinated hydrocarbon pesticide present in appreciable quantities. Potts concluded that much of the egg breakage was caused by polygyny. Apparently, adverse reproductive effects in the shag did not appear until dieldrin residues in the egg exceeded 2 /xg/g of dieldrin. These studies demonstrate that different species may respond quite differently to the same toxicant. Judging from the extreme sensitivity of the brown pelican to DDE-induced eggshell thinning, one would suspect that the pelican is also extremely sensitive to dieldrin. However, further study is needed to define this relationship. PCB's constitute another group of pollutants that may be adversely affecting reproductive success, but this has not been demonstrated in wild birds. The experimental evidence regarding the ability of PCB's to thin eggshells and adversely affect reproductive success is con- flicting. In one study with chickens, significant adverse effects on productivity occurred when the chickens were fed 10 and 100 /xg/g of Aroclor 1242 or 100 /xg/g of Aroclor 1254. The effects were reduced egg production and hatchability and thinning of eggshells (45). In a study with mallards, no eggshell thinning or other adverse reproductive effects were observed when Aroclor 1254 was included in the diet at 25 /xg/g; bobwhite quail showed no shell thinning or other adverse re- productive effects when fed 50 /xg/g of Aroclor 1254 (46). Pheasants given a 50-mg capsule dose of Aroclor 1254 weekly for 17 weeks produced fewer eggs than did controls, and significantly more young died while pipping the shell. Chick survival was also adversely affected by Aroclor 1254, but neither eggshell thickness nor fertility was affected (47). In ring doves (Streptopelia risoria) fed 10 /xg/g of Aroclor 1254 for two years, embryonic mortality and chromosomal alterations were found only in the second year (48). Although not all the PCB preparations have been tested to determine whether they will thin eggshells, it appears unlikely that they are contributing significantly to thinning in the pelicans (9). However, the possibility still exists that the PCB's may also be involved in the lowered reproductive success. Mercury also may be adversely affecting reproduction in the pelican. In a study with ring-necked pheasants fed 10 /xg/g of ethyl mercury p-toluene sulfanonilide, egg production was decreased by 50-80% and embryonic mortality was increased in the few eggs that were laid. Eggshell thickness was not significantly reduced in the birds treated (49). In pheasants fed grain treated with methylmercury dicyandiamide, reduced egg production and reduced hatchability occurred. A large number of eggs without shells were found in some groups, but eggshell thickness was not measured (50). In another study in which pheasants were fed grain treated with methylmercury dicyandiamide, reduced hatchability was noted after nine days on dosage; eggshell thickness was not measured (51). In these studies with pheasants, the mercury level in the eggs ranged from 1.3 to 2.0 /xg/g (51), from 0.9 to 3.1 (48). and from 0.5 to 1.5 /xg/g (50). In a study with Coturnix quail fed 1 /xg/g of mercuric chloride, the eggshell thickness was significantly lower than in controls, yet the eggs contained only 0.06 /xg/g of mercury. At the same time, egg production, hatchability, and fertility were unaffected even at a dietary level as high as 8 /xg/g (52). 186 Pesticides Monitoring Journal In wild birds, Vermeer {53) found mercury levels of 0.5 to 2.0 fig/g in eggs collected from successful herring gull clutches; an egg from each of two clutches that produced no young contained 1.3 and 2.4 /xg/g. Six of the 21 pelican eggs from South Carolina contained 0.5 ug/g or more of mercury, a level associated with adverse effects on reproductive success in one of the experimental studies with pheasants. Due to differences in species susceptibility, mercury must remain suspect as a causa- tive agent for at least a small portion of the lowered reproductive success in the brown pelican in South Carolina. The herring gull appears to be much more resistant to DDE-induced eggshell thinning (36) than the brown pelican. Perhaps the case against mercury weakens when one considers that 16 of the 49 eggs from Florida contained 0.5 jjLg/g or more mercury, and one on the verge of hatching contained 1.43 //g/g (Table 1). The pelican population in Florida has been considered stable over the past five years, and reproductive success is considered normal (54). An occasional egg from the Atlantic Coast of Florida contained levels of dieldrin or DDE that are thought to be deleterious. However, the bulk of the residues in all areas of Florida are low enough that one would not expect these residues to induce widespread, long-term, adverse effects on the populations there. It is probable that several pollutants are involved in the population decline of brown pelicans in South Carolina. There is a possibility that other pollutants not identified in this study may also have played some role. Storms and high tides have temporarily disrupted nest- ing activities at times, but the effects of these factors is thought to be minimal because the brown pelican is known to be a persistant renester (55). Predation appears to be a minor factor in loss of eggs and young in South Carolina. TTie islands are isolated, and mammalian predators are not likely to gain access to them. If they did, they would not likely establish permanent residence; cover is sparse, and severe storms sometimes inundate the islands. There are no effective avian egg predators around the colonies except for the herring gull (Lams argentatiis) and the ring-billed gull (Lams delawarensis). These are present in small numbers, and they have not been observed eating pelican eggs. Laughing gulls (Lams atricilla) nest in large numbers in each colony, but they apparently have little facility for preying on pelican eggs. THE POPULATION DECLINE IN SOUTH CAROLINA Historically, little is known of the numbers of brown pelicans occurring in the colonies in South Carolina; however, we have a fairly good record of the numbers associated with the colony on the Cape Romain Na- tional Wildlife Refuge since the 1930's. The pelicans on the Refuge have nested on Marsh Island (Vessel Reef), Bird Bank, White Banks, Cape Island, and Raccoon Key (Sandy Point) at various times in the past; as many as three colony sites on the refuge have been occupied at one time (Table 11). The breeding population on the Cape Romain National Wildlife Refuge has remained relatively stable through the years. Sprunt and Chamberlain (55) reported a maxi- mum of 800 breeding pairs in 1946. However, E. Milby Burton (personal communication) counted over 1,000 nests in one colony on the refuge during the 1930's. The number of estimated nesting pairs on the Cape Romain Refuge ranged from an estimated 500 to 650 from 1962 through 1968; yet a thorough count in 1969 re- vealed over 1,000 nests. From 1947 to the early 1960's, Deveaux Bank was ap- parently the major colony; some interchange of breed- ing birds apparently occurred between this colony and the Cape Romain colony. There is still apparently a great deal of interchange between the two colonies, but Cape Romain is now the major colony. In 1969, the birds began to nest early on Deveaux Bank, but they deserted in the nest-building phase (T. A. Beckett, III, personal communication), and most of these birds probably moved to Marsh Island. In 1970, nesting pairs increased on Deveaux Bank, and although breeding pairs decreased in the Cape Romain colony, it still contained more breeding birds than Deveaux Bank. With the apparent movement of breeding birds between the two colonies from year to year, population trends in South Carolina seem to be valid only if both colonies are considered together. Several other islands have been used for nesting sites in South Carolina (Table 11). Existence of some of these colonies is known only from published oological records (/) and from data taken from eggs in the Charleston Museum. The record of the pelican colony at the mouth of the Stono River is based on circumstantial evidence, but the island is still in existence and is considered suitable for brown pelican nesting. The exact location of the Bay Point colony near Beaufort, where eggs were collected in 1901, is not known because there are two locations called Bay Point, one on either side of Beaufort. It is not known whether a suitable nesting island is present at either of these locations. Thus peli- cans have nested on at least 1 1 sites in South Carolina. There are relatively few islands in South Carolina that are acceptable to the brown pelican as nesting sites. Two principal requirements of pelican nesting islands seem to be isolation from mammalian predators, particularly raccoons (Procyon Lotor), and sufficient elevation of the islands to prevent widescale flooding of nests. Of the two islands currently used for nesting, the pelicans have nested on Marsh Island continuously since 1967 and on Deveaux Bank continuously since about 1946. There are no known nesting records for pelicans on Deveaux Bank until 1946; the Bank was used as a bombing range Vol. 7, No. 3/4, March 1974 187 in World War II. Marsh Island has been used for nesting at various times since at least 1901. There is some evidence that two colonies of pelicans existed near Beaufort in 1943. A collector (E. J. DeCamps) took eggs from both colonies; he listed one nesting island as Bird Bank. St. Helena Sound (now known as Egg Bank), but he did not list a name for the other island, indicating only that it was 18 miles east of Beaufort. Egg Bank is 12 miles east of Beaufort, while Bay Point (Edisto Island) is approximately 18 miles east of Beau- fort. Thus it seems very likely that two colonies existed near Beaufort in 1943, and that pelicans from both colonies moved to Deveaux Bank. Mason (26) described the colony on Egg Bank as small, but gave no population estimate. It seems clear that the pelicans on Deveaux Bank have experienced a drastic population decline beginning at least 10 years ago. With the large nesting population of over 5,000 nesting pairs, the population decline may have progressed for several years before it was noticed. By 1969, the population on Deveaux Bank had dwindled to approximately 250 nesting pairs; the number in- creased to 479 pairs in 1970. My (L.J.B.) experience with the island since 1969 leads me to believe that space for at least 2,000 to 3,000 nests is currently available. The most accurate data on the number of breeding birds and reproductive success in South Carolina were ob- tained in 1969 and 1970. Over this period the number of nests was actually counted except for an estimate for Deveaux Bank in 1969. The number of young fledged was estimated for each colony. According to age- specific mortality data obtained from birds handed during the period 1946 to 1966 in North and South Carolina, approximately 1.2 to 1.5 young must be fledged per breeding female per year in order to maintain a stable population (56). Based on this estimate, the number of young fledged in South Carolina in 1969 and 1970 was insufficient to maintain a stable popula- tion. The level of eggshell thinning (17%) in South Carolina is within the 15 to 20% level of thinning that has been associated with population declines of certain birds when such thinning occurs consistently over a period of years (27). The decline is greater than that recorded in black ducks and mallards fed DDE; these birds have also experienced lowered reproductive success (28, 29). Conclusion DDE is the agent responsible for all or most of the eggshell thinning of brown pelican eggs observed in all areas where eggs were collected. DDE, because of its propensity for inducing deleterious effects in experi- mental birds, is suspected of being the principal agent in the lowered reproductive success and resultant popu- lation declines in South Carolina and California pelicans. However, other pollutants, particularly dieldrin, may adversely affect reproductive success in ways unrelated to shell thinning. A cknowledgments We gratefully acknowledge the important contribution of E. H. Dustman and Lucille F. Stickel who reviewed the manuscript and aided in planning the study, and Robert G. Heath who reviewed the manuscript and ofi'ered advice on statistics. We thank Daniel W. Ander- son and Joseph J. Hickey for providing computer printouts of brown pelican eggshell data. We are grate- ful to Louis Locke for providing the necropsy data on the pelican that died. We appreciate the provision of specimens of brown pelicans by the Southeastern Di- sease Laboratory, Athens, Georgia. We thank the following people who aided in the egg collections: Travis McDaniel, James Utsey, Ted Beckett III, Lovett Wil- liams, Karl Eric Tolomen, Larry Martin, Alexander Sprunt IV, Eugene Knoder, Fred Lesser, Lawrence Wineland, Ralph W. Schreiber, James O. Keith, William O. Robertson, Charles LeBuff, Jr., Ed CoUinsworth, Larry Shanks, and John Galyen. Mr. Ted Beckett III de- serves special recognition for bringing the plight of the pelican in South Carolina to official attention. 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No. 1. 99 pp. TABLE 1. — Residues of environmental pollutanls in brown pelican eggs Colony /io/o (Fresh wet weight) p.p'-DDE p,p'-DDD p.p'-DDT DiELDRIN PCB'S Mercury SOUTH CAROLINA, 1969 Cape Remain 4.22 0.75 0.77 0.78 5.4 0.65 ND^ Tr3 3.64 0.91 0.99 0.60 3.9 0.34 ND Tr 5.38 1.79 1.70 1.10 3.8 0.12 ND Tr 3.25 1.36 0.83 0.78 4.8 0.29 ND Tr 6.55 1.62 1.45 1.63 5.5 0.31 ND Tr 4.42 0.94 0.99 1.37 5.7 0.34 ND Tr G.M.' 4.45 1.17 1.08 0.98 4.79 0.31 _ Median 4.32 1.15 0.99 0.94 5.10 0.33 — — Deveaux Bank 10.60 2.88 1.86 1.31 11.0 0.26 ND Tr 8.70 1.63 ND 0.70 6.6 0.18 ND Tr 4.55 1.59 ND 0,60 10.4 0.28 ND Tr 6.32 2.21 ND 1.25 5.8 0.26 Tr Tr 3.93 1.19 Tr 0.87 3.8 0.25 ND Tr CM. 6.36 1.81 0.90 6.99 0.24 Median 6.32 1.63 — 0.87 6.60 0.26 — — SOUTH CAROLINA, 1970 Cape Remain 0.80 0.20 0.20 0.20 2.0 0.90 ND NRii 3.30 0.70 0,90 0.80 4.0 0.50 Tr NR 2.00 0.80 0.70 0.60 4.0 0.40 ND NR 2.30 0.60 0.50 0.50 3.0 0.40 ND NR 8.80 0.80 0.70 1.30 6.0 0.30 Tr NR 7.80 1.30 0.80 1.30 8,0 0.30 Tr NR 3.00 0.80 0.60 1.00 6,0 0.60 Tr NR 2.10 0.40 0.50 0.40 4.0 0.50 ND NR 1.70 0.50 0.50 0.30 4.0 0.50 ND NR 3.70 1.40 0.80 0.90 8.0 0.30 Tr NR G.M. 2.83 0.66 0.58 0.62 4.52 0.44 Median 2.65 0.75 0.65 0.70 4.00 0.45 — — 190 Pesticides Monitoring Journal TABLE 1. — Residues of environmental poUulants in brown pelican eggs — Continued Colony /iO/G (Fresh wet weight) p,p'-DDE P,p'-DDD p,p'-DDT DiELDRIN PCB's Mercury HE' FLORIDA ATLANTIC COAST, 1969 Port Orange 1.72 0.24 0.45 ND 1.7 0.48 ND Tr 0.16 0.34 0.12 ND 6.9 0.35 ND Tr 5.93 1.74 Tr 0.39 7.1 0.23 ND Tr 2.36 1.53 ND 0.66 2.7 0.37 ND Tr 1.77 1.07 0.41 0.75 5.3 0.12 ND Tr G.M. 1.47 0.75 0.14 0.22 4.12 0.28 — — Median 1.77 1.07 0.12 0.39 5.30 0.35 — — Cocoa Beach 4.03 1.18 0.88 1.52 7.5 0.20 0.10 Tr 2.37 0.80 0.56 0.39 2.4 0.44 ND Tr 3.49 0.81 0.90 0.67 4.6 0.36 ND Tr 3.07 0.92 0.67 0.89 7.4 0.29 Tr Tr 0.92 0.18 0.42 0.29 1.3 1.48 ND Tr G.M. 2.48 0.66 0.66 0.63 3.80 0.42 Median 3.07 0.81 0.67 0.67 4.60 0.36 — — Pelican Island 1.14 1.99 0.66 0.55 1.3 0.39 0.29 Tr 2.28 1.75 0,56 0.57 2.8 0.22 ND Tr 1.06 0.19 0.30 0.10 1.4 0.41 ND Tr 2.48 0.67 0.99 0.32 2.4 0.36 Tr Tr 6.01 1.98 0.22 1.09 5.5 0.34 Tr Tr G.M. 2.10 1.00 0.47 0.41 2.32 0.34 Median 2.28 1.75 0.56 0.55 2.40 0.36 — — Fort Pierce 2.81 1.09 0.67 0.57 3.9 0.48 ND Tr 2.11 0.83 0,30 0.54 1.9 0.68 ND Tr 1.54 0.72 0.38 0.20 1.4 0.70 ND Tr 3.39 0.97 0.67 0.28 2.4 0.52 ND Tr 3.15 1.01 0.66 0.25 2.5 0.57 ND Tr 3.00 1.23 0.67 0.31 1.9 0.16 ND Tr 1.74 0.83 0.56 0.26 1.0 0.38 ND Tr G.M. 2.44 0.94 0.54 0.32 1.98 0.46 Median 2.81 0.97 n,66 0.26 1.90 0.52 — — FLORIDA GULF COAST, 1969 Cedar Key 0.98 0.31 0.20 Tr Tr 0.47 ND Tr 0.85 0,31 0,14 Tr Tr 0.16 ND Tr 0.84 0.41 0.22 0.15 Tr 0.18 ND Tr 5.54 0.96 0,39 Tr 4.2 0.35 ND Tr 1.65 0.59 0.30 0.12 1.4 0.31 ND Tr 1.00 0.20 0.27 Tr Tr 0.48 ND Tr 1.32 0.23 0.26 Tr 1.2 0.49 ND Tr G.M. 1.36 0.37 0.24 0.08 0.89 0.32 _ Median 1.00 0.31 0.26 0.05 0.50 0.35 — — Pinellas 1.23 0.63 0.44 0.13 1.6 0.40 Tr Tr 1.72 0.65 0.52 0.26 1.8 0.17 Tr Tr 2.44 0.99 0.57 0.27 1.5 0.41 Tr Tr 3.78 1.95 ND 0.40 2.9 1.21 Tr Tr 1.42 0.62 0.54 Tr 1.1 0.66 ND Tr G.M. 1.94 0.87 0.32 0.18 1.69 0.47 _ _ Median 1.72 0.65 0.52 0.26 1.60 0.41 — — Boca Grande Pass 1.18 0.29 ND 0.11 Tr 0.43 ND Tr 0.46 0.12 0.11 Tr Tr 0.16 ND Tr 0.78 0.23 ND Tr Tr 0.42 ND Tr 0.70 0.36 0.24 0.21 Tr 0.45 ND Tr 0.52 0.15 0.22 Tr Tr 0.40 ND Tr G.M. 0.69 0.22 0.11 0.09 0.50 0.35 _ _ Median 0.70 0.23 0.11 0.05 0.50 0.42 — — Hemp Island 1.76 0.37 0.33 0.17 2.0 0.24 ND Tr 1.87 0.45 0.52 Tr Tr 0.59 ND Tr 1.86 0.65 0.52 0.15 Tr 0.78 ND Tr 1.19 0.24 0.19 Tr Tr 0.62 ND Tr 1.66 0.52 0.32 0.11 Tr 0.86 ND Tr G.M. 1.65 0.42 0.35 0.09 0.66 0.57 _ _ Median 1.76 0.45 0.33 0.11 0.50 0.62 — — Matlacha 1.32 0.19 0.22 Tr 1.0 0.75 ND Tr 3.01 1.51 0.71 Tr 2.3 1.47 Tr Tr 1.44 1.02 0,39 0.22 1.4 0.86 ND Tr 2.17 0.70 0.39 0.10 1.0 0.82 ND Tr 0.90 0.28 0.21 Tr Tr 0.50 ND Tr G.M. 1.62 0.56 0.35 0.08 1.10 0.83 _ _ Median 1.44 0.70 0.39 0.05 1.00 0.82 — — Vol. 7, No. 3/4, March 1974 191 TABLE 1. — Residues of environmental pollutanls in brown pelican eggs — Continued Colony iJLG/a (Fresh wet weight) p,p'-DDE P,p'-DDD p.p'-DDT DiELDRIN PCB's Mercury HEi FLORIDA, FLORIDA BAY, 1970 Nest Key 0.81 ND ND ND 1.1 0.98 ND Tr 0.65 0.16 ND ND Tr 0.29 ND Tr 1.59 0.34 0.17 0.28 2.5 0.78 ND Tr 0.90 0.12 ND ND 0.6 0.38 ND Tr 1.72 0.36 0.16 Tr 1.4 0.84 ND Tr G.M. 1.05 0.16 — 0.9 0.59 — — Median 0.90 0.16 — — I.l 0.78 — — Buchanan Key 2.87 0.50 0.35 0.33 2.7 0.94 ND Tr 0.62 0.13 ND ND Tr 0.59 ND Tr 1.66 0.10 ND 0.15 1.8 0.86 ND Tr 0.51 0.18 ND ND Tr 0.49 ND Tr 1.15 0.20 0.13 0.14 1.3 0.94 ND Tr G.M. 1.11 0.19 0.8 0.74 Median I.I5 0.18 — — 1.3 0.86 — — Fanny Key 0.56 0.15 ND ND Tr 0.51 ND Tr 0.68 0.10 ND ND Tr 0.47 ND Tr 0.96 0.21 ND ND 0.6 0.09 ND Tr 0.40 Tr ND ND Tr 0.57 ND Tr 1.64 0.23 0.24 ND 2.1 O.ll ND Tr G.M. 0.75 0.13 _ 0.5 0.27 Median 0.68 0.15 — — Tr 0.47 — — Marquesas Key 1.07 0.12 0.15 ND Tr 0.35 ND Tr 0.82 ND 0.11 ND Tr 0.45 ND Tr 1.46 0.14 0.25 ND Tr 0.53 ND Tr 1.20 0.14 0.12 ND Tr 0.45 ND Tr 1.45 0.14 0.16 ND I.I 0.54 ND Tr G.M. 1.17 0.11 0.15 0.3 0.46 Median 1.20 0.14 0.15 — Tr 0.45 — — CALIFORNIA. 1969 Anacapa" 76.1 1.3 1.9 0.2 8.0 0.42 ND Tr 50.6 1.4 1.9 0.1 5.0 0.36 ND Tr 135.0 2.4 3.8 0.2 12.0 0.31 ND Tr 60.2 0.3 0.6 Tr 3.2 0.17 ND Tr 39.5 0.5 1.2 Tr Tr 0.40 ND Tr 97.8 3.4 4.6 0.1 8.0 0.30 ND Tr 63.2 1.3 1.6 Tr 5.0 0.56 ND Tr 65.0 0.9 1.5 Tr Tr 0.34 ND 0.17 70.0 1.3 1.4 Tr 6.0 0.31 ND Tr 98.4 1.5 1.9 0.2 4.0 0.33 ND Tr G.M. 71.35 1.18 1.76 0.09 3.60 0.34 0.06 Median 67.50 1.30 1.90 0.08 5.00 0.34 — 0.05 ^ HE = Heptachlor epoxide. - ND — No residue detected. ■'' Tr — Trace of residue; a trace is considered <1.0 /zg/g for PCB's and <0.l //g/t: for all other residues. * G.M. = Geometric Mean. f^ NR — Analysis not run. " Each of the 10 eggs from California contained from trace to 0.2 /ig/g of both o.r'-DDT and o,p'-DDD. TABLE 2. — Comparisons of brown pelican egg residues by geographic areas, 1969 Number OF Eggs Geometric mean (iio/oy Area p.p'-DDE p.p'-DDD p,p'-DDT DiELDRIN PCB'S Mercury Florida Gulf 27 1.37 A = 0.43 A 0.25 A 0.10 A 0.89 A 0.46 A Coast (1.09-1.72) (0.33-0.57) (0.19-0.34) (0.07-0.12) (0.68-1.16) (0.36-0.57) Florida Atlantic 22 2.24 B 0.83 B 0.40 A 0.36 B 2.81 B 0.37 AB Coast (1.60-3.13) (0.61-1. 14) (0.27-0.60) (0.24-0.53) (2.11-3.74) (0.29-0,48) South Carolina II 5.24 C 1.43 C 0.37 A 0.94 C 5.68 C 0.28 B (4.08-6.72) (1.09-1.87) (0.13-1.09) (0.77-1.16) (4.45-7.26) (0.21-0.36) California 10 71.70 D 1.18 BC 1.76 B 0.09 A 3.60 BC 0.42 AB (55.38-91.93) (0.71-1.94) 1 1.17-2.65) (0.06-0.14) (1.63-7.95) (0.24-0.71) ^ 95% confidence limits in parentheses. - A significant difi'erence (P<0.05) among means of a chemical is indicated for those residues not sharing a common letter. Means were separated using Duncan's New Multiple Range test with Kramer's extension for unequal replication. {Kramer. C. Y. 1956. Extension of multiple range tests to group means with unequal numbers of replications. Biometrics, 12: 307-310.) 192 Pesticides Monitoring Journal TABLE 3. — Association of egg residues with one another, egg basis Chemical Simple correlation coefficient DDD DDT DiELDRIN PCB's Mercury CALIFORNIA DDE 0.698 1 0.679 1 0.588 ' 0.655 1 -0.153 DDD 0.950 = 0.577 0.620 0.350 DDT 0.609 0.500 0.310 Dieldrin — — 0.583 0.076 PCB's — — — — -0.050 SOUTH CAROLINA DDE 0.835 = 0.038 0.845 = 0.751 = -0.698 = DDD -0.037 0.767 -■ 0,732 = -0.803 -' DDT 0.259 -0.010 0.100 Dieldrin — 0.618 - -0.555 = PCB's — — — — -0.401 FLORIDA DDE 0.732 = 0.314' 0.531 - 0.559 - 0.032 DDD 0.272 0.647 - 0.632 - -0.025 DDT 0.262 0.239 0.033 Dieldrin — 0.610 - -0.245 PCB's — — — -0.217 1 P<0.05 = P<0.01 TABLE 4. — Residues of environmental pollutants in an adult male town pelican that died in tremors lia/a (WET WEIGHT) Chemical Carcass Brain p.p'-DDE 11.04 11.30 p,p'-DDD 2.80 2.17 p,p'-DDT 0.31 1.26 Dieldrin 1.24 1.82 HE Tr Tr PCB's 20.0 10.0 Mirex NR NR Mercury 1.57 NR TABLE 5. — Residues of environmental pollutants in carcasses of brown pelicans Approximate Age Sex mg/g (wet weight) p,p-DDE p.p'-DDD p.p'-DDT Dieldrin PCB's Mirex SOUTH CAROLINA 1 week unki 0.79 ND ND 0.19 1.3 ND 6 weeks 9 0.20 ND ND ND Tr ND 6 weeks unk 0.29 ND ND ND Tr ND Immature 9 9.20 0.74 0.12 1.50 19.0 0.22 Adult d 25.20 0.84 0.38 0.84 35.0 1.06 FLORIDA; ATLANTIC COAST 4 weeks 9 0.10 ND ND ND Tr ND 10 weeks unk 0.37 1.21 0.51 0.44 7.5 ND 13 weeks d 1.35 0.54 ND 0.34 3.3 ND Immature 9 15.00 1.90 0.69 1.60 29.0 0.20 Adult 9 8.00 0.76 ND 0.61 12.0 0.20 FLORIDA: FLORIDA BAY 3 weeks unk 0.34 ND ND ND Tr ND 7 weeks 9 0.29 ND ND ND Tr ND Immature rf 1.20 0.46 0.12 0.13 1.0 ND Adult d 3.65 0.70 0.38 0.47 4.4 ND Adult 9 1.20 0.38 ND ND 3.0 ND FLORIDA: GULF COAST 1 week unk 0.13 ND ND ND Tr ND 4 weeks unk 0.26 0.10 0.79 ND 1.2 ND 14 weeks 9 1.00 1.10 0.17 0.29 3.5 0.17 Immature - d 4.55 0.84 ND 0.60 19.0 0.31 Immature d 31.00 1.90 1.20 1.80 34.0 0.30 Adult 5 9.60 0.63 ND 0.74 19.5 1.45 1 Sex not determined. = Sick bird. Vol. 7, No. 3/4, March 1974 193 TABLE 6.- -Brown pelican pie-1947 eggshell thickness by decades, Florida Number of Eggs Thickness, mm Decade Mean h Standard Error 1890-1899 1900-1909 1910-1919 1920-1929 1930-1939 44 12 33 39 38 0.560 ± 0.006 1 0.566 ± 0.008 0.568 It 0.007 0.549 ± 0.005 0.553 ± 0.006 Means not significantly different (P>0.05) as tested using analysis of variance. Eggs from 1880-1889 omitted due to small sample size. TABLE 9. — Association of eggshell measurement param- eters witli one another, egg basis Parameter Simple correlation coefficient ^ Weight Thickness Index Percent of Pre-1947 Thickness FLORIDA SOUTH CAROLINA, AND CALIFORNIA Thickness Weight Thickness Index 0.832 0.893 0.849 0.998 0.831 0.903 P<0.01 TABLE 7. — Thicknesses of brown pelican eggshells from 17 colonics, 1970 Colony Number of Eggs Mean Thickness', MM SOUTH CAROLINA Deveaux Bank Cape Remain (Marsh Island) 20 18 0,460 ± 0,011 A = 0.461 It 0.009 A FLORIDA Cocoa Beach (Hall Island) 10 0.482 It 0.019 AB Pinellas (Tarpon Key) 10 0,487 i 0.015 ABC Crane Island 10 0,491 ± 0,009 ABC Port Orange 9 0,497 iz 0.009 ABCD Pelican Island 9 0.498 ± 0.017 A BCD Cortez 10 0.502 It 0.012 BCD Matlacha Pass 10 0.504 ± 0.019 BCD Fort Pierce 9 0.504 It 0,009 BCD Boca Grande Pass (Bird Key) 10 0.517 It 0.014 BCD Hemp Island 10 0.519 ± 0.015 BCD Fanny Key 7 0.523 ± 0.019 BCD Cedar Key (Seahorse Key) 10 0.531 It 0.016 CD Nest Key 10 0.532 ± 0.012 CD Marquesas Key 10 0.541 It 0.012 D Buchanan Key 10 0.545 ± 0.013 D ' Mean ± standard error. = A significant difference (P<0.05) among thickness means is indi- cated for those means not sharing a common letter. Means were sepa- rated using Duncan's New Multiple Range Test with Kramer's exten- sion for unequal replication. (See footnote 2, Table 2.) TABLE 10. — Reproductive success of brown pelicans in South Carolina. 1969-70 Year 1969 Colony Cape Romain Deveaux Bank Totals or mean 1970 Cape Romain Deveaux Bank Totals or mean Number of Nests 1016 250 637 479 1116 Number of Young Fledged 900 80 980 500 445 Young Fledged PER Nest 0.82 0.32 0.78 0.78 0.93 0.85 TABLE U. — Islands used for nesting by the brown pelican in South Carolina TABLE 8. — Thicknesses of brown pelican eggshells, com- parisons of pre-1947, 1969, and 1970 measurements Mean thickness f standard error Pre-1947 i 1969 1970 SOUTH CAROLINA 0.557 It 0.010 (23) A =| 0.463 ± 0.006 (49) B | 0.461 ± 0.007 (38) B FLORIDA 0.557 ± 0.003 (172) A 0.515 ± 0.005 (81) B 0.512 It 0.004 (144) B ' Sample size in parentheses. - A significant difference (P<0.05) among thickness means for each state is indicated for those means not sharing a common letter. Means were separated using Duncan's New Multiple Range Test with Kramer's extension for unequal replication. (See footnote 2. Table 2.) 194 Island Year Unidentified, Georgetown County 19341 Raccoon Key (Sandy Point) 1931 =; 1943-1946; 1952 :> Cape Island 1939-1942 •' White Banks 1956; 1958-1960; 1963; 1965 = Marsh Island (Vessel Reef) 1947-1948; 1951; 1955-1959; 1962; 1964-1965; 1967 through 1972 » Bird Bank 1901; 1915'; 1926*; 1928=; 1951; 1957-1961; 1963; 1965-1966 •' Unidentified, on beach near Charleston 1901 1 Bird Key (mouth of Stono River) Unknown = Deveaux Bank 1947 through 1972 » Egg Bank (near Beaufort, also called 1904*; 1943' Bird Bank) Unidentified, 18 mi. east of Beaufort 19431 Bay Point (large colony) 1901 ' Anderson and Hickey (see LITERATURE CITED, reference 1). E. Milby Burton (personal communication). Records of the Cape Romain National Wildlife Refuge. I (L.J.B.) have visited the Marsh Island colony each year since 1969. Data taken from egg collection in Charleston Museum. Robert Gracy (personal communication: people associated with this area informed him that pelicans once nested here). Beckett (see LITER.\TURE CITED, reference 2). I (L.J.B.) visited this colony each year since 1969. Pesticides Monitoring Journal Residues of Organochlorine Pesticides, Mercury, and PCB's in Mourning Doves from Eastern United States — 1970-71 J. F. Kreitzer' ABSTRACT Mourning clove (Zenaidura macroura) breast muscle samples from birds collected in } 970-7 1 from Rhode Island, Pennsyl- vania, Maryland, Missouri, Kentucky, Virginia, Arkansas, Tennessee, North Carolina, South Carolina, Mississippi. Alabama, Georgia, Louisiana, and Florida were found to contain residues of DDT, DDE, DDD, polychlorinated bi- phenyls, dieldrin, mirex, mercury, and heptachlor epoxide in amounts not considered hazardous to consumers, human or nonhuman. There were 145 birds involved, 7 to 10 from each State. Residues of DDT plus DDE plus DDD averaged 5.83 ppm lipid weight (0.068 ppm wet weight): those of PCB's, 9.75 ppm lipid weight (0.121 ppm wet weight): com- pounds were found in all birds. Heptachlor epoxide ami dieldrin were found in little more than trace amounts: hepta- chlor in all birds, dieldrin in 73. Mirex was found only in birds from South Carolina, Georgia, and Florida, averaging 4.32 ppm lipid weight (0.046 ppm wet weight) in eight birds. Less than 0.05 ppm (wet weight) mercury was found in all birds except 10, in which it ranged from 0.07 to 0.67 ppm. The 10 were from Rhode Island. Pennsylvania, Marylaiul, Virginia, Tennessee, and Alabama. Introduction This paper reports the residues of organochlorine pesti- cides, polychlorinated biphenyls, and mercury in mourn- ing doves (Zenaidura macroura) of the eastern United States. The study was undertaken to determine whether the small but steady decline of mourning dove popula- tions in the United States during 1960-1970 (Migratory Bird Populations Station, unpublished data) might be related to environmental contaminants, and whether the level of these contaminants in the tissues need cause concern for their consumption as human food. ' Paluxent Wildlife Research Center, Division of Wildlife Research, Bureau of Sport Fisheries and Wildlife, U.S. Department of the Interior, Washington, D.C. 20240. Vol. 7, No. 3/4, March 1974 Certain game birds have been found to contain undesir- ably high levels of toxicants. For example, 28 of 32 pheasants (Phasianus colchicus) found dead or dying in Sweden, 1957-1963. contained between 25 and 140 ppm mercury in liver and kidney tissues, and 16 of 27 pheasants shot or trapped during the same period con- tained more than 1 ppm (range: 1-20 ppm) (7). In 1970, the Canadian government closed the hunting season for woodcock (Philohela minor) in New Bruns- wick because of an average level of 56 ppm DDT (lipid basis) in representative samples taken throughout the Province. In 1969, the Province of Alberta closed the .seasons for pheasant (Phasianus colchicus) and Hungarian partridge (Perdix perdix) because of high levels of mercury in the liver; residues averaged 2.8 ppm in pheasants and 1.1 ppm in partridges (2). Although the season was not closed for sharp-tailed grouse (Pedio- ecetes phasianelhis), concentrations of mercury in the liver were as high as 1.1 ppm. In western Montana 73 samples of fatty tissues from 69 blue grouse (Dendragapus obscurus), collected Vi to 685 days after their range had been sprayed with DDT at Vz lb/ acre, contained DDT-derived residues ranging from 0.9 to 280 ppm (3). In this instance the U.S. DHEW Food and Drug Administration recommended that persons eating game from pesticide-treated areas be warned to trim away fat to the extent practical and thereby reduce exposure to such residues. Materials and Methods Birds were collected from all States east of the Missis- sippi that permit the hunting of mourning doves, except for Illinois, Delaware, and West Virginia. Eastern samples came from Rhode Island, Pennsylvania, Mary- 195 land, Kentucky, Tennessee, Virginia, North Carolina, South Carolina, Mississippi, Alabama, Georgia, and Florida. Three dove-hunting states west of the Missis- sippi were also included; Missouri, Arkansas, and Louisiana. Ten birds were taken from each State except for Arkansas and Virginia which produced nine each, and Pennsylvania, which produced seven. Thus 145 birds were available for tissue analysis. Carcasses were frozen at the time of collection. At preparation of the samples they were partly thawed and a 10-g sample of breast muscle was taken from each. Samples were placed in a glass jar that had been cleaned with nitric acid, acetone, and hexane; then they were re frozen. Analyses were made at WARF Institute, Inc., Madison. Wisconsin, by the following methods; For organochlorines and PCB's, samples were weighed, dried at 40°C for 72-96 hours, reweighed, then ground with sodium sulfate and extracted with petroleum ether:ethyl ether (170 ml:70 ml) on a Soxhlet extractor for 8 hours. They were cleaned and separated into two fractions by passage through a Florisil Column (petro- leum ether;ethyl ether. 95:5, 85:15). An aliquot of the sample was passed through a standardized silicic acid- celite column, with typical elutions of 260 ml petroleum ether:210 ml 1:19:80 acetonitrile:hexane:dichlorometh- ane. Analysis was by a Barber-Coleman Pesticide Analyzer Model 5360. The column was glass, 4 ft by 4 mm, packed with 5% DC-200°C (column), and 240°C (detector); carrier gas was nitrogen at a flow rate that eluted p.p'-DDT in 6-8 minutes. Lipid weight was de- termined from an aliquot of the extract which was re- duced to dryness on a stream bath and placed in a 40°C oven for 2 to 4 hours before weighing. Three- column confirmations of compounds found were made on a random selection of tissue samples. Total mercury was determined by cold vapor atomic absorption. A 10-g portion was digested by refluxing with sulfuric nitric acid mixture (4). A mixture of hydroxy- lamine, stannous chloride, and sulfuric acid was added to the digest to reduce the mercury (II) ions to mercury metal. The sample was aerated (3 liters/min) and passed through the absorption cell. Recoveries of organochlorine pesticides from spiked samples were 75-105%: those of PCB's (based on Aroclor 1254) were 60-85%; and those of mercury were 95%. Residues were not corrected for recovery. The limit of sensitivity was from 0.001 to 0.006 ppm for organochlorines, and 0.05 ppm for mercury. Analyses of variance were made using log transforma- tions. 196 Results and Discussion Results of analyses are in Tables 1 and 1 A. Means given in the tables and in the text are arithmetic. Locations of collection sites with corresponding concentrations of DDE and PCB in the birds are shown in Figures 1 and Because of the low residues in many samples and the numerous "less than" values, overall means were com- puted only for DDT and its metabolites (DDE and DDD), mirex, and PCB's. Means were; 5.83 ppm lipid weight (0.068 ppm wet weight) DDT (including metab- olites); 4.32 ppm lipid weight (0.046 ppm wet weight) mirex; and 9.75 ppm lipid weight (0.121 ppm wet weight) PCB's. Statistical comparisons were possible only for DDE and PCB's (Table 2). These comparisons are strictly between collecting sites, not between states: the sites were not selected at random. There were no clearcut differences between northern sites and southern sites or between other geographical regions. Mercury was found in small amounts, less than 0.05 ppm (wet weight) except in 10 birds in which it ranged from 0.07 to 0.67 ppm. The 10 were from Pennsylvania, Rhode Island. Maryland, Alabama, Tennessee and Vir- ginia. Heptachlor epoxide and dieldrin were found in little more than trace amounts in most birds; only a few birds contained more than 1 ppm. Amounts of heptachlor epoxide ranged from 0.14 to 8.70 ppm lipid weight (<0.006 to 0.170 ppm wet weight), and those of dieldrin, from 0.11 to 10.22 ppm lipid weight (0.001 to 0.160 ppm wet weight). DDT and its metabolites, PCB's, heptachlor epoxide, and mercury were found in all birds; dieldrin was found in 73; and mirex in 8. The relatively small amounts of these compounds in the birds suggest there is little hazard, if any, to the birds themselves, or to the consumers, human or nonhuman, of the birds flesh. The amount of DDT and its metab- olites does approach the amount of DDT permitted in ground beef by Federal regulations (7 ppm in the fat). But since dove meat has so little fat (1.3% in the tissues analyzed), an individual would have to eat nearly 26 pounds of it to ingest the amount of the pesticide per- mitted in 1 pound of hamburger. About 550 doves would be required. LITERATURE CITED (/) Hoif;. A... //. Wanlorp, K. Erne, iiiul E. Hanko. 1969. Alkyl mercury poisoning in Swedish wildlife. Viltrevy 6(4): 301-379. (2) Fimreite, N., R. W. Fyfe, and J. A. Keith. 1970. Mer- cury contamination of Canadian prairie seed-eaters and Pesticides Monitoring Journal their avian predators. Can. Field Natur. 84(3): 269-276. (3) Mussehl. T. W., and R. B. Finley, Jr. 1967. Residues of DDT in forest grouse following spruce budworm spray- ing. J. Wild!. Manage. 31(2): 270-287. (4) Monk, H. E. {Chairman), J. A. Pickard, N. A. Smart, \ fJu^r^^^ ^^\ A r%? V' i 28 \r\ h \ ~\ 3.5 *\i 1.1 G. \ TTv/ \ 31 / 10 7 • /m-„ ■ A,. \ 1 L, IW' HT I 4 2\ FIGURE 1. — Mean (geometric) concentration of DDE (lipid basis) in breast mitscle of mourning doves, 1970-7 P S. H. Yuen. E. W. Atkins, A. S. Beidas, T. E. Burke, H. Cros.tley, H. Egan. P. W. Lloyd, and E. J. Miller. 1961. Recommended methods of analysis of pesticide residues in foodstuffs. Report by the Joint Mercury Residues Panel. Analyst 86: 608-614. 1 ^^*v^^ ?M ' 13.8 \ r-\ \ 115*W 7 68/ ■ A,. \ G.'\ 5- vy |i 7 5 1 8 3\ FIGURE 2. — Mean (geometric) concentration of PCB (lipid basis) in breast muscle of mourning doves, 1970-71' Dots show approximale sites of collection. Dots show approximate sites of collection. TABLE 1. — Residues of DDE, DDD, and DDT in breast muscle of mourning doves from 15 eastern hunting states, 1970-71 No. OF Birds at Residues, ppm Collection Site DDE DDD DDT Low High Mean Low High Mean Low High Mean Rhode Island w 0.010 0.160 0.050 < 0.006 0.034 0.008 <0.006 0.008 0.006 (Washington Co.) L 0.550 9.898 3.072 <0.168 2.774 0.522 <0.144 0.561 0.351 Pennsylvania 7 W 0.006 0,440 0.084 < 0.006 0.009 0.006 < 0.006 0.011 0.006 (Berks Co.) L 0.411 38.52 6.002 <0.223 0.632 0.412 <0.223 0.632 0.439 Maryland (Anne Arundel Co.) (Prince Georges Co.) 10 W L <0.005 <0.175 0.047 4.338 0.014 0.962 <0.175 <0.938 < 0.006' <0.175 0.938 <0.006* Missouri W 0.021 0.220 0.073 <0.006 0.034 0.013 < 0.006 0.064 0.013 (Cape Girardeau Co.) L 2.555 10.44 4.984 <0.361 2.446 0.865 <0.400 3.218 0.871 Kentucky 10 W <0.006 0.024 0.013 - - < 0.006* - — < 0.006* (Trigg Co.) 1. 0.366 1 .275 0.864 <0.235 < 0.463 - <0.235 < 0.463 - Virginia 9 W < 0.006 0.071 0.015 - - <0.006* - - < 0.006* (Montgomery Co.) L 0.273 7.350 1.466 0.273 < 0.674 < 0.273 <0.899 — Vol. 7, No. 3/4, March 1974 197 TABLE 1. — Residues of DDE, DDD, and DDT in breast muscle of mourning doves from 15 eastern liunting states, 1970-71 — Continued No. OF Birds < a Residues, ppm DDE DDD DDT Collection Site Low High Mean Low High Mean Low High Mean Arkansas 9 W 0.006 0.065 0.019 — — < 0.006' — — <0.006* (Conway Co.) L 0.541 6.140 1.730 < 0.226 <0.682 — <0.226 <0.682 - Tennessee 10 W 0.005 0.085 0.023 <0.006 0.008 - < 0.006 0.012 - (Stewart Co.) L 0.417 8.468 1.777 < 0.254 0.811 - <0.254 1.261 - North Carolina 10 W 0.006 0.039 0.014 — - <0.006* — - <0.006» (Wake Co.) L 0.471 2.953 1.088 <0.258 <0.531 — <0.258 <0.531 — South Carolina 10 W 0.009 0.580 0.026 <0.006 0.024 0.010 < 0.006 0.018 0.008 (Charleston Co.) L 0.806 76.118 7.739 <0.302 3.176 1.020 <0.352 2.471 0.754 Mississippi 10 W 0.009 0.270 0.087 <0.006 0.046 0.012 < 0.006 0.063 0.013 (Madison Co.) L 0.559 26.415 7.724 <0.373 4.528 1.132 <0.132 6.226 1.219 Alabama (Chocktaw Co.) (Mobile Co.) 10 W L 0.007 0.389 0.810 78.00 0.126 11.490 <0.006 <0.333 0.013 1.181 0.008 0.628 < 0.006 <0.333 0.044 2.835 0.014 1.182 Georgia (Oconee Co.) (Toombs Co.) 10 W L 0.008 0,678 0.400 35.60 0.122 9.379 < 0.006 <0.339 0.050 3.670 0.016 1.231 <0.006 <0.339 0.008 3.511 0.006 1.234 Louisiana 10 W < 0.003 0.013 0.008 — <0.007 — — <0.007 — (Terrebonne Co. ) L <0.220 2.368 1.064 <0.330 <0.882 — <0.330 <0.882 — Florida 10 W 0.010 0.250 0.089 <0.006 0.032 0.008 <0.006 0.150 0.008 (Highland Co.) L 0.991 25.69 7.756 <0.444 3.303 0.732 <0.380 1.193 0,663 W = wet weight; L = lipid weight. * = All birds reported at this value. ND = Not detected; value = 0 in computing means. Numerals in parentheses indicate number of birds in which the compound was not detected. < quantities taken at face value in computing means. Means are arithmetic. TABLE I A. — Residues of PCB's, diehirin. miiex, and heptachlor epoxide in breast muscle of mourning doves from 15 eastern hunting states, 1970-71 No. < Residues, ppm Collection PCB DlELDR N MiREX Heptachlor epoxide OF :S Site Birds Low High Mean Low High Mean Low High Mean Low High Mean Rhode Island 10 W 0.091 0.520 <0.229 <0.005 0.160 — ND <0.006 0.170 -(5) (Washington Co.) L 8.867 43.307 14.131 < 0.566 10,22 — <0.143 7.936 — (5) Pennsylvania 7 W 0.072 0.140 0.102 <0.005 0.016 — ND < 0.006 0.021 -(2) (Berks Co.) L 3.234 9.895 7.027 <0.526 1.012 — < 0.223 1.310 — (2) Maryland W 0.046 0.180 0.088 __ _ 0.005*(8) <0.006* (Anne Arundel Co.) 10 ND (Prince Georges Co. L 3.179 21.406 5.929 <0.298 <0.781 — <0.I75 0.411 — Missouri 10 W 0.093 0.280 0.153 0.005 0.077 0.016 ND <0.006 0.027 — (1) (Cape Girardeau Co.) L 4.760 31.609 13,320 0.361 2.299 1.083 < 0.361 3.103 — (1) Kentucky 10 W 0.061 0,200 0.118 ND ND - - < 0.006* (TriggsCo.) L 4.573 15.583 8.326 <0.235 < 0.500 — Virginia 9 W 0.110 0.240 0,164 ND ND - - <0.006» (Montgomery Co.) L 8.864 23,810 15.520 < 0.272 < 0.674 — 198 Pesticides Monitoring Journal TABLE lA. — Residues of PCB's, dieldrin, mirex, and heplachlor epoxide in breast muscle of mourning doves from 15 eastern hunting states, 1970-71 — Continued No. OF Birds 1 Residues, ppm PCB Dieldrin Mirex Heptachlor epoxide Collection Site Low High Mean Low High Mean Low High Mean Low High Mean Arkansas (Conway Co.) 9 w L 0.073 3.860 0.170 16,367 0.089 7.201 — 0.006 0.526 -(8) —(8) ND <0.006 <0.382 0.015 1.404 - Tennessee (Stewart Co.) 10 W L 0.075 6.042 0.240 24.234 0.154 12.320 < 0.005 < 0.2 12 0.006 0.631 —(5) —(5) ND <0.254 <0.541 <0.006» North Carolina (Wake Co.) 10 W L 0.042 3.100 0.082 6.351 0.061 4.654 < 0.258 <0.462 <0.005*(8) —(8) ND <0.257 <0.531 <0.005» South Carolina 10 W 0.086 0.160 0.121 <0.005 0.024 —(2) 0.005 0.039 0.007(8) — - <0.006* (Charleston Co.) L 5.324 18.229 12.004 <0.25l 3.012 -(2) 0.602 4.234 2.680(8) < 0.302 < 1.008 — Mississippi (Madison Co.) 10 W L <0.060 3.263 0.660 17.981 0.145 8.044 <0.313 <0.658 <0.005*(5) -(5) ND < 0.006 <0.373 0.015 1.578 — Alabama (Chocktaw Co.) (Mobile Co.) 10 W L 0.033 2.782 0.088 13.048 0.071 6.168 <0.270 <0.400 <0.0O5«(6) —(6) ND <0.006 <0.324 0.091 8.696 — Georgia (Oconee Co.) (Toombs Co.) 10 W L 0.047 3.538 0.170 12.067 0.097 7.426 < 0.249 <0.256 6.005*(8) — (8) < 0.005 <0.282 0.370 25.800 0.124(7) 9.597(7) — 0.455 <0.006* Louisiana (Terrebonne Co.) 10 W L 0.060 6.154 0.220 28.529 0.121 15.853 0.001 0.110 0.002 0.357 0.002 0.225 ND 0.004 0.440 0.010 1.316 0.008 0.967 Florida 10 W 0.055 0.160 0.096 — — <0.0O5'(5) 0.007 0.011 0.008(7) < 0.006 0.008 — (1) (Highland Co.) L 3.924 15.766 8.981 < 0.224 <0.505 —(5) 0.519 0.760 0.687(7) <0.379 0.645 — (1) W = wet weight; L = lipid weight. * = All birds reported at this value. ND = Not detected; value in 0 in computing means. Numerals in parentheses indicate number of birds in which < quantities taken at face value in computing means. Means are arithmetic. the compound was not detected. TABLE 2. — Intersite comparison of means of DDE and PCB (ppm lipid basis) in dove breast muscle, 1970-7 V Site DDE Means County State Arithmetic G BOMETRIC Oconee Ga. Toombs Ga. 9.38 5.45 a Madison Miss. 7.72 4.67 ab Highland Fla 7.76 4.23 ab Chocktaw Ala. Mobile Ala. 11.49 3.95 ab Cape Girardeau Mo. 4.98 3.48 abed Charleston S.C. 7.74 3.12 abed Washington R.L 3.07 2.82 abed Berks Pa. 6.00 1.70 abcde Trigg Ky. 0.90 1.12 bede Stewart Tenn. 1.78 1.07 bede Conway Ark. 1.73 0.96 ede Terebonne La. 1.06 0.91 de Wake N.C. 1.09 0.90 de Anne Arundel Md. Prince Georges Md. 0.96 0.61 e Montgomery Va. 1.47 0.45 e Site PCB Means County State Arithmetic Geometric Terrebonne La. 15.85 18.32 a Washington R.L 14.13 13.76 ab Cape Girardeau Mo. 13.32 11.54 abc Charleston S.C. 12.00 11.48 abc Montgomery Va. 15.52 11.28 abc Stewart Tenn. 12.32 10.84 abc Highland Fla. 8.98 8.33 bed Chocktaw Ala. Mobile Ala. 6.17 8.33 bed Trigg Ky. 8.33 7.86 bed Madison Miss. 8.04 7.48 bed Oconee Ga. Toombs Ga. 7.43 7.09 bed Conway Ark. 7.20 6.80 bed Anne Arundel Md. Price Georges Md. 5.93 6.02 cd Wake N.C. 4.65 4.46 d Becks Pa. 7.03 3.98 d 1 The geometric means of any two sites not followed by the same letter are significantly different (Duncan multiple range test). Vol. 7, No. 3/4, March 1974 199 PESTICIDES IN SOIL DDT Residues in Soil, Water, and Fauna from New York Apple Orchards ' R. J. Kuhrr A. C. Davis,-' and J. B. Bourke' ABSTRACT Five commercial apple orcliaiJs H'liich had not been sprayed extensively with DDT since approximately I960 were sur- veyed in 1972 for residues of DDT and its metabolites. In addition to the parent compound, DDE and DDD were almost always recovered, hut no dicofol was detected in any soil sample. Total residues in the top 6-in. soil layer under- neath the trees ranged from 21.8 to 259 lb/acre. Between the rows of trees the levels were considerably lower: they ranged from 7.3 to 78.5 lb/6-in. acre. In one heavily contaminated orchard, researchers also analyzed stream water, stream- bottom mud, and animals. Very low amounts of DDT (0.32 ppbj and DDD (0.042 pph) were found in the water, and residues in stream-bottom i7uid totaled less than 1 ppm. Worms, slugs, snails, tadpoles, fingerling fish, and frogs all contained DDT, DDE. and DDD. Introduction Residues of DDT and its metabolites persist in many corners of our environment, but one of the largest reservoirs for these chemicals is orchard soil (/). A recent survey which included orchards across the United States revealed a DDT soil load ranging from 0.07 to 245.4 ppm (2). Other, less extensive orchard surveys in the United States, Canada, and Great Britain have indicated residue levels somewhere between these ex- tremes (3-II). In two of these studies, (4. 7). residues of DDT and analogs were also reported for soil insects, slugs, snails, and worms. Most of the animals had ac- cumulated 2 to 4 times as much DDT as was present in their surrounding soil. 1 Approved by the Director of the New York State Agricultural Expe- riment Station as Journal Paper No. 2027. Supported in part by Northeast Regional Research Projects 36 and 53. = Department of Entomology. New York State Agricultural Experiment Station, Geneva, N.Y. 14456. ' Department of Food Science and Technology, New York State Agri- cultural Experiment Station, Geneva. N.Y. 14456. In New York, about 72,000 acres of land are currently devoted to commercial apple orchards. Although most of the orchards have not been treated regularly with DDT for more than 10 years, almost all of them had relied on DDT for insect control from approximately 1947 to 1960. During this time, an acre in a typical commercial apple orchard would have been sprayed with 250-400 lb of DDT. The following study was de- signed to examine how much DDT and metabolites still remained in the soil, how the residue was distributed in the soil, and whether any of the residue had moved into waterways or animal life within the orchard. Material.^ and Methods Five commercial orchards were chosen at random from the heart of New York's apple belt along the southern shore of Lake Ontario, Soil samples were removed from an area near the middle of each orchard. Four of the locations contained trees at least 25 years old, but the trees from orchard G were estimated to be only about 15 years old. Orchard D was sampled in two locations: one at the top of a hill near a stream meandering through the orchard, and the other in a low spot where drainage tile had recently been installed. At each site, four soil cores were removed from under each of six trees in an area about halfway between the trunk and outer branches. An additional 24 cores were taken from the aisles between the rows of trees. No attempt was made to scrape away surface vegetation or decaying plant debris before sampling. This material was included as part of the upper soil layer. Each cylindrical core consisted of three soil plugs I's in. in diameter, 2 in. long, and 4.14 cubic in. in volume. After removal of the 2-in. plug, a second sampler was carefully in- serted into the same hole to get the 2- to 4-in. plug; 200 Pesticides Monitoring Journal the same procedure was repeated for the 4- to 6-in. plug. The 24 plugs from each depth were sealed in a plastic bag until they could be weighed and thoroughly mixed. Only large stones were removed to prevent breakage of glassware during the extraction procedure. Since orchard management (cultivation, vegetative cover, etc.) and soil type and texture varied, it was decided to use unscreened wet soil directly from the orchard and to convert all results to lb residue/ 2-in. acre for com- parative purposes. Two 100-g subsamples from each bag of soil were weighed separately into 1 -liter flasks. Enough water (^40 ml) was added to each flask to make a slurry; into the slurry was poured 600 ml of 3:1 petroleum ether: isopropanol. The flask was placed on a wrist-action shaker and thoroughly agitated for 5 min. After separa- tion, the solvent layer was decanted into a 1 -liter separatory funnel and the alcohol was removed with three 150-mI washes of water. The remaining petroleum ether extract was dried over anhydrous sodium sulfate and a portion was injected directly into an Aerograph Hy-Fi Model 550-B gas chromatograph equipped with an electron-capture detector and a 3-ft-by-'/8-in-column containing 5% Dow 11 on 60-80 Gas Chrom-Q at a temperature of 195°C. Recovery from DDT-spiked soil samples averaged 95% and method sensitivity allowed for detection levels above 0.13 lb 2-in. acre. Several other extraction procedures were tried, but none re- moved more residues than did the method described above. There were no chemicals extracted from the soil which interfered with DDT and DDT-analog peaks from the gas chromatograph. Reported values for soil residues have not been corrected for recevorey and represent an average of the two subsamples. On several occasions, two 1-gaI. water samples and two 1-qt bottom mud samples were taken from the stream in orchard D at four different locations. Additional samples were removed from a small bay in the stream where spray tanks were filled and from the end of a drainage tile where it emptied into the stream. The mud samples were extracted as described for soil except that the petroleum ether extract was concentrated before gas chromatography (95% recovery, 0.005 ppm sensi- tivity limit). Each gallon of water was distributed equally between three 2-liter separatory funnels. To the first funnel was added 150 ml of petroleum ether. After thorough mixing and separation of layers, the petroleum ether was drawn off and transferred to the second funnel. Following extraction of this water, the process was repeated on the third funnel. The entire procedure was reenacted two more times, changing only the se- quence of funnels. The combined petroleum ether ex- tracts were dried with anhydrous sodium sulfate and con- centrated before gas chromatographic analysis. Spiked recoveries averaged over 98% and method sensitivity was 0.13 ppb. Orchard D was also the site of animal collections. Worms were obtained by digging soil and turning over surface debris under and between rows of trees in the area where soil samples were removed. Most of the slugs were captured under trees near the stream. Frogs, tadpoles, fingerling fish, and snails were scooped from the stream with a long-handled net. All specimens were brought back to the laboratory where they were washed, weighed, and immediately frozen. This procedure was repeated on two separate occasions, producing a total sample weight of 36.6 g worms, 6.1 g slugs, 107 g frogs, 23.4 g tadpoles, 7.7 g fish, and 11.0 g snails. Each collection was analyzed separately, and results were averaged for the two corresponding samples. Residues were determined after the animals had been freeze- dried and extracted according to the method of Harence et al. (12). The final hexane extract was analyzed by gas chromatography as described for soil samples. Re- covery from spiked tissues averaged 78% and reported values have been corrected to 100%. Results and Discussion All soil samples removed from the orchards contained measurable amounts of DDT and DDE; many samples also contained DDD. Although the analysis procedure allowed for detection of dicofol, which has been dis- covered in other orchard soil (8-10), this DDT metab- olite was not picked up in any of the test orchards. The total load of DDT, DDE. and DDD in the top 6 in. of soil and vegetation varied considerably from a high of 258.8 lb/ acre under the trees in orchard D to a low of 7.3 lb/acre between the rows of trees in orchard G (Table 1 ). It is difficult to explain this broad range because the complete spray history of each orchard is unknown. Except for orchard G, the orchards were sampled in areas which had probably been exposed to regular DDT treatments for more than 10 years. Un- doubtedly, some of the variation was due to differences in soil type, soil structure, chemical makeup, physical conditions, and cultivation practices. However, only a very small portion of the residues are probably due to the DDT spray used occasionally after 1960 because the total application during this period probably did not amount to more than 2-3 lb/ acre. Based on previous studies, the horizontal and vertical distribution of residues within the soil was not surprising. For example, more residues were located under the trees than between the rows of trees (Table 1 ). This has been an almost universal finding in orchard surveys (5. 6. 9, 13, 14). With the exception of the tiled region between the trees of orchard D, there was a general trend of decreasing contamination with increasing soil depth. A change in residue profile for the tiled region was probably due to the turnover and mixing of soil that occurred when the drainage system was installed. In highly contaminated orchards (D-Hill, C, and P), Vol. 7, No. 3/4, March 1974 201 75-85% of the total residue still remained in the top 2-in. layer. In the other orchards these values were inclusive for the upper 4 in. of soil. Previous orchard surveys which probed deeper than 6 in. have yielded similar results (6, 10, 14), although in these instances samples were taken during or shortly after DDT treat- ment. The results in Table 1, obtained from orchards that had not been sprayed regularly with DDT for ap- proximately 13 years, indicate that there has been very little downward movement of DDT during this time. If the total residue distribution is broken down into individual compounds, an interesting consistent observa- tion can be made. At almost every site, the percentage of the total 6-in. residue found in the top 2 in. of soil was nearly the same for DDT and DDE. On the other hand, where DDD was present, its distribution within the top 2 of 6 in. was almost always relatively higher. This higher soil load of DDD in the upper layer is probably due, in part, to several factors. First, during the time of DDT usage, most orchard owners applied some DDD (Rhothane) to control red-banded leaf rollers: infestations of this insect varied greatly from season to season and from orchard to orchard, and the use of DDD varied accordingly. The initial deposition of DDD may have migrated more slowly down into the 4- and 6-in. soil layers than did the DDT. Secondly, microorganisms in the decaying vegetation present in the top soil layer may have converted more DDT to DDD. Orchard sites which contained no detectable levels of DDD could have experienced a minimum amount of DDT-to-DDD conversion in the soil, coupled with a minimum application of DDD. Of the total residue located in all the orchards at every soil depth, 70-90% persisted as DDT. With some ex- ceptions, the remainder was divided between DDE and DDD so that DDE levels were always approximately equal to or greater than DDD levels. This distribution fits a pattern that seems common to many orchards (5. S-10. 15). Turning to the animal life collected from orchard D, it is apparent that residues of DDT, DDE, and DDD were present in every species captured (Table 2). Worms and slugs which were in direct contact with the heavily TABLE 1. — Residues of DDT, DDD. and DDE in soil from five New York apple orchards Residues Expressed as lb/2-in. Acre • Soil Level, IN. Under Trees Between Rows of Trees DDT DDD DDE Total DDT DDD DDE Total ORCHARD D, TILED REGION 0-2 152.0 8.9 14.4 175.3 16.4 4.2 2.1 22.7 2-4 38.3 0.3 4.5 43.1 16.2 0.9 3.4 20.5 4-6 35.7 0.7 4.0 40.4 24.0 4.9 6.4 35.3 0-6 226.0 9.9 22.9 258.8 56.6 10.0 11.9 78.5 ORCHARD D. HILL REGION 0-2 162.0 14.4 12.3 188.7 40.9 3.0 6.7 50.6 2-4 27.5 1.1 3.4 32.0 6.5 0.3 1.4 8.2 4-6 13.7 1.5 1.9 17.1 3.0 0.1 0.4 3.5 0-6 203.2 17.0 17.6 237.8 50.4 3.4 8.5 62.3 ORCHARD C 0-2 135.0 19.5 9.7 164.2 42.7 8.5 10.2 61.4 2-4 15.8 0.5 1.4 17.7 9.1 1.2 2.0 12.3 4-6 9.1 0.0 1.1 10.2 2.5 0.0 0.7 3.2 0-6 159.9 20.0 12.2 192.1 54.3 9.7 12.9 76.9 ORCHARD P 0-2 40.6 0.0 9.4 50.0 22.7 0.0 8.8 31.5 2-4 17,4 0.0 5,0 22.4 5.5 0.0 2.3 7.8 4-6 15.2 0.0 2.6 17.8 1.8 0.0 0.6 2.4 0-6 73.2 0.0 17.0 90.2 30.0 0.0 11.7 41.7 ORCHARD Y 0-2 17.4 3.0 4.4 24.8 8.2 0.0 3.8 12.0 2-4 10,0 1.2 3.1 14.3 10.6 0.0 4.1 14.7 4-6 5.8 0.0 1.6 7.4 4.0 0.0 1.8 5.8 0-6 33.2 4.2 9.1 46.5 22.8 0.0 9.7 32.5 ORCHARD G 0-2 8.4 0.6 1.6 10.6 3.2 0.0 0.7 3.9 2-4 6.1 0.0 1,1 7.2 1.4 0.0 0.6 2.0 4-6 3.6 0.0 0.4 4.0 0.9 0.0 0.5 1.4 0-6 18.1 0.6 3.1 21.8 5.5 0.0 1.8 7.3 ' To convert values for individual 2-in. soil layers to approximate ppm wet weight, multiply by 1.5. 202 Pesticides Monitoring Journal TABLE 2.— Residues of DDT, DDD, and DDE in animals collected from Orchard D Residues in ppm Based on Wet-weioht Residues in ppm Based on Dry-weiokt Animal DDT DDD DDE Total DDT DDD DDE Total Earthworm Slug Frog Tadpole Fish Snail 21.7 5.6 2.8 1.7 0.5 0.8 4.0 5.2 1.8 1.0 0.5 0.5 5.1 2.6 2.2 0.6 0.6 0.3 30.8 13.4 6.8 3.3 1.6 1.6 106 28.1 13.3 16.5 3.1 1.8 17.6 23.9 10,0 9.0 3.0 1.5 24.0 12.1 10.9 5.1 3.8 0.7 147.6 64.1 34.2 30.6 9.9 4.0 contaminated soil in the hill region of orchard D contained the largest quantities of residues on a wet- weight basis. However, the amounts did not approach those found in the upper 6 in. of soil. Other studies have shown that worm and slug residues were considerably higher than surrounding soil residues (4, 7), although in such instances the soil load was much less than that of orchard D. Fittingly, an intermediate contamination level was found in frogs. These animals were exposed to residues on land and in the orchard's small stream. Finally, finger- ling fish, tadpoles, and snails contained relatively small quantities of DDT, DDE, and DDD. Unlike the land inhabitants, however, the stream dwellers obviously were capable of concentrating residues from their sur- roundings. Although none of the water collected con- tained measurable amounts of DDE, an average of 0.32 ppb of DDT and 0.042 ppb of DDD was found in stream samples. Contamination was slightly higher in water collected from the stream bay and the drainage tile. The increase in the tile water may have resulted from its intimate contact with soil residues as it per- colated slowly through the soil column. Interestingly, there was a general increase in the quantity of residues present in water as the season progressed from early spring to early fall. There are several possible reasons for this: e.g., changes in flow rate, volume of flow, con- tribution from ground water. Contamination of the mud below the stream was considerably higher than that in the water; average residues were 0.08 ppm DDT, 0.06 ppm DDE, and 0.12 ppm DDD. This very low presence of DDT and analogs in water and their concentration in bottom mud and aquatic animal life has been well documented by other studies (/). One noticeable difference between soil residues and animal residues was in the respective amounts of DDT and its degradation products. Only 30-50% of the total contamination in animals was due to DDT itself; in soil, the parent compound represented 70-90% of the total residue. The larger proportion of DDE and DDD in animals was probably due to an increase in DDT metabolism by the animals. Other investigations have shown that plants grown on DDT-rich soil tend to accumulate DDT residues, al- though not to the extent of animal life (/). A small sample of dandelions was removed from under the trees of orchard D and thoroughly washed with distilled water. Following aqueous homogenization of a 100-g sample, the plants were extracted and analyzed using the same method described for soil samples. Residues on a wet-weight basis were 4.2 ppm DDT, 2.6 ppm DDD, and 0.86 ppm DDE. Conclusions Despite the fact that commercial apple orchards in upstate New York have not received regular DDT treatments for about 13 years, their soil is still con- taminated with DDT and some of its metabolites. Quali- tative estimates and calculated guesswork indicate that, in one particular orchard, approximately half the DDT applied from 1947 to 1960 continues to persist in the soil as DDT, DDD, and DDE. However, results suggest that other orchard soils contain considerably less ma- terial even though they were probably all originally exposed to similar spray schedules. Within one heavily residued orchard, DDT and analogs were detected in all animal species captured and in a small sample of growing vegetation. Many of these animals had been removed from a stream which trickled through the heart of the orchard. Samples of stream water and bottom mud contained minute quantities of DDT residues, implying that movement of the in- secticide from the soil into the waterway was not exces- sive. In fact, the low levels present in the stream en- vironment coupled with the high soil load suggests that the DDT residues are present in a relatively static situation, moved about primarily by animal life and redistributed principally as part of a mobile food chain. A cknowledgments The authors thank P. I. Chapman, E. H. Glass, S. E. Lienk, and K. Trammel for suggestions and information; M. E. Bennet, H. L. Eshenour, S. Gibbons, and J. L. Schohn for assistance in sample collection and extrac- tion; and R. G. Clark, S. Gibbs, and R. Marafioti for analysis of the extracts. Vol. 7, No. 3/4, March 1974 203 LITERATURE CITED (1) Edwards, C. A. 1970. Persistent pesticides in the en- vironment. The Chemical Rubber Co., Cleveland, Ohio. 78 pp. (2) Stevens, L. J., C. W. Colier, and D. W. Woodham. 1970. Monitoring pesticides in soils from areas of reg- ular, limited, and no pesticide use. Pestic. Monit. J. 4: 145-166. (i) Chisholm. R. D.. L. Koblilsky. J. E. Fahey, and W . E. Wesllake. 1950. DDT residues in soil. J. Econ. Entomol. 43: 941-942. {4) Davis, B. N. K. 1968. The soil macrofauna and organo- chlorine insecticide residues at twelve agricultural sites near Huntingdon. Ann. Appl. Biol. 61: 29-45. (J) Duffy, J. R., and N. Wong. 1967. Residues of organo- chlorine insecticides and their metabolites in soils in Atlantic Provinces of Canada. J. Agr. Food Chem. 15: 457-464. (6) Ginsbuig, J. M.. and J. P. Reed. 1954. A stirvey of DDT-accumulation in soils in relation to different crops. J. Econ. Entomol. 47: 467-474. (7) Gisti, G. D. 1970. Organochlorine insecticide residues in soils and soil invertebrates from agricultural lands. Pestic. Monit. J. 3:241-252. (S) Harris, C. R.. and W. W. Sans. 1971. Insecticide resi- dues in soils on 16 farms in Southwestern Ontario — 1964, 1966, 1969. Pestic. Monit. J. 5: 259-267. (9) Harris. C. R., W. W. Sans, and J. R. W. Miles. 1966. Exploratory studies on occurrence of organochlorine insecticide residues in agricultural soils in Southwestern Ontario. J. Agr. Food Chem. 14: 398-403. (10) Kiigemagi. V., and L. C. Terriere. 1972. Persistence of DDT in orchard soils. Bull. Environ. Contam. Toxicol. 7: 348-352. (//) Lichtcnstein, E. P. 1957. DDT accumulation in mid- western orchard and crop soils treated since 1945. J. Econ. Entomol. 50: 545-547. {12) Harence. J. H.. P. S. 'Hall, and D. J. Caverly. 1965. The identification and determination of chlorinated pesticide residues. Analyst 90: 649-656. (/_?) Ginshnrg, J. M. 1955. Accumulation of DDT in soils from spray practices. J. Agr. Food Chem. 3: 322-325. {14) Heme, D. C, and D. Chisholm. 1958. Accumulation of DDT in the soil of an Ontario peach orchard. Can. J. Soil Sci. 38: 23-26. (15) Davis, B. N. K., and R. B. Harrison. 1966. Organochlo- rine insecticide residues in soil invertebrates. Nature 211: 1424-1425. 204 Pesticides Monitoring Journal GENERAL Chlorinated Insecticide Residues in Kentucky Burley Tobacco: Crop Years 1963-72 ' James R. Gibson,' George A. Jones,' H. Wyman Doroiigh,'" Christina I. Liislc ,' and Richard Thurston' ABSTRACT Kentucky Burley tobacco representing crop years 1963-70 was sampled from the storage facilities of the Burley To- bacco Growers Cooperative Association and from auction warehouses in Kentucky in 1968-72. Analyses of these samples in 1972 showed 100% contained DDT-TDE: 96%, dieldrin; 31%, endrin: and 4%, toxaphcne. Endosulfan res- idues were first detected in a few samples of the 1968 tobacco but were present in 100% of the 1970 and 1972 tobacco, and in 83%> of the 1971 crop. Average total chlorinated insecticide residues in tobacco produced during 1963-65 were approximately 20 ppni, and for that produced during 1966-69, levels were about 50 ppm. Levels dropped markedly in 1970 to 12 ppm, declined to 9 ppm in 1971, and then to 4 ppm in 1972. During the years when residues were highest, DDT-TDE constituted over 90% of the total, but declined so rapidly after 1968 that they accounted for only 8% of the total chlorinated insecticide residues in the 1972 tobacco; 90% of the residues on the 1972 tobacco was endosulfan. The relationships of area and year of production to the levels of chlorinated insecticide residues on Burley tobacco are discussed. Iiilrdduclion As of this printing, no official pesticide tolerances on tobacco have been established by the U.S. Government. Whether this situation will change is uncertain. How- ever, it is likely that some action will be taken to control the levels of pesticides on future tobacco crops, either by establishing tolerances or by limiting the kinds and/ or amounts of chemicals which may be used. The latter control already applies to DDT and TDE; their registra- ^ Department of Entomology, University of Kentucky, Lexington, Ky. 40506. This study was supported in part from funds from the Tobacco and Heahh Research Institute (Project KTRB 040) and from Re- gional Research Project S-73. - To whom cor'-espondence should be addressed. Vol. 7, No. 3/4, March 1974 tion for use on tobacco was cancelled prior to the 1970 growing season. The future of pesticide tolerances on tobacco may be elucidated to some degree by examining recent action of the West German Government (/). Legislation is pend- ing which would place tolerances on approximately 80 different pesticides used on tobacco. Certain chemicals, including the chlorinated insecticides dieldrin, endrin, chlordane, and heptachlor, could not be present at any level, and thus could not be used in any manner for the control of tobacco pests. Other residues would be al- lowed at low levels, as exist in general environmental contamination, for example. But the acceptable quanti- ties are so low that their use as a pesticide on tobacco probably would be prohibited. Examples of common chlorinated insecticides and their proposed tolerances are DDT-TDE and analogs, O.I ppm; toxaphene, O.I ppm; and endosulfan, 0.5 ppm. For most other insecticides commonly used on tobacco the tolerances are usually below 1.0 ppm. However, the tolerance for carbaryl, a carbamate, is 2.5 ppm and for malathion, an organophosphorus compound, it is 3.0 ppm. Although the legislation has not been passed by the West German Government it is quite possible that the final tolerances will remain just this stringent. Much of the tobacco produced in the United States contains levels of pesticide residues which would not conform to the pending regulations mentioned above. Several studies (2, 3, 4) have shown that tobacco of com- merical cigarettes contains residues of chlorinated in- secticides much greater than the tolerances proposed in West Germany. A comprehensive study of the chlorinated insecticide content of Kentucky Burley tobacco has not been made; 205 its contribution to the residue levels in United States tobacco products is not known. The current study was conducted to determine the levels of chlorinated in- secticides in Kentucky Burley tobacco produced in previous years but still available for sale, and to evaluate the effect of changing insecticide use on the levels and kinds of insecticides in tobacco. These factors were studied in relation to grades of tobacco and to areas in which the tobacco was grown. Methods and Materials Burley tobacco samples were collected from tobacco held in storage by the Burley Tobacco Growers Co- operative Association (Burley Tobacco Pool) and from auction warehouses in Kentucky. Tobacco in the Burley Tobacco Pool represents many crop years since it is purchased annually by the Federal Government as part of the U.S. Department of Agriculture price con- trol program. This tobacco, still for sale, is stored at various locations in Kentucky and the storage site gen- erally contains crops produced only in that area. It was possible, then, to compare residue levels with the loca- tion of crop production for 1963 through 1970, those crop years for which tobacco was available from the Burley Tobacco Pool. This was evaluated in greater detail in studies in which Burley tobacco was taken from the auction markets at the end of the growing seasons in 1968 through 1972. SAMPLING Burley Tobacco Pool Tobacco stored in the Burley Tobacco Pool is in the hand form contained in a hogshead filled with ap- proximately 1000 pounds of tobacco. Because tobacco in one hogshead could be from various farms subjected to diverse insecticides, a sampling method was developed that would yield a small portion of tobacco containing residues representative of the entire hogshead of tobacco. A l-in.-by-48-in. core of tobacco was taken from each hogshead at a point 12 inches from the outer edge of the upright container. Analysis of a thoroughly mixed sample collected in this manner gave results comparable to those obtained by analyzing 100 10-g subsamples from a hogshead of tobacco which has been chopped and mixed by commercial means (5). Four different storage sites in Kentucky were selected for sampling, one each in areas II, III, IV, and V (Fig. 1). The specific warehouses were selected because they contained tobacco produced in that area, and be- cause of the large number of crop years for which tobacco was available. When possible, three different grades of tobacco from each crop year were collected from each sampling site. The grades preferred were B3F, C4F, and X3F because they contain leaves ap- proximating the top, middle, and bottom portions of the tobacco plant. When these grades were not available, similar grades were sampled; in some cases, similar grades were not available so no sample was taken. For crop years 1965 and 1967-70, 2 hogsheads of each grade were sampled from areas II-V, making a total of 8 hogsheads per grade per year. Grade B, 1963 tobacco was not available in areas III, IV, and V; nor were B and C grades of the 1964 crop in area III. Sampling of the 1966 crop was complete except that there was no grade B tobacco in area II. Two core samples were taken from each hogshead; the tobacco from each was cut into cigarette-size particles and thoroughly mixed. Two 10-g subsamples from each core were analyzed. Auction Warehouse Tobacco For sampling purposes, Kentucky was divided into six areas (Fig. 1 ) and tobacco was collected from as many counties and individual farms within the area as were available at the time of collection. Three hands of tobacco from each farm were collected: one hand each from the top, middle, and bottom leaves of the tobacco plant. A composite sample also was taken which con- sisted of equal quantities of the top, middle, and bottom leaves. The four samples were individually cut into cigarette-size particles, combined with like samples from the same area, and thoroughly mixed. Two 10-g sub- samples were removed for analysis. The numbers of counties and farms represented for each area and crop year are shown in Figure 1. Separate analyses were performed on the top, middle, bottom, and composite leaves from each area for the crop years 1968-72. ' IV \ ^ — W<.w ^— ~\ /-v^ y^ r«»jic,if r** "^*" .■■ \.^^— \^ V /f ) J, r V itM- K.JOl / y /L J ! IM»-UC,.II ~/ ^ r ....-„,,. T :"-'^- i Y c^ 3 IJJ;;!^!^ >*r)->K,lii "'-■. V ..■■■■' z^z y C WJO- 1, r — -i ill / VI /^ _J FIGURE 1. — Map of Kentucky showing areas from wliicli tobacco samples were taken, and number of counties (C), and farms (F) represented by auction warehouse samples for indicated crop years. All analyses were performed during 1972 and early 1973 using identical procedures for all samples. Tobacco from the Burley Tobacco Pool was stored in hogsheads, as stated earlier; tobacco samples collected annually from the auction markets were placed in plastic bags and held in the laboratory until analyzed. Extraction and Cleanup Tobacco samples were extracted overnight in a soxhlet apparatus with a 9:1 mixture of chloroform and methanol (6). Florisil column cleanup of the extracts 206 Pesticides Monitoring Journal for analysis of all chlorinated insecticides except en- dosulfan was identical to that described by Skrentny and Dorough (7). A deactivated florisil column, 2% water, was used for extracts being analyzed for en- dosulfan (4). Gas Chromatography Two Varian Aerograph Model 1700 instruments equipped with tritium electron capture detectors were used in these experiments. One chromatograph con- tained a 6 ft.-by-Vs-in. pyrex column packed with a 1:1 mixture of 4% SE30 and 6% QFl on 80/90-mesh Anakrom ABS. The temperatures of the injector, column, and detector were 215°C, 200°C, and 210°C. A column of the same size containing 5% OV-210 on 100/200-mesh Chromosorb W-HP was used with the other instrument. The injector temperature was 210°C, the column was 180°C, and the detector was 2I0°C. Nitrogen, 40 ml/min, served as the carrier gas for both instruments. Chromatograms of the various insecticide standards and tobacco extracts obtained with these gas chroma- tographic systems are illustrated in the paper by Dorough and Gibson (4). Minimum detectable levels of the insecticides in tobacco were 0.01 ppm for p,p'-DDT, o,p-DDT, p.p'-TDE, o.p-TDE, p.p'-DDE. dieldrin, en- drin, chlordane, endosulfan I and II; 0.05 for endosulfan sulfate; and 0.5 ppm for toxaphene. Average recoveries of the insecticides when added to control tobacco ex- ceeded 90% for all materials except endosulfan sulfate and toxaphene; recoveries of these insecticides averaged 88 and 80%, respectively. The extraction procedure reported here removed from 25 to 80% more chlori- nated insecticide residues from tobacco than did certain other extraction methods commonly employed (7). Data were not corrected for recovery. Mass spectrometry (Finnigan Model 1015C GC/MS System) was used to confirm the findings. Results and Discussion FREQUENCY OF OCCURRENCE DDT and/ or TDE residues were present at detectable levels in all tobacco samples analyzed in this study (Table 1). During the period from 1963 to 1969, all samples except some of the 1964 tobacco crop con- tained residues in excess of 5 ppm and many contained over 25 ppm of DDT-TDE. Over 80% of the tobacco produced in 1966-69 contained DDT-TDE residues in excess of 25 ppm, but in the 1971 crop the residues were less than 5 ppm in 50% of the samples. DDT-TDE residues on the 1972 crop were below 1 ppm. Dieldrin also was present on most of the tobacco sampled from the Burley Tobacco Pool and from the auction warehouses. Among samples from the 1964 and 1970 tobacco crops, 90% and 96% contained diel- drin. All other samples from the Burley Tobacco Pool were contaminated with this insecticide. All tobacco collected from the auction warehouses contained diel- drin up to the 1972 crop, in which 33% of the samples were free of detectable levels of residues. Endrin was the third most common chlorinated insecti- cide on tobacco: only the 1968 and 1969 auction market samples did not show endrin residues at some level. Unlike dieldrin, endrin was not detected in 100% of the samples for any crop produced between 1963 and 1972. Usually, less than half the samples analyzed for any given crop year contained this material. Also, the TABLE 1 . — Frequency of occurrence of chlorinated insecticide residues in Kentucky Burley tobacco. Percent of samples containing Toxaphene Endosulfan Dieldrin Endrin Total DDT-TDE Crop Year 0-1 PPM 1-5 PPM 5-25 PPM 25+ PPM BURLEY TOBACCO POOL SAMPLES 1963 17 0 too 72 0 0 100 0 1964 0 0 90 60 0 25 40 35 1965 4 0 100 29 0 0 71 29 1966 4 0 100 45 0 0 9 91 1967 0 0 100 21 0 0 17 83 1968 0 0 100 25 0 0 13 87 1969 8 96 100 30 0 0 4 96 1970 8 100 96 17 33 50 17 0 AUCTION WAREHOUSE SAMPLES 1968 0 35 100 0 0 0 0 100 1969 0 35 100 0 0 0 0 100 1970 17 100 100 17 0 60 33 7 19711 0 83 100 50 50 17 33 0 1972 0 100 67 33 100 0 0 0 ^ 83% of these samples also contained chlordane. Vol. 7, No. 3/4, March 1974 207 occurrence of endrin on tobacco was not evenly dis- tributed across the state as were DDT and dieldrin resi- dues. For example, of the 64 hogsheads containing en- drin-contaminated tobacco (a total of 180 were sampled for 1963-70), 39 were in area II; 13. in area III; 5, in area IV; and 7. in area V (Fig. 1). Areas I and VI were not included in the Burley Tobacco Pool experiments because of the relatively low quantities of tobacco pro- duced in these areas. Toxaphene was not a general contaminant of tobacco produced in Kentucky during 1963-72, but did occur sporadically and sometimes at very high levels. Residues of toxaphene were not detected on any samples of tobacco collected from areas IV, V, and VI. Low levels of chlordane were present on 83% of the auction ware- house samples collected in 1971 but none was detected in any other tobacco samples. Endosulfan residues appeared on about one third of the tobacco sampled from the auction markets in 1968 and 1969. In subsequent years endosulfan was a general contaminant, present in all 1970 and 1972 samples and in 83% of the 1971 auction warehouse tobacco. Its high rate of occurrence on Burley tobacco produced after 1968 was verified by analysis of the Burley Tobacco Pool samples. Table 1 shows some differences in the frequency with which insecticides occurred on the Burley Tobacco Pool compared to samples from the auction warehouses for the same crop year. These differences become even more apparent in later discussions which consider spe- cific levels. Generally, the Burley Tobacco Pool samples would more accurately represent average residue levels for a given area, or for the State as a whole. This is because a single hogshead of tobacco may contain tobacco produced by as many as 20 farmers at any location within any designated area. For most crop years from 1963 to 1970, 8 hogsheads were sampled from each area. This would represent tobacco from 100 to 200 producers from that area each year and the resulting data would be indicative of the residues for the area as a whole. On the other hand, samples from the auction markets were taken from three or four specific warehouses with- in an area, usually representing crops produced by only 10 to 20 farmers for each area and crop year. Moreover, areas I and VI (Fig. 1) were included in the auction warehouse studies and information from these areas are included in all data reflecting average residue levels on tobacco on a statewide basis (Tables 1, 3, 7, 9). Similar data from the Burley Tobacco Pool samples (Tables 1 , 2. 6. 8) would not include tobacco from areas I and VI. These factors could certainly be responsible, at least in part, for the differences observed in insecti- cide occurrence and levels on tobacco samples taken from the Burley Tobacco Pool and the auction ware- houses for the same crop years, although the differences were not dramatic. TOTAL CHLORINATED INSECTICIDE RESIDUES ON STATEWIDE BASIS The average levels of chlorinated insecticide residues on Burley tobacco produced in Kentucky during 1963- 72 were of three definite magnitudes. Tobacco crops produced in 1963-65 contained average residues of 20 ppm; tobacco produced in 1966-69, about 50 ppm; and that produced after 1969, less than 15 ppm (Tables 2, 3). Total chlorinated insecticide residues continued to TABLE 2. — Chlorinated insecticide residues, ppm. in tobacco .sampled from Kentucky Burley Tobacco PooF Total Total Crop Year DDT-TDEs Dieldrin Endrin Endosulfan Toxaphene Residues 1963 12.26 0.40 0.36 0 7.53 20.55 1964 20.06 0.32 0.30 0 0 20.68 1965 25.55 0.46 0.22 0 0.28 26.51 1966 52.99 0.84 0.25 0 0.67 54.75 1967 50.62 0.70 0.19 0 0 51.51 1968 50.96 0.84 0.14 0 0 51.95 1969 53.02 0.86 0.28 0.86 0.68 55.70 1970 3.54 0.26 0.06 2.68 1.92 8.46 1 Values are averages of analyses of all hogsheads sampled for indicated vear. Number of hogsheads sampled: 18 in 1963, 20 in 1964, 22 in 1966, and 24 in 1965 and 1967-70. TABLE 3. — Chlorinated insecticide residues, ppm, in Burley tobacco sampled from auction warehouses in Kentucky' Total Total Crop Year DDT-TDEs Chlordane Dieldrin Endrin Endosulfan Toxaphene Residues 1968 54.68 0 0.61 0 0.23 0 55.52 1969 53.24 0 0.94 0 0.30 1.62 56.10 1970 8.16 0 0.59 0.07 4.19 1.14 14.15 1971 3.18 0.27 0.12 0.12 4.60 0.46 8.75 1972 0.29 0 0.04 0.06 4.10 0 4.49 ^ Values are averages of all analysis of samples collected for indicated year. 208 Pesticides Monitoring Journal decline steadily after the very significant drop which oc- curred in the 1970 tobacco crop, averaging less than 5 ppm in 1972 (Table 3). DDT-TDE constituted over 90% of the total chlorinated insecticide residues on tobacco when residues were at their peak level during 1966-69. The decline in later years was brought about largely by a reduction in levels of these residues. The most significant point was the low level to which they declined: from 53 ppm in 1969, to 0.3 ppm in 1972. Dieldrin residues on Burley tobacco ranged from 0.26 to 0.94 ppm on a statewide basis in the 1963-70 tobacco crops (Tables 2, 3). The average level during this period for tobacco sampled from the Burley Tobacco Pool was 0.60 ppm (Table 2). Endrin levels on the 1963-65 to- bacco, 0.2-0.4 ppm, were approximately equal to those of dieldrin. However, endrin residues remained about the same through 1969. whereas levels of dieldrin in- creased during the late sixties. Analysis of the 1968 and 1969 auction market samples did not reveal any endrin residues, but low levels were present on the 1970-72 tobacco (Table 3). Like the DDT-TDE's, levels of dieldrin and endrin steadily de- cline on tobacco produced after 1969; the average level of dieldrin and endrin on the 1972 crop was 0.04 ppm and 0.06 ppm, respectively. As stated earlier, toxaphene was not present on a large number of samples. However, some individual samples contained more than 100 ppm of this insecticide, caus- ing its levels in tobacco, considered statewide, to appear significant in some cases (Table 2). The toxaphene resi- dues shown in Table 2 were in tobacco from only 9 of the 180 hogsheads sampled; 4 from area II, and 5 from area III. Therefore, toxaphene was not a general con- taminant of Kentucky Burley tobacco, nor of tobacco in areas II and III. No toxaphene was detected in 79 of the 88 hogsheads from these areas. Endosulfan first appeared on the 1968 tobacco crop, but on a statewide basis averaged only 0.23 ppm (Table 3). In 1969, the levels remained fairly low, less than 1 ppm (Tables 2. 3), but increased markedly to over 4 ppm in the 1970-72 Burley tobacco (Table 3). Its TABLE 4. — Chlorinated insecticide residues, ppm, in tobacco sampled from Kentucky Burley Tobacco Pool according to area of production and crop year Area, P,P'- o.p- P.P'- o.p- P,P'- Total Endo- Toxa- Total Year DDT DDT TDE TDE DDE DDT-TDE sulfan Dieldrin Endrin phene Residues Area II 1963 3.16 0.93 6.17 1.45 0.40 12.11 0 0,68 0,83 29.32 42.93 1964 5.57 0.71 15.78 4.13 0.66 26.85 0 0,55 0,96 0 28.36 1965 9.94 1.14 28.96 8.71 0.80 49,54 0 1.03 0.84 0 51.42 1966 27.55 2.72 34.60 10.13 1.63 76.64 0 1.26 0.96 0 78.86 1967 32.11 3.15 39.29 7.31 2.15 84.02 0 1.39 0.75 0 86.16 1968 19.22 1.91 41.14 7.02 1.70 70.99 0 1.47 0.50 0 72.96 1969 24.06 2.28 45.84 8.93 1.60 80.71 0,94 1.22 1.05 0 83.92 1970 1.48 0.18 3.12 1.81 0.14 6.74 3,40 0.31 0.25 7.68 18,37 Area III 1963 1.39 0.19 9.15 1.74 0.14 12.61 0 0,22 0.61 0.81 14.24 1964 5.62 0.90 13.44 2.90 0.64 23.51 0 0,36 0.20 0 24,07 1965 5.45 0.77 12.21 2.61 0.54 21.58 0 0,34 0.02 1.10 23,05 1966 31.68 2.78 24.16 4.34 1.98 64.94 0 0,68 0.02 2.68 68.32 1967 15.36 1.68 26.04 6.01 1.33 50.42 0 0,62 0 0 51,04 1968 16.97 1.64 22.07 4.21 0.88 45.77 0 0,65 0.10 0 46,52 1969 17.64 2.04 32.47 8.50 1.34 62.00 0,88 1.09 0.05 2.70 66,71 1970 1.68 0.22 1.41 0.35 0.07 3.74 3.04 0.26 0,01 0 7.04 Area IV 1963 0.93 0.09 7.83 2.00 0.13 10.97 0 0.31 0.01 0 11.28 1964 7.08 0.79 5.48 1.06 0.78 15.16 0 0.10 0 0 15.26 1965 6.02 0.72 4.79 1.23 0.74 13.50 0 0.19 0 0 13.68 1966 16.67 1.64 16.95 3.90 1.57 40.72 0 0.44 0.01 0 41.17 1967 12.53 1.08 14.68 2.31 1.04 31.64 0 0.21 0 0 31.85 1968 14.15 1.38 12.97 2.72 1.29 32.50 0 0.47 0 0 32.98 1969 14.16 1.45 12.78 2.37 0.99 31.74 0,88 0.52 0 0 33.14 1970 0.17 0.02 1.36 0.34 0.01 1.90 1,40 0.27 0 0 3.56 Area V 1963 3.16 0.53 7.14 2.11 0.40 13.33 0 0.39 0.02 0 13.74 1964 3.62 0.42 8.13 2.09 0.45 14.72 0 0,27 0.04 0 15,03 1965 3.77 0.47 10.24 2.67 0.44 17,58 0 0,30 0.01 0 17.90 1966 12.28 1.42 12.18 2.93 0.86 29,66 0 1,00 0 0 30.66 1967 9.40 1.11 20.15 4.65 i.n 36,41 0 0,57 0 0 36.98 1968 23.26 2.07 24.56 3.60 1.06 54.56 0 0,78 0 0 55.34 1969 14.38 1.28 18.11 3.16 0.69 37.61 0,76 0,60 0 0 38.98 1970 0.54 0.09 0.77 0.34 0,05 1.80 2,86 0,21 0 0 4.86 Vol. 7, No. 3/4, March 1974 209 ubiquitous nature and the fact that many samples con- tained 10 to 20 ppm endosulfan is not unlike the situa- tion in the early 1960's regarding DDT-TDE residues on tobacco. RESIDUES IN RELATION TO AREA OF PRODUCTION AND CROP YEAR Of the four areas in Kentucky from which Burley Tobacco Pool samples were collected (Fig. 1), the highest levels of total chlorinated insecticide residues were always found in tobacco from area II (Table 4). The average level for the 8-year period was 58 ppm. During 6 of the 8 years, tobacco from area IV contained the lowest quantity of insecticide residues: area V tobacco was lowest the other 2 years. Eight-year averages for areas IV and V were 23 ppm and 27 ppm, respectively. Tobacco from area III always contained residues higher than those from area IV and, except for the 1968 crop, lower than area V. Total chlorinated insecticide residues on area III tobacco averaged 38 ppm for the crop years 1963-70. Analysis of the auction warehouse tobacco samples showed that area I tobacco was similar in insecticide content to that from area II (Table 5). Area VI tobacco proved to be lower in chlorinated insecticide content than tobacco from any of the areas in which samples were collected in 1970-72. Average total residues were TABLE 5. -Chloriiialeil inxecticicic residues, ppm, in Burley tobacco sampled from aiiclioii wurelwuses in Kcniiicky accordiiif; lo area of production and crop year Area, P,P'- o.p- P.P'- o.p- P.P'- Total Chlor- Endo- DlEL- En- TOXA- Total Year DDT DDT TDE TDE DDE DDT-TDE DANE sulfan DRIN DRIN PHENE Residues Area I 1970 4.29 0.48 8.30 1.54 0.21 14.82 0.00 14.63 2.22 0.00 6.62 38.29 1971 2.73 0.79 5.21 1.21 0.21 10.15 0.15 13.78 0,15 0.55 0 24.78 1972 0.29 0.11 0.10 0 0.03 0.53 0 7.45 0,08 0.07 0 8.13 Area II 1970 5.12 0.38 23.49 5.37 0.20 34.56 0 3.21 0,71 0.63 0 39.11 1971 1.52 0.40 5.79 1,23 0.09 9.03 0.08 10.85 0.14 0,62 0 20.72 1972 0.20 0.07 0.09 0 0.02 0.38 0 5.46 0.02 0.43 0 6.29 Area III 1968 1.17 0.56 24.93 4.63 0.07 3 1 ,76 0 0 0.73 0 0 32.49 1969 16.14 2.06 39.02 9.97 0.88 68.07 0 0 1.23 0 4.07 73.37 1970 0.24 0.16 1.70 0.39 0 2.49 0 2.28 0.10 0 0 4.87 1971 0.12 0.11 1.27 0.28 0 1.78 0,06 2.81 0.19 0.25 0 5.09 1972 0.19 0.07 0.06 0 0.02 0.34 0 3.65 0 0 0 3.99 Area IV 1968 35.23 5.32 12.15 0.92 0.71 54.33 0,00 0.00 0.27 0.00 0.00 54.60 1969 14.41 2.16 19.33 4.77 0.97 41.64 0 0 0.99 0 0 42.63 1970 0.22 0.11 0.80 0.29 0 1.42 0 2.93 0.64 0 0 4.99 1971 0.11 0.09 0.13 0.03 0.01 0.37 0,04 0.89 0.07 0 0 1.37 1972 0.08 0.03 0.04 0.01 0.01 0.16 0 2.59 0.07 0 0 2.85 Area V 1968 16.69 2.89 20.57 3.87 0.95 47.94 0 0.90 0.90 0 0 49.74 1969 19.83 2.19 17.29 2.76 0.83 42.90 0 1.06 0.86 0 0 44.82 1970 2.95 0.69 8.86 1.63 0.09 14.22 0 3.26 0.47 0 0 17.95 1971 0.07 0.05 0.11 0.03 0.01 0.27 0 1.39 0.08 0 0 1.78 1972 0,09 0 0.04 0 0 0.13 0 1,91 0.04 0 0 2.08 Area VI 1970 0.74 0.17 1,27 0.36 0 2.54 0 0,55 0.05 0 0 3.14 1971 0.05 0.09 0.05 0.01 0 0.16 0.05 0 0.02 0 0 0.25 1972 0.06 0 0.04 0 0 0.10 0 0,12 0 0 0 0.22 I TABLE 6. — Endosulfan components in tobacco sampled from Kentucky Burley Tobacco Pool PPM AND percentage OF TOTAL ON TOBACCO FOR CROP YEARS ' 1969 1970 Endosulfan Endosulfan Grade I II Sulfate Total I II Sulfate Total B3F 0.10 0.35 0.19 0.64 0.22 1.17 1.12 2.51 C4F 0.08 0.31 0.44 0.83 0.23 1.13 1.30 2.66 X3F 0.14 0.34 0.65 1.13 0.24 1.17 1.32 2.73 Average 0.11 (12.6) 0.33 (37.9) 0.43 (49.5) 0.87 0.23 (8.8) 1.16 (44.1) 1.25 (47.1) 2.63 Values represent average of analysis of tobacco froin 8 hogsheads: 2 of each grade each year from each area, II-V, described in Fig. 1. 210 Pesticides Monitoring Journal TABLE 7. — Endosulfan components on Burley tobacco samp led from auction markets in Kentucky Crop year PPM AND PERCENTAGE OF TOTAL ON LEAVES FROM DIFFERENT PORTIONS OF PLANT ' INSECTICnXE Top Middle BOTTOM Average Composite - 1970 Endosulfan I 0.65 0.80 0.86 0.77 (18.9) 0.78 (17.4) Endosulfan II 1.13 1.15 1.22 1.17 (28.5) 1.38 (30.8) E. Sulfate 1.86 2.33 2.30 2.16 (52.6) 2.32 (51.8) Total 3.64 4.28 4,38 4.10 4.48 1971 Endosulfan I 0.51 0.88 0.90 0.76 (18.5) 0.80 (16.1) Endosulfan II 2.51 1.03 1.56 1.70 (41.4) 2.27 (45.8) E. Sulfate 1.40 1.41 2.15 1.65 (40.1) 1.89 (38.1) Total 4.42 3.32 4.61 4.11 4.96 1972 Endosulfan I 0.29 0.31 0.66 0.42 (8.3) 0.25 (7.1) Endosulfan II 0.79 1.13 2.64 1.52 (16.1) 0.81 (23.0) E, Sulfate 2.60 3.57 3.12 3.10 (75.6) 2.47 (69.9) Total 3.68 5.01 6.42 5.04 3.53 ^ Average of all samples analyzed for indicated year. - Sample consisting of equal quantities of top, middle, and bottom leaves. TABLE 8. — Clilorinated insecticide residues, ppm, in differ- ent grades of tobacco sampled from Kentucky Burley Tobacco PooP TABLE 9. — Chlorinated insecticide residues, ppm, in to- bacco sampled from auction markets in Kentucky according to position of leaves on planf Crop Grade Year B C X Average 1963 14.82 37.45 9.38 20.55 1964 29.78 17.83 14.43 20.68 1965 24.88 24.41 30.25 26.51 1966 51.25 59.80 53.20 54.75 1967 55.37 43.66 55.50 51.51 1968 56.34 50.09 49.42 51.95 1969 47.53 48.87 70.70 55.70 1970 8.95 9.59 6.84 8.46 Average 36.12 36.46 36.21 36.26 Years high, % 25 38 38 — Years medium, 9o 50 38 12 — Years low, % 25 25 50 — 1 Values are averages of analysis of all hogsheads sampled for indicated year; 8 hogsheads/grade/year in 1965 and 1967-70; 8 hogsheads each for grades X and C, 2 for grade B in 1963; 8 hogsheads for grade X and 6 each for grades B and C in 1964; 8 hogsheads each for grades X and C and 6 for grade B in 1966. only 3.14 ppm in 1970 aniJ below 0.3 ppm in 1971 and 1972. Residues on the 1972 crop from other areas aLso were much lower than in 1970, especially in areas I and II where total residues averaged over 20 ppm in 1971 but were 8 ppm and 6 ppm, respectively, in 1972. It was particularly noteworthy that total DDT-TDE residues were so low in all 1972 tobacco (Table 5). These findings eliminated the possibility that the previ- ous use of DDT and/ or TDE for many years, and at high rates, would result in significant contamination of subsequent tobacco crops even after these insecticides were discontinued. Tables 4 and 5 show numerous instances in which DDT-TDE residues dropped to 1 ppm or less in tobacco produced in an area where, just the year before, the crop had contained over 20 ppm. This proved to be the case even in area II where the Position on plant ppm on Com- posite Crop Year Top Middle Bottom Average Sample - 1968 61.08 58.35 57.07 58.83 45.61 1969 48.61 63.10 59.09 56.93 53.61 1970 UA2 17.04 10.46 13.97 18.06 1971 9.92 6.68 9.21 8.66 9.00 1972 4.01 5.32 4.74 4.69 3.92 Average 22.61 30.10 28.11 28.60 26.04 Years high. % 40 60 0 — — Years medium, % 20 20 60 _ — Years low, % 40 20 40 — — * Values are averages of analysis of all samples analzed for indicated year. - Sample consisting of equal portions of top, middle, and bottom leaves. residues were highest each of the past 10 years. In fact, the most dramatic reduction in any single year occurred in area II where total DDT-TDE residues were 80.7 ppm in 1969 and only 6.7 ppm in 1970. Determining relative concentrations of the individual components comprising the total DDT-TDE residues showed that the ratios of the compounds varied con- siderably from sample to sample (Tables 4, 5). By averaging the results of all tobacco samples analyzed in this study, it was found that total DDT-TDE residues consisted of 50% p,p'-TDE, 30% p.p'-DDT, 12% 0./7-TDE. 6% o,p-DDT, and 2% p,p'-DDE. Only after total residues on tobacco had declined to the point that minor components could no longer be detected, could a consistent variation from these average values be ob- tained. This had little meaning, however, since all five components were usually present in samples containing 0..5 ppm, and sometimes less, of either p.p'-DDT or p.p'-JDE. Vol. 7, No. 3/4, March 1974 211 Concomitant with the decline of DDT-TDE residues was the increased levels of endosulfan in tobacco. Maximum levels, up to 14 ppm, occurred in tobacco from areas I and II, but generally declined as the area of crop production moved eastward across the State. Area VI tobacco contained 0.55 ppm endosulfan in 1970, none in 1971, and only 0.12 ppm in 1972. Except for areas 1 and II, higher endosulfan residues were found in the 1972 tobacco than in the 1971 material. Generally, the levels of dieldrin and endrin varied according to area of production and crop year in much the same manner as the DDT-TDE residues. By 1972, the levels had declined to a point where the highest level of dieldrin in any ;u-ea was only 0.08 ppm (Table 5) and this occurred in area I. None of the 1972 samples from area III or VI contained dieldrin. Endrin residues of relatively high quantities, 0.43 ppm, were in the 1972 tobacco from area II, but were only 0.07 ppm in area I. All other samples were free of endrin residues in 1972. Of all samples collected from the auction warehouses, toxaphene was detected only in the 1969 area III and the 1970 area I tobacco. ENDOSULFAN It was evident from analyses of both the Burley Tobacco Pool and auction warehouse samples that many tobacco producers were using endosulfan as a replacement for DDT and TDE. Residues of endosulfan rose sharply in crops produced after 1969, the last year DDT and TDE were approved for control of tobacco insect pests. Be- cause endosulfan is still approved for use on tobacco and was the predominant chlorinated insecticide residue on the 1971 and 1972 Burley tobacco crops, a more critical evaluation of its residual nature in tobacco is presented in Tables 6 and 7. Total endosulfan residues consisted of the two isomers of the compound, endosulfan I and II, and endosulfan sulfate. Analysis of the three endosulfans on tobacco leaves from the top (B3F), middle (C4F), and bottom (X3F) of the plant showed that the bottom leaves con- tained the highest concentrations of total endosulfan residues. Generally, endosulfan residues were somewhat higher in the middle leaves than in the top ones. Al- though the differences were consistent, the magnitude was usually less than 1 ppm between the top and bottom leaves. Actually, it might be expected that the top leaves would contain the higher level of residues since endo- sulfan is applied as foliar spray to tobacco. It may be that residues on the lower portion of the plant are pro- tected from weathering by the upper foliage, thus slow- ing dissipation rates. Another contributing factor could be dilution by growth of the upper leaves when younger plants are sprayed. In most of the tobacco analyzed, endosulfan sulfate ac- counted for 40 to 50% of the total endosulfan residues. Endosulfan II constituted 30 to 40% and the remaining 10 to 20% was endosulfan I. The 1972 tobacco crop, however, showed a different pattern (Table 7). Endosul- fan sulfate was approximately 70% of the total residues; endosulfan II, about 20%; and endosulfan I, only 8%. Whether this is typical of newly harvested tobacco was not ascertained. However, it is unlikely that these data mean that significant changes in composition of en- dosulfan residues took place during storage of the 1969-70 tobacco samples. If this were the case, en- dosulfan sulfate residues should be less in newly harvested samples; they are formed from endosulfan I and II, and this conversion would have more time to occur in the stored tobacco. The fact that the relative concentrations of the endosulfan components were fairly similar on all tobacco suggests that little dissipation and/ or conversion of endosulfan residues to other products occurred during storage. RES1DUE.S IN RELATION TO GRADE OF TOBACCO Tobacco stored in hogsheads by the Burley Tobacco Pool is graded before being placed in storage and this information is recorded on each container. Grades B3F, C4F, and X3F were sampled for residue analysis whenever possible because these grades generally repre- sent the top, middle, and bottom leaves of the tobacco plant, respectively. Samples from the auction warehouses were taken before being graded but the samples were taken based on the position of the leaves on the intact plant. Therefore, it was possible to correlate levels of residues with grades of tobacco in samples taken from the Burley Tobacco Pool and the auction markets. The 8-year average chlorinated insecticide residue levels on the Burley Tobacco Pool samples were almost identical for all three grades of tobacco (Table 8). Dur- ing this period, however, grades B and C contained the lowest level of residues only 25% of the time; grade X tobacco was lowest of the three grades 50% of the time. Residues on grades C and X were higher than grade B material 38% of the time. Grade B material was highest 25% of the time. During the years when residues were in the low and/ or medium range, grade B tobacco was highest 75% of the time. These data do suggest a trend in regard to residue levels and grades of tobacco, but the differences are so small and incon- sistent that it is impossible to consider them of any practical importance. A similar conclusion may be drawn from data in Table 9 which show residue levels on the top, middle, and bottom leaves of tobacco sampled from auction ware- houses. Average residue levels of chlorinated insecticides for crop years 1968 through 1972 were 23 ppm for the top leaves, 30 ppm for the middle leaves, and 28 ppm for the bottom leaves. As expected, these values were 212 Pesticides Monitoring Journal less than the 8-year averages, 36 ppm, for tobacco stored in the Burley Tobacco Pool (Table 8). Calculating the frequency with which residue levels were either high, medium, or low on leaves from different positions of the tobacco plant failed to demonstrate a definite pattern of residue distribution (Table 9). The fact that these data on the auction market samples were diflferent from but as variable as those for the Burley Tobacco Pool samples supports the conclusion that residue levels were in- dependent of grade of tobacco. Data in Tables 7 and 9 suggest that, for monitoring purposes, a composite sample consisting of equal quanti- ties of top, middle, and bottom leaves would be a valid sample for analysis of the chlorinated insecticides. Actu- ally, a sample taken from any one portion of the plant might serve the same function. However, if the apparent trend toward lower residues on top leaves is real as indicated by the data on endosulfan (Table 7), a com- posite sample would be of greater value in determining the level of residues on an entire tobacco crop. It is significant that the findings of this study are limited to the chlorinated insecticides and that the distribution of other pesticides on tobacco could differ significantly. Soil-applied systemic pesticides, in particular, might be different from the chlorinated insecticides investigated in this study. With few exceptions, these latter materials are applied as sprays directly on the plant and con- tamination is dependent largely on mechanical factors and ambient conditions. Contamination of tobacco by systemic insecticides would normally involve complex interactions of the chemical with various biochemical and physiological processes of the tobacco plant. LITERATURE CITED (/) Anonymous. 1966. Bundesgesetzblatt 655, Tail 1, 21997- A, Ausgegeben Zun Bonn am. 10 Dezember 196fi, Nr. 53. Amended Jan. 18, 1972. (2) Gtirhrie, F. E. The nature and significance of pesticide residues on tobacco and in tobacco smoke. Beitr. To- bokforsch. 4: 229-246. (3) Sheet.';. T. J., J. W . Smith, anil M. D. Jackson. 1968. Pesticide residues in cigarettes. Tob. Sci. 12:66-69. (4) Doioiigh. H. W. and J. R. Gibson. 1972. Chlorinated insecticide residues in cigarettes purchased 1970-72. En- vir. Entomol. 1: 739-743. (5) Gibson. ]. R.. H. W. Borough. G. A. Jones, and H. E. McKean. 1973. A sampling method for estimating the mean insecticide content of tobacco stored as hands in hogsheads. Tob. Sci. 17: 65-67. (6) Bowman. M. C. M. Beroza. and C. R. Gentry. 1969. GLC determination of residues of disulfoton, oxyde- metonmethyl and their metabolites in tobacco plants. J. Assoc. Anal. Chem. 52: 157-162. (7) Skrentny, R. F. and H. W. Borough. 1971. Efficiencies of several extraction procedures in removing organo- chlorine insecticides from tobacco. Tob. Sci. 15: 111-1 13. Vol. 7, No. 3/4, March 1974 213 BRIEF Mercury Levels in Soils of the Eastern United States G. B. Wiersma' and H. Tai' ABSTRACT Cropland and noncrophind soils were sampled to determine levels of elemental mercury present in the upper three inches of soil. Results showed no difference in mercury levels be- tween cropland and noncropland soils. Levels detected com- pared closely to levels found in similar studies. Actual mean levels of mercury residues in soils of the eastern United States ranged from 0.05 to 0.10 ppm. Introduction This study is an effort to determine baseline levels of elemental mercury in cropland and noncropland soils in the eastern United States. These baselines, in turn, will be used for comparison with results from continu- ing soil monitoring efforts for pesticides containing mercury. Several estimates have been made of baseline levels of mercury in soils, both in the United States and abroad. Warren and Delavault (/) reported very high concentra- tions of mercury in certain British soils ranging as high as 15 ppm. They estimated, however, that the levels of mercury in most British agricultural soils would prob- ably range between 0.01 and 0.06 ppm. Anderson (2) analyzed soils in Sweden and found that ranges for mercury in these soils varied from 0.02 to 0.92 ppm with an average of 0.07 ppm. Sand et al, (i) reported mercury residues in wheat-growing areas of the north- central United States. Pierce et al., (4) reported mercury concentrations in soil from four areas in the western United States. The 50 ' Ecolopic-il Monitoring Branch, Technical Services Division. Office of Pesticides Programs. U.S. Environmental Protection Agency. Wasli- ington, D C. - Ecological Monitoring Branch, Technical Services Division, Office of Pesticides Programs, U.S. Environmental Protection Agency, Mis- sissippi Test Facility, Bay St. Louis. Mississippi. 214 percentile points for these four sets of data ranged from 0.071 ppm to 0.200 ppm. Shacklette et al. (5) collected 912 soil samples along widely scattered road systems in the continental United States. Sample sites were ap- proximately 50 miles apart. Sampling was conducted to the depth of 8 inches. The geometric means for mercury concentration in these soil samples for the entire United States was 0.071 ppm. The arthmetic mean was 0.112 ppm. The geometric mean for the western United States, 492 samples from west of the 97th meridian, was 0.055 ppm; the arith- metic mean was 0.083 ppm. The eastern United States, 420 samples, had a geometric mean of 0.096 ppm and an arithmetic mean of 0.147 ppm. Material and Methods Samples were collected as a subset of the National Soils Monitoring Program as described by Wiersma et al. (6). Sites were allocated according to the relative amounts of cropland and noncropland acreages in each State. Sites were chosen at random within the two categories. States sampled and the number of sites in each state are listed in Table 1. At each sampling point a 10-acre site was sampled. Fifty soil cores, 2 inches in diameter by 3 inches deep, were collected and composited with the use of a 5-by-lO grid. A 2-quart subsample was then taken and sent to the laboratory for analysis. The cropland samples were collected in the fall of 1968, along with noncropland samples from Georgia, Maine, Maryland, Virginia, and West Virginia. All other noncropland samples were collected in the spring of 1971. Pesticides Monitoring Journal TABLE 1. — Soil samples collected to determine mercury residues in surface cropland and noncropland areas of eastern United States Number of samples collected State Cropland Noncropland Alabama 6 6 Arkansas 13 5 Connecticut 1 1 Delaware 1 No samples tested Florida 5 7 Georgia 8 8 Illinois 41 3 Indiana 22 1 Kentcuky 8 4 Louisiana 8 5 Maine 2 2 Maryland 3 1 Massachusetts 1 1 Michigan 16 * Mississippi 9 5 Missouri 23 7 New Hampshire 1 1 New Jersey • I New York 11 5 North Carolina 8 6 Ohio 18 3 Oklahoma 19 7 Pennsylvania 11 5 South Carolina 5 3 Tennessee 8 5 Vermont 1 1 Virginia 7 4 West Virginia 3 2 Wisconsin 16 5 TOTAL 275 104 A Perkin-Elmer Model 303 Atomic Absorption Spectro- photometer with Automatic Null Recorder Readout was used for the measurements. The essential instrument conditions were: • No analyses available A nalytical Procedures The analyses were done by a commercial laboratory in West Chester, Pennsylvania, under contract with the U.S. Environmental Protection Agency. The flameless atomic absorption spectrophotometry was applied for the determination of mercury. Each soil sample, weighed exactly to 1.000 g, was dispersed in nitric acid solution (5 ml coned HNO.., in 100 ml water). Digestion at 90°C, for approximately 2 hours, took place in the presence of excess potssium permanganate (portions of 1 ml 5% KMn04 solution were added until purple color persisted) and 2 ml of 5% potassium persulfate solution. After digestion, the mixture was cooled to room temperature and filtered. The filtrate v/as mat; *o a volume of 100 ml, and 2 ml of sodium chloride-hydroxylamine reagent (12 q each in 100 ml water) was added to reduce the excess permanganate. Stannous sulfate solution (25 g in 250 ml of 0.5N H^,S04), 5 ml, was added to reduce mercury ions to elemental mercury, which was swept by an air stream through the absorption cell of the atomic ab- sorption spectrophotometer. The absorptions were meas- ured by peak height, and compared with a calibration curve. Vol. 7, No. 3/4, March 1974 Lamp: Lamp current: Wave length: Slit setting: Scale : Noise suppression: Mercury Hollow Cathode Lamp (Westinghouse WL-22847) 10 mA 253.7 nm 3 ■: 1 2 Precision study, using samples not reported in this paper, indicated a standard deviation of ± 0.16 at a level of 0.35 jjLg/WteT. with recovery average of 87%. The pre- sent procedure gave a detection limit of 0.05 fxg mercury (or 0.05 ppm per 1-g sample). Results and Discussion After testing the distribution form of our data, we found that the data for mercury levels were not nor- mally distributed with both positive skewness and signifi- cant kurtosis present. We found, however, that a loga- rithmic transformation helped the data to approach the normal distribution and to have a symmetric distribu- tion. Shacklette et al. used logarithms to transform their data. They felt that the geometric mean was the best estimate of the central tendency of the data. We have found in our work similar results; therefore, we present both the arithmetic and geometric means. Table 2 shows the geometric means, 95% confidence levels, arithmetic means, the percent of samples that had de- tectable residues, and the detection range of mercury levels in both cropland and noncropland soils. TABLE 2. — Summary of mercury residues detected in sur- face cropland and noncropland soils of the eastern United States Arith- Geometric Percent of metic Mean and Samples with Mean, 957c Confidence Range, Detectable ppm Interval, ppm PPM Residues Cropland 0.08 0.063 (0.069-0.058) <0.05 to 1.06 100.0 Noncropland 0.07 0.054 (0.064-0.046) <0.05 to 0.40 100.0 Mercury was present in all the samples collected at either a trace level or above. The difference between cropland and noncropland soils were not significant. This was determined from the overlapping confidence intervals. Although these samples were collected at different times, one would not expect mercury levels to change signifi- cantly from year to year. Shacklette et al. have stated (5), "Surficial materials an- alyzed in this study are ordinarily sampled at a depth of 8 inches. We believe that soils and other regoliths from this depth commonly show little or no effects of sur- ficial contamination that may have occurred." The sam- ples in this study were collected to include possible 215 contamination of surface soil by pesticides and other pollutants containing mercury. If there had been a significant amount of mercury contamination from manmade sources that had reached soils through air- borne or other routes, one would expect our samples to have considerably higher residues than those collected specifically to avoid surface contamination. However, the mercury levels reported in this study are actually lower than those reported by Shacklette et al. To summarize: in mercury levels of the eastern United States there is no statistical difference between cropland and noncropland soils. The levels detected in this study agree closely with levels detected in similar studies. Actual mean levels of mercury residues in the soils of the eastern United States ranged from 0.05 to 0.10 ppm. LITERATURE CITED (/) Warren, H. V. and R. E. DelavauU. 1969. Mercury con- tent of some British soils. Oikos 20: 537-539. (2) Anderson, A. 1967. Mercury in Swedish soils. Oikos (Supplement 9): pp. 13-15. (i) Sand, P. F., G. B. Wiersma. H. Tai and L. J. Stevens. 1971. Preliminary study of mercury residues in soils where mercury seed treatments have been used. Pestic. Monit. J. 5(1): 32-33. (4) Pierce, A. P., J. M. Botbol, and R. E. Learned. 1970. Mercury in the environment. Geological Survey Profes- sional Paper 713. U.S. Department of the Interior, pp. 14-16. (5) Shacklette, H. T.. J. G. Boemgen and R. L. Turner. 1971. Mercury in the environment — surficial materials of the conterminous United States. Geological Survey Circular 644. U.S. Department of the Interior. 5 pp. (6) Wiersma, G. B., P. F. Sand, and E. L. Cox. 1971. A sampling design to determine pesticide residue levels in soils of the conterminous United States. Pestic. Monit. J. 5(1): 63-66, 216 Pesticides Monitoring Journal APPENDIX Chemical Names of Compounds Discussed in This Issue BHC 2,4-D DDE DDT (including its isomers and dehydrochlorination products) DIELDRIN ENDOSULFAN (THIODAN®) ENDRIN HEPTACHLOR HEPTACHLOR EPOXIDE MERCURY MIREX POLYCHLORINATED BIPHENYLS (PCB's) TOE (DDD) (including isomers and dehydrochlorination products) TOXAPHENE 1,2,3,4,5,6-hexachlorocycIohexane, mixed isomers 2,4-dichlorophenoxyacetic acid l.l-dichloro-2,2-bis(p-chIorophenyI) ethylene l,l,I-trichloro-2,2-bis(p-chlorophenyl)ethane; technical DDT consists of a mixture of the p,p'-isomer and the o,p'-isomer (in ratio of about 3 or 4 to 1 ) Not less than 85% of l,2.3.4,10,10-hexachloro-6,7-epoxy-I,4.4a,5,6,7,8a-octahydro-l,4-^Hrfo-exo-5,8-dimethano= naphthalene 6,7,8,9,10,10-hexachloro-l,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin 3-oxide l,2,3,4,I0,I0-hexachloro-6,7-epoxy-l,4,4a,5,6,7,8,8a-octahydro-l,4-e»(/o-e/ido-5,8-dimethanonaphthalene l,4,5,6,7,8,8-heptachloro-3a,4,7,7a-tetrahydro-4,7-methanoindene I,4,5,6,7,8,8-heptachloro-2,3-epoxy-3a,4,7,7a-tetrahydro-4-7-methanoindan Hg dodecachlorooctahydro-I,3,4-metheno-l//-cyclobuta(crf) pentalene Mixtures of chlorinated biphenyl compounds having various percentages of chlorination l,l-dichloro-2,2-bis(p-chlorophenyl)ethane; technical TDE contains some o,p'-isomer also chlorinated camphene containing 67-68% chlorine Vol. 7, No. 3/4, March 1974 217 A cknowledgment The Editorial Advisory Board wishes to acknowledge with sincere appreciation the efforts of the following persons who assisted in reviewing papers submitted for publication in Volume 7, No. 1-4, of the Pesticides Monitoring Journal: U.S. DEPARTMENT OF AGRICULTURE Robert Williamson U.S. ENVIRONMENTAL PROTECTION AGENCY G. Bruce Wiersma FISH AND WILDLIFE SERVICE Thair G. Lamont FOOD AND DRUG ADMINISTRATION Helen Barry, Jerry Burke, P. E. Corneliussen, Patricia Cruz-LaGrange, Jean Gaul, Bernadette McMahon, Sidney Williams, George Yip 218 Pesticides Monitoring Journal SUBJECT AND AUTHOR INDEXES Volume 7, June 1973-IVIarch 1974 Preface Primary headings in the subject index consist of pesti- cide compounds, the media in which residues are moni- tored, and several concept headings, as follows: Pesticide Compounds (listed alphabetically by common name or trade name where there is no common name) Media and Concept Headings Degradation Experimental Design Factors Influencing Residues Food and Feed Humans Plants (other than those used for food and feed) Sediment Soil Water Wildlife Compound headings are also used as secondary headings under the primary media and concept headings and vice versa. When a particular paper discusses five or more organochlorines or three or more organophosphates or herbicides, the compounds are grouped by class under the media or concept headings; in the primary headings, however, all compounds are listed individually. The specific compounds or elements which have been grouped in various combinations by class for certain papers are as follows: Organoch lorines aldrin BHC/ lindane chlordane DCBP DDE DDT dieldrin endosulfan endrin heptachlor/heptachlor epoxide mirex TDE toxaphene Organophosphates diazinon malathion methyl parathion parathion Herbicides 2,4-D silvex 2,4,5-T In the author index, the names of both senior and junior authors appear alphabetically. Full citation is given, however, only under the senior author, with a reference to the senior author appearing under junior authors. Vol. 7, No. 3/4, March 1974 219 SUBJECT INDEX Aldrin Water 7(l):73-84 Arsenic WUdlife 7(I):67-72 B BHC/Lindane Factors Influencing Residues 7(l):27-36 7(3/4) :I22-126 Humans 7(l):I-5 7(3/4) :122-126 Water 7(l):73-84 Wildlife 7(l):27-36 7(2):97-99 Cadmium Wildlife 7(l):67-72 Chlordane Water 7(l):73-84 D 2,4-D Degradation 7(3/4): 146-152 Sediment 7(3/4) :I46-152 Water 7(l):73-84 7(3/4) :146-152 Wildlife 7(3/4); 146-152 DDD, see TDE DDE, see aUo DDT Factors Influencing Residues 7(l):27-36 7(3/4): 122-126 7(3/4): 153-164 7(3/4): 165-180 7(3/4) :181-194 Humans 7(l):l-5 7(3/4): 122-126 Sediment 7(3/4): 165-180 7(3/4) :20O-204 Soil 7(3/4): 200-204 Water 7(l):73-84 7(3/4) :165-180 7(3/4) :200-204 Wildlife 7(l):27-36 7(l):37-52 7(I):53-61 7(l):62-66 7(2) :97-99 7(2): 100-103 7(3/4) :153-164 7(3/4): 165-180 7(3/4) :181-194 7(3/4): 195-199 7(3/4): 200-204 220 DDT, see also DDE, TDE Degradation 7(3/4):165-180 Factors Influencing Residues 7(l):27-36 7(3/4) :122-126 7(3/4) :165-180 7(3/4) :181-194 Food and Feed 7(2):87-94 Humans 7(l):l-5 7(3/4) :122-126 Plants (other than those used for food and feed) 7(3/4) :205-213 Water 7(l):73-84 7(3/4) :165-180 Wildlife 7(I):l-5 7(l):37-52 7(1):53-61 7(l):62-66 7(2):97-99 7(2):100-103 7(3/4): 139-143 7(3/4) :153-164 7(3/4): 165-180 7(3/4) :181-194 7(3/4) :195-199 7(3/4): 200-204 Degradation Water 2,4-D 7(3/4): 146-152 DDT 7(3/41:165-180 Diazinon Water 7(l):73-84 Dieldrin Factors Influencing Residues 7(l):27-36 7(3/4): 122-126 7(3/4) ;165-180 7(3/4) :181-194 Humans 7(l):l-5 7(3/4) :122-126 Plants (other than those used for food and feed) 7(3/4) :205-213 Sediment 7(3/4) :165-180 Water 7(l):73-84 7(3/4):165-180 Wildlife 7(l):27-36 7(l):37-52 7(1):53-61 7(l):62-66 7(2):97-99 7(2):100-103 7(3/4) :153-164 7(3/4):165-180 7(3/4) :181-194 7(3/4):195-199 E Endosulfan Plants (other than those used for food and feed) 7(3/4) :205-213 Water 7(l):73-84 Endrin Plants (other than those used for food and feed) 7(3/4) :205-213 Water 7(l):73-84 Factors Influencing Residues Age mercury 7(3/4) :181-194 organochlorines 7(3/4) :181-194 PCB's 7(3/4) :181-194 Biological Magnification mirex 7(2):104-111 7(2);112-i:6 organochlorines 7(3/4): 165-180 Geographic Location mercury 7(3/41:153-164 7(3/4) :181-194 organochlorines 7(3/4) :153-164 7(3/4):181-194 PCB's 7(3/41:153-164 7(3/41:181-194 Habitat mirex 7(2):104-in Socioeconomic organochlorines 7(3/4): 122-126 PCB's 7(3/4) :122-126 Species mecury 7(11:27-36 organochlorines 7(l):27-36 PCBs 7(l):27-36 Food and Feed Dairy Products PCB's 7(2):95-96 Meat, Fish, and Poultry DDT 7(2):87-94 mercury 7(3/41:127-138 mirex 7(21:87-94 H Heptachlor/Heptachlor Epoxide Humans 7(l):l-5 Water 7(11:73-84 Wildlife 7(11:37-52 7(11:53-61 7(l):62-66 7(3/4) :153-164 7(3/4): 195-199 Pesticides Monitoring Journal Humans Adipose BHC/lindane 7(3/4) :122-126 DDE 7(3/4): 122-126 DDT 7(3/4): 122-126 dieldrin 7(3/4) :122-126 PCB's 7(3/4): 122-126 Milk organochlorines 7(I):|.5 PCB's 7(l):l-5 Lead Wildlife 7(l):67-72 Lindane, see BHC/Lindane M Malathion Water 7(l):73-84 Mercury Factors Influencing Residues 7(l):27-36 7(3/4):181-194 Food and Feed 7(3/4): 127-138 Soil 7(3/4) :214-2I6 Wildlife 7(l):27-36 7(l):37-52 7(l):67-72 7(3/4): 153-164 7(3/4) :181-194 7(3/4): 195-199 Methyl Parathion, see also Parathion Water 7(l):73-84 Mirex Factors Influencing Residues 7(2): 104-111 7(2):112-U6 Food and Feed 7(2) :87-94 Sediment 7(l):6-26 7(3/4): 144-145 Water 7(l):6-26 7(3/4): 144-145 Wildlife 7(l):6-26 7(2):100-103 7(2):104-111 7(2):112-116 7(3/4): 139-143 7(3/4): 144-145 7(3/4): 195-199 PCB's Factors Influencing Residues 7(l):27-36 7(3/4): 122-126 7(3/4):181-194 Food and Feed 7(2)95-96 Humans 7(l):l-5 7(3/4): 122-126 Water 7(l):73-84 Wildlife 7(l):27-36 7(l):37-52 7(l):62-66 7(2): 100-103 7(3/4): 139-143 7(3/4) :153-164 7(3/4): 181-194 7(3/4) :195-199 Plants (other than those used for food and feed) Tobacco organochlorines 7(3/4) :205-213 Polychlorinated Biphenyls, PCB's Sediment 2.4-D 7(3/4): 146-152 mirex 7(l):6-26 7(3/4): 144-145 organochlorines 7(3/4) :165-180 7(3/4) : 200-204 see Parathion, see also Methyl Parathion Water 7(l):73-84 Vol. 7, No. 3/4, March 1974 Silvex Water 7(l):73-84 Soil, see also Sediment General mercury 7(3/4) :214-2I6 Orchard organochlorines 7(3/4): 200-204 2,4,5-T Water 7(l):73-84 TDE (DDD) Factors Influencing Residues 7(l):27-36 7(3/4) :165-180 7(3/4) :181-194 Plants (other than those used for food and feed) 7(3/4) :205-2l3 Sediment 7(3/4) :165-180 Water 7(I);73-84 7(3/4): 165-180 Wildlife 7(l):27-36 7(l):37-52 7(1):53-61 7(l):62-66 7(2):97-99 7(2):10O-103 7(3/4) :153-164 7(3/4) :165-180 7(3/41:181-194 7(3/4): 195-199 7(3/4) ;200-204 Toxaphene Plants (other than those used for food and feed) 7(3/4) :205-213 Water 7(1):73-84 w Water, see also Sediment Canals 2,4-D 7(3/4) :146-152 Estuaries mirex 7(l):6-26 7(3/4): 144-145 Lakes organochlorines 7(3/4): 165-180 Rivers and Streams herbicides 7(l):73-84 organochlorines 7(l):73-84 7(3/4) :165-180 7(3/4): 200-204 organophosphates 7(l):73-84 PCB's 7(l):73-84 Wildlife Amphibians DDE 7(3/4) : 200-204 DDT 7(3/4) :200-204 mirex 7(2):104-111 TDE 7(3/4) :200-204 Birds arsenic 7(l):67-72 cadmium 7(l):67-72 2,4-D 7(3/4):146-152 DDE 7(3/4) :181-194 DDT 7(3/4) :181-194 lead 7(l):67-72 mercury 7(l):27-36 7(l):67-72 7(3/4): 153-164 7(3/4) :181-194 7(3/4): 195-199 mirex 7(l):6-26 organochlorines 7(l):27-36 7(2):100-I03 7(3/41:153-164 7(3/41:195-199 PCB's 7(2): 100-103 7(3/4): 153-164 7(3/41:195-199 TDE 7(3/4) :181-194 Birds' Eggs DDE 7(3/4):l81-194 DDT 7(3/4) :181-194 dieldrin 7(3/4):l8l-194 mercury 7(l):27-36 7(l):37-52 7(3/4) :181-I94 organochlorines 7(l):27-36 7(l):37-52 7(l):62-66 221 Wildlife— Cont. Birds' Eggs^i:ont. PCB's 7(l):37-52 7(3/4) ;181-194 TDE 7(3/4) ;181-194 Fish 2,4-D 7(3/4): 146-152 DDE 7(3/4) :I65-180 7(3/4) :200-204 DDT 7(3/4): 139-143 7(3/4): 165-180 7(3/4): 200-204 mercury 7(l);37-52 mirex 7(l):6-26 7(2):104-111 7(2):112-116 7(3/4): 139-143 7(3/4): 144-145 Wildlife— Cont. Fish — Cont. organochlorines 7(l):37-52 7(1):53-61 PCB's 7(l):37-52 7(3/4) :139-I43 TDE 7(3/4) :165-180 7(3/4): 200-204 Invertebrates (other than shellfish) DDE 7(3/4): 200-204 DDT 7(3/4); 200-204 mirex 7(2):I04-111 7(2):112-116 TDE 7(3/4): 200-204 Moose organochlorines 7(2):97-99 Wildlife— Cont. Raccoon mirex 7(l):6-26 Rodents mirex 7(2):112-116 SheUfish DDT 7(3/41:139-143 mercury 7(l):37-52 mirex 7(l):6-26 7(2):104-lll 7(21:112-116 7(3/4): 139-143 7(3/4) :144-145 organochlorines 7(l):37-52 PCB's 7(l):37-52 7(3/4) :I39-143 AUTHOR INDEX Andrews, F. L.. see Schulze, J. A. Armstrong, A. E., see Frank, R. Frank, R., Armstrong, A. E., Boelens, R. G., Braun, H. E., and Douglas, C. W. Organochlorine pesticide residues in sediment and fish tissues, Ontario, Canada. 7(3/4) : 165-180 B Bacby, J. R., see Savage, E. P. Belisle, a. a., see Blus, L. J. Benson, W. W., Watson, M., and Wvllie, J. Organochlorine Insecti- cide residues In wild moose, Idaho — 1972. 7(2):97-99 Blus, L. J., Belisle, A. A., and Prouty, R. M. Relations of the brown pelican to certain environmental pollutants. 7(3/4 ): 181-194 Boelens, R. G., see Frank, R. Borthwick, p. W., Duke, T. W.. Wilson, A. J., Jr., Lowe, J. I., Patrick, J. M., Jr., and Oberheu, J. C. Accumulation and move- ment of mirex In selected estuaries of South Carolina, 1969-71. 7(11:6-26 Borthwick, P. W., Cook, G. H., and Patrick, J. M., Jr. Mirex resi- dues In selected estuaries of South Carolina — June 1972. 7(3/4): 144-145 BouRKE, J. B., see KuHR, R. J. Braun, H. E., see Frank, R. Burns, J. E. Organochlorine pesticide and polychlorinated biphenyl residues in biopsied human adipose tissue, Texas, 1969-72 7(3/41:122-126 Gibson, J. R., Jones, G. A., Dorouoh, H. W., Lusk, C. I., and Thurston, R. Chlorinated insecticide residues in Kentucky burley tobacco: crop years 1963-72, 7( 3/4) :205-213 H Hawthorne, J. C, see Ford, J. H. Hawthorne, J. C, see Markin, G. P. Heath, R. G., and Hill, S. A. Nationwide organochlorine and mercury residues in wings of adult mallards and black ducks during the 1969-70 hunting season. 7(3/41:153-164 Hickey, J. J., see Faber, R. A. Hill, S. A., see Heath, R. G. HoiDEN, A. V. International cooperative study of organochlorine and mercury residues In wildlife, 1969-71. 7(l):37-52 HoRWiTZ, W., see Simpson, R. E. Hughes, D. L., see McLane, M. A R. Clark, E R., see McLane, M. A. R. Collins, H. L., see Markin, G. P. Cook, G. H., see Borthwick, P. W. D Davis, A. C, see Kuhr, R. J DE LA Cruz, A. A., see Naqvi, S. M. Dorouch, H. W., see Gibson, J. R. Douglas, C. W., see Frank, R. Duke, T. W., see Borthwick, P. W. Jones, G. A., see Gibson, J. R. K ICadoum, A. M., see Klaassen, H. E. Klaassen, H. E., and Kadoum, A. M. Pesticide residues in natural fish populations of the Smoky Hill River of western Kansas — 1967-69. 7(1 1:53-61 Kreitzer, J. F. Residues of organochlorine pesticides, mercury, and PCB's In mourning doves from eastern United States — 1970-71. 7(3/4): 195-199 Kuhr, R. J., Davis, A. C, and Bourke, J. B. DDT residues in soil, water, and fauna from New York apple orchards. 7(3/41:200-204 Faber, R. A., and Hickey, J. J. Eggshell thinning, chlorinated hydro- carbons, and mercury In Inland aquatic bird eggs, 1969 and 1970 7(11:27-36 Ford, J. H., Hawthorne, J. C, and Markin, G. P. Residues of mirex and certain other chlorinated hydrocarbon insecticides In beef fat— 1971. 7(2):87-94 Ford, J. H., see Markin, G. P. 222 LoNocoRE, J. R., and Mulhern, B. M. Organochlorine pesticides and polychlorinated biphenyls in black duck eggs from the United States and Canada— 1971. 7(l):62-66 Lowe, J. I., see Borthwick, P. W. Lusk, C. I., see Gibson, J. R. Pesticides Monitoring Journal M Malberg, J. W., see Savage, E. P. Manioold. D. B., see Schulze, J. A. Markin, G. p., Hawthorne, J. C, Collins, H. L., and Ford, J. H. Levels of mirex and some other organochlorine residues in seafood from Atlantic and Gulf Coastal States. 7(3/4) ; 139-143 Markin. G. P., see Ford, J. H. Martin, W. E., and Nickerson, P. R. Mercury, lead, cadmium, and arsenic residues in starlings — 1971. 7(l):67-72 McLane, M. a. R., Stickel, L. F.. Clark. E. R., and Hughes. D. L. Organochlorine residues in woodcock wings. 11 states — 1970-71. 7(2):IOO-103 Mulhern. B. M.. see Longcore. J. R. Savage. E. P.. Tessari. J. D., Malberg, J. W., Wheeler, H. W., anc Bagby, J. R. Organochlorine pesticide residues and polychlorinated biphenyls in human milk, Colorado — 1971-72. 7(1): 1-5 Schultz, D. p., and Whitney, E. W. Monitoring 2.4-D residues at Loxahatchee National Wildlife Refuge. 7(3/4) :146-152 Schulze, J. A., Manigold. D. B.. and Andrews. F. L. Pesticides in selected western streams— 1968-71. 7(l):73-84 Simpson. R. E., Horwitz. W.. and Roy, C. A. Surveys of mercury levels in fish and other foods. 7(3/4) : 127-138 Stickel, L. F., see McLane, M. A. R. N Naqvi, S. M.. and de la Cruz, A. A. Mirex incorporation in the en- vironment; residues in noniarget organisms — 1972. 7(2): 104-1 11 Nickerson, P. R., see Martin, W. E. NoRMENT, B. R., see Wolfe. J. L. Tai. H., see Wiersma. G. B. Tessari, J. D., see Savage, E. P. Thurston, R., see Gibson, J. R. o Oberheu, J. C, see Borthwick. P. W. Villeneuve. D. C, Reynolds. L. M., and Phillips, W. E. J. Residues of PCB's and PCX's in Canadian and imported European cheeses, Canada— 1972. 7(2):95-96 w Patrick, J. M., Jr., see Borthwick, P. W. Phillips, W. E. J., see Villeneuve, D. C. Prouty, R. M., see Blus, L. J. R Reynolds, L. M., see Villeneuve, D. C. Roy, C. A., see Simpson, R. E. Waison, M., see Benson, W. W. Wheeler, H. W., see Savage, E. P. Whitney, E. W., see Schultz, D. P. Wiersma, G. B., and Tai, H. Mercury levels in soils of the eastern United States. 7(3/4) ;2I4-216 Wilson, A. J., Jr , see Borthwick. P. W. Wolfe. J. L.. and Norment. B. R. Accumulation of mirex residues in selected organisms after an aerial treatment, Mississippi — 1971-72. 7(2):112-116 Wyllie, J., see Benson. W. W. Vol. 7, No. 3/4, March 1974 223 Information for Contributors The Pesticides Monitoring Journal welcomes from all sources qualified data and interpretive information which contribute to the understanding and evaluation of pesticides and their residues in relation to man and his environment. The publication is distributed principally to scientists and technicians associated with pesticide monitoring, research, and other programs concerned with the fate of pesticides following their application. Additional circulation is maintained for persons with related in- terests, notably those in the agricultural, chemical manu- facturing, and food processing industries; medical and public health workers; and conservationists. Authors are responsible for the accuracy and validity of their data and interpretations, including tables, charts, and refer- ences. Accuracy, reliability, and limitations of the sam- pling and analytical methods employed must be clearly demonstrated through the use of appropriate procedures, such as recovery experiments at appropriate levels, confirmatory tests, internal standards, and inter-labora- tory checks. The procedure employed should be ref- erenced or outlined in brief form, and crucial points or modifications should be noted. Check or control samples should be employed where po.ssible, and the sensitivity of the method should be given, particularly when very low levels of pesticides are being reported. Specific note should be made regarding correction of data for percent recoveries. Preparation of manuscripts should be in con- formance to the CBE Style Manual. 3d ed. Coun- cil of Biological Editors, Committee on Form and Style, American Institute of Biological Sciences, Washington, D. C. and/or the Style Manual of The United States Government Printing Office. An abstract (not to exceed 200 words) should accompany each manuscript submitted. All material should he submitted in duplicate (original and one carbon) and sent by first-class mail in flat form — not folded or rolled. Manuscripts should be typed on 8 1/2 x 11 inch paper with generous margins on all sides, and each page should end with a completed paragraph. All copy, including tables and references, should be double spaced, and all pages should be num- bered. The first page of the manuscript must con- tain authors' full names listed under the title, with aflSliations, and addresses footnoted below. Charts, illustrations, and tables, properly titled, should be appended at the end of the article with a notation in text to show where they should be inserted. 224 -Charts should be drawn so the numbers and texts will be legible when considerably reduced for publication. All drawings should be done in black ink on plain white paper. -Photographs should be made on glossy paper. Details should be clear, but size is not important. -The "number system" should be used for litera- ture citations in the text. List references in the order in which they are cited in the text, giving name of author/ s/, year, full title of article, exact name of periodical, volume, and inclusive pages. The Journal also welcomes "brief" papers reporting monitoring data of a preliminary nature or studies of limited scope. A section entitled Briefs will be included, as necessary, to provide space for papers of this type to present timely and informative data. These papers must be limited in length to two journal pages (850 words) and should conform to the format for regular papers accepted by the Journal. Pesticides ordinarily should be identified by common or generic names approved by national scientific so- cieties. The first reference to a particular pesticide should be followed by the chemical or scientific name in parentheses — assigned in accordance with Chemical Abstracts nomenclature. Structural chemical formulas should be used when appropriate. Published data and information require prior approval by the Editorial Advisory Board; however, endorsement of published in- formation by any specific Federal agency is not intended or to be implied. Authors of accepted manuscripts will receive edited typescripts for approval before type is set. After publication, senior authors will be provided with 100 reprints. Manuscripts are received and reviewed with the under- standing that they previously have not been accepted for technical publication elsewhere. If a paper has been given or is intended for presentation at a meeting, or if a significant portion of its contents has been published or submitted for publication elsewhere, notations of such should be provided. Correspondence on editorial matters or circulation mat- ters relating to oflncial subscriptions should be addressed to: Paul Fuschini, Editorial Manager, PESTICIDES MONITORING JOURNAL. Technical Services Divi- sion, Office of Pesticides Programs, U. S. Environmental Protection Agency, Room B49 East, Waterside Mall, 401 M Street, S.W., Washington, D. C. 20460. Pesticides Monitoring Journal BOSTON PUBLIC LIBRARY 3 9999 05571 195 4