1 > . i The Ontario Ministry of the Environment Scoring System A Scoring System for Assessing Environmental Contaminants Hazardous Contaminants Coordination Branch Ontario Ministry of the Environment January 1990 The Ontario Ministry of the Environment Scoring System A Scoring System for Assessing Environmental Contaminants Risk Identification Unit Hazardous Contaminants Coordination Branch Ontario Ministry of the Environment January 1990 lotrr Contents Preamble ii MOE Scoring System ^ ...^^.......^..............^^.^ ^.... 1 MOE Scoring System Summaiy Chart ^ 29 Appendix A - Guidelines for Using Score Qualifiers and Criteria A-1 Appendix B - Concern Levels for Promotion to the Ontario Effluent Monitoring Priority Pollutants List (EMPPL) B-1 -n Hi- Preamble There are thousands of chemical substances which can potentially be released into the various environmental compartments. It is not possible to evaluate the impact of all of these chemicals on the environment and on living organisms all at once. It therefore is helpful if a screening mechanism is developed to reduce to a manageable size the number of chemicals subject to monitoring and subsequent intensive examination and standards development. In this publication a method for scoring environmental contaminants is described, the objective of which is the relative assessment of chemical substances accord- ing to their ability to partition into multiple media, persist or bioaccumulate and/or have adverse effects on biota. Substances can then be screened or prioritized based on these scores. This scoring system is an adaption of the Vector Scoring System developed by the Ontario Ministry of the Environment for evaluating the exposure potential and toxicity characteris- tics of numerous chemicals. It is based on the use of a set of scoring parameters, each corresponding to a physical/chemical property or an effect which is relevant to the assessment of a contaminant's potential environmental or health effects. The scores assigned reflect the relative severity of effect associated with each parameter. Concern levels or cut-off scores may be set for some or all of the parameters such that those substances receiving scores equal to or above these concern levels would be desig- nated as being of particular concern. Priorities may also be assigned using combinations of scores or weighting of scores. The selection of the concern levels and the method, if any, by which the scores are combined or weighted depends on the needs of the user and the objec- tives of the particular program. As an example, the concern levels used for promoting substances to the Ontario Effluent Monitoring Priority Pollutants Ust are provided in Appendix B. The Ministry is currently using this scoring system as a basis for identifying chemicals for multimedia standards and water quality guidelines development, for selecting chemicals of high priority for air emission control (Clean Air Program - "CAP") and waste management (hazardous waste listing, Regulation 309), and for identifying chemicals for effluent monitoring purposes (Municipal-Industrial Strategy for Abatement - "MISA"). This system has also been adopted for use in the establishment of the Canada/U.S. Great Lakes Water Quality Agreement priority lists. For further information, please contact the Risk Identification Unit, Standards Develop- ment Section, Hazardous Contaminants Coordination Branch, Ontario Ministry of the Environment, 135 St. Clair Avenue West, Toronto, Ontario M4V IPS. i\ .. - 1 - ONTARIO MINISTRY OF THE ENVIRONfCNT SCORING SYSTEM INTRODUCTION The following generally accepteo parameters have been oevelopeo to oetermlne the concern level for a cheatcal In the environment* These parameters are a subgroup of the parameters In a methooology, oevelopeo for the Ministry of the Environment for assessing the relative environmental hazards of chemical contaminants* The magnltuoe of the score assignee to each parameter reflects the level of concern arising from that property of a chemical. 1« EnvlronMRtal Behaviour Parameters Range of scores: 0-10 for al I parameters a* to c* a) Environmental Transport b) Environmental Persistence c) Bloaccumulatton 2« Toxicity Parameter^ Range of scores: 0-10 for al I parameters a* to g* a) Acute Lethality b) Sub-Lethal Effects on Non-Mammalian Animals c) Sub-Lethal Effects on Plants 0) Sub-Lethal Effects on Mammals e) Teratogenicity f) Genotoxiclty /Mutagenicity g) Carcinogenicity In aodltlon to the numerical value asslgneo to a parameter, various symbols are useo to Inolcate special concerns regaruing the source of, or confluence in, the underlying oata: • If the oata required are not available, an asterisk (*) Is asslgneo to that parameter rather than a numerical score* if the oata useo are questionable (e*g*, data not completely meeting the specifications of a criterion, oata lacking In documentation, oata derived with outdated methods), a score Is assigned to the parameter, but It is "tagged* with a "Q" to Indicate doubt regarding the confidence In the data* An OKample of the use of this tag would be when saltwater species data was used In the absence of data for a freshwater species* '^; - 2 - If the oata used In the assignment of a parameter score Is "Ifmlteu", the score for that parameter Is "taggeo" with an "L". This Indicates that a score was assigned, but due to the nature of the readily available data, confidence In the score was less than If a more comprehensive data set had been used* In many Instances, additional data would either remove the "L" designation and confirm the score, or result In a higher score* •L" was also used If, In the absence of a freshwater fish BCF, log kow was used to score b I oaccumu I at ion* if the data used are perceived as representing a worst-case scenario (e*g*, toxicity data from Intravenous administration), the score for that parameter Is "tagged" with a "W". If the data used In the assignment of a parameter score are estimated from environmental modelling techniques or structure-activity relationships, the score for that parameter Is "tagged" with an "E"* These "tags" may be talien Into consideration when the chemical Is reviewed* ■' 0 ten ©-;• ■'A **+«*' PARAMETERS \jg^ Envlronwsnta! Behavfotir Parawwters - 3 - (•) ENVIRONMENTAL TRANSPORT 0? Rationale This parameter oescrlbes the transport of chemicals between environmental meota. The environmental transport of a chemical Is an Important factor In evaluating Its potential environmental ano health hazarus* Inter-meola transport can be observed ouring field studies or by undertaking microcosm studies In a laboratory, but relatively few substances have been studleo using such techniques* One way to estimate the environmental transport characteristics of a chemical Is to use a simple mathematical model such as the Fugaclty Level I model (MacKay and Peterson) • The Fugaclty Level I model estimates the equilibrium distribution of a chemical released to the envlroment. The environmental media considered are air, water, soil, sediment and aquatic biota* The model requires Information about the chemical's phystcochenlcal properties, l*e. molecular weight, solubility, vapour pressure, ana octanol-water partition coefficient* Soorlng Criteria The criteria for this parameter use results from environmental models* In audition, there are criteria for substances that are largely associated with fine particles (generally less than 10 um in size)* Examples are fine particles associated with Incinerator processes* - 4 - The scoring criteria for this parameter are as follows; PARAMETER SCORE CRITERIA 10 Three or more media each contaln_>_5? of the total amount releaseo 0|^ substance Is Inorganic and Is adsorbed to particles <10um fn diameter when releasee. 7 Two media each contain ^5? of the total amount released. 4 No one medium contains > 9^%, and only one medium contaIns^5]E of the total amount released* 0 Any single medium contains > 95} of the total amount released* Suggested Information Sources Lvman et al.. 1982 - A comprehensive reference of published values and estimation methods for various physical and chemical properties* Verschueren, 1983 - A handbook of environmental data for organic chemicals* ENVi ROTATE and I SHOW databases - Contain solubility^ vapour pressure* partition coefficients for many chemicals* ICF Inc., 1985 - Contains tabulations of physical, chemical and fate data for many organic substances ana elements* - 5 - Mills et al.. 1982 - A compilation of physical, chemical aiu fate iiata for many organic substances* Mackay ano Shiu, 1981 - A compilation of physical ano chemical parameters for organic substances* Kenaga ano Goring, 1980 - A ccmpM at Ion of solubility, sorption atu K^^ data* Clayton ano Clayton, 1981 - A comprehensive reference of Information on Inouslrlal chemicals* Karlckhoff, 1984 - Discussion of sorption processes In general anj K^^/K^^ values In particular* Amoore ano Hautala, 1983 • Information on volatilities of inoustrlal chemicals* Neeiy ano Blau, 1989 - Contains physical, Chemical ano fate oata ano estimation methoos* Cb) ENVIROWCNTAL PERSISTENCE Rationale This parameter oescrlbes the tenoeney for a chemical to persist In the environment* Substances In the environment can be subjecteo to a variety of processes Including sorption, oxioatlon, hyorolysis, photooegraoatlon ano blooegraoatlon* The net result of such processes may be expressed as the overall persistence of a substance In the environment* When quantified, persistence Is usually expresseo as the length of tlaw requlreo for one-half of the original amount of a substance to be degraded* It Is analogous to parameters which may be presented as "rate of loss In natural systems**, "overall half-life", or "5(tf recovery time"* It Is also similar to the "persistence" parameter calculated by fugaclty mooeis* Ha If- 1 Ives of chemicals may vary from seconos to thousanos of years (ICF Inc*, 1985)* Short half- lives generally tnolcate a lower level of concern* For exan^>le, envlronaental releases of substances with half-lives of less than a few oays often will not result In significant accumulation In the envlroment. Conversely, those with half-lives of several months or longer can leao to substantial exposure or accumulation In the fooo chain* - 6 - Scoring Criteria The criteria for this parameter are baseo on half-life values* If half- life oata are available, they vtll usually pertain to specific meola as opposeo to general environmental persistence* This Information provioes an Indication of levels of concern regarding specific media. In such cases. It Is recommended that the media providing the highest score be used* If persistence values have not been reported and cannot be estimated by using environmental models, other types of Information may offer guidance in developing a score for this parameter* For example, structure- activity relationships (SARs) may provide general Indications of persistence for relatively unknown substances structurally similar to more familiar substances* To assess the potential blodegradablltty of substances In wastewater treatment plants, test methods such as the statlc-culture-f lask and shaker-flask techniques have been used (for example, see Tabak et ,al*. 1981)* The results of these tests In general show good agreement with published work on blodegradabll ity* Substances not degraded under test conditions cannot be presumed to be Immune to microbial action In the environment* Accordingly, scores derived from SARs or blodegradabi tity tests should be tagged with E, Q, or W* PARAMETER SCORE CRITERIA 10 Half- life greater than 100 days 7 Half-life of more than 50 but less than or equal to 100 days 4 Half-life of more than 10 but less than or equal to 50 days 0 Half-life of less than or equal to 10 days S«i9g«st«u InfonMtlofi Sources - 7 - >t I "^'j '-^-p. I "KX/t ICF Inc.. 1985 - Incluoas compilation of half->ltves In several meola for organic substances* Milts et a!.. 1982 - Incluoes compilation of half-lives In aquatic meuta for organic substances* Verschueren, 1983 • Incluoes half*! Ives and blooegraoablllty test results for organic substances* fftCC - National Research Council of Cane(9a Associate Committee on Scientific Criteria for Environmental Quality - These publications Incluoe uata on blooegraoablllty for specific substances* ENV I ROTATE oatabase - '' Contains oata on blooegraoatlon rates for chemicals releasee to the envlroment* Tabak et al*, 1981 - Incluoes results of blooegraoablllty stuoles for more than 100 organic substances* Cc) BIOACCUMULATIOM Rationale This parameter oescrlbes the tenoency for a substance to acoMulate In biological systems* In the current conte)ct. the term bloaccumulatlon Is Intenoeo to convey the ability of a substance to accumulate in the tissues of organisms* Ihe tonoency for certain groups or classes of chemicals to bloaccumulate Is well oocumenteo* This process has also been referreo to as bloconcentratlon or blomagnlf Icatlon ano some authors have asslgneo various olstlnct oeflnltions to these terms but for purposes of this assessment those olfferences are relatively unimportant* One of the parameters frequently useo to express bloaccumulatlon Is the bloconcentratlon factor (BCD* Most BCF values pertain to fish or other aquatic organisms and are catculatao as the ratio of the concentration of a substance In the organism (or some specific tissue) on a wet weight basis to the concentration of the substance In the water af steady stata (Velth et al». 1980)* For organic substances, values of BCF range from about 1 to more than 1,000,000 (Lvman et al«. 1982)* Bloaccumulatlon factors have also been oetermlneo for some terrestrial vertebrates but these oata are less abunoant ano more olfflcult to locate than those for aquatic organisms* It is recommenoeo for this assessment that aafa collection efforts first focus on BCf values for aquatic organisms* - 8 - The tenoency of substances to bloaccumutate tn tissue frequently has been retateo to hyorophoblcJty or llpophll Iclty (Velth et ai. 1980). As a result, various regression equations have been suggested for preolctfng BCF values for aquatic organisms baseo on the octanol-water partition coefficient (Kq^) and other physico-chemical properties. To oate, those that use Kq^ values have been the most wtiiely Investtgatsa ano most successful (Lvman et al«. 1962; Gever et al>, 1984)* Scoring Crtteria Scoring criteria for this parameter are oaflned In terms of either BCF or log K^^* The correlation between the two sets of criteria Is based upon the following relationship oevelopeu from experimental oata on 84 chemicals (Velth et al«. 1980): log BCF • 0.76 log K^^ - 0.23 Other equations have been developed baseo upon various groups of chemicals. If an equation Is available that Is more directly applicable to a substance being evaluated, that equation can be used. The btoaccumulatlon of compounds with relatively high K^ values Is Influenced by the degree to which a compound dissociates In water. Equations for estimating b I oac cumulation that Include a dissociation term have not been reported. For this parameter, dissociation has not been considered In the determination of scores. This should tend to produce somewhat higher scores than warranted for some organic substances. BCF values can be estimated only to within an order of magnitude using most of the correlations developed to date, and laboratory test situations are Incapable of duplicating field situations (Lyman et al.. 1982). Therefore, the consideration of dissociation effects may be unimportant, for this evaluation. If scores based on both the BCF and the K^^ can be determined, preferenoa should be given to the measured BCF values rather than those estimated baseo on K^^. PARAMETER CRITERIA SCORE , BCF loo Kow to >15000 >6.0 7 >500 - 15000 >4.0 - 6.0 4 >20 - 500 >2.0 - 4.0 0 < 20 < 2.0 - 9 - S«99MtM InfonMtiofi Sources Lvtnan et el., 1982 - Contains BCF anu K^^ oata and estlnatlon mattoos. G»yer et al«. 1984 - Examines relationship between BCF amj K^^* Kenaga ano Goring, 1980 - Induces K^^ and BCF data for aquatic ewiroments* Verschueren, 1983 - Includes BCF and K^^ data for organic substances* Velth et al.. 1980 - Includes BCF anu K^^ values. AQUIRE database - Contains BCF data for aquatic organlsas* Mackay« 1982 - Exanlnes correlations of BCFs. Garten and Trabatka* 1983 - Contains BCF data for data for aquatic and terrestrial organlsns< ICF Inc., 1985 - Includes BCF data* Hansch and Leo, 1979 - Describes how to estlaMte Kg^ values* 2* Toxicity Paraweters Parameters "a" through "h" were selected to describe the toxicologlcal properties of chemicals* Information on acute lethality of chemicals to all targets In the environment Is Included In parameter "a". The sub-lethal effects of chemicals on ecological systems (plants and animals) are described In parameters "b" and "c"* Parameters "d" through "f" are primarily designed to describe potential adverse effects on human health* - 10 - When oata are lacking on the effects of a chemical on a specific environmental target (e.g., humans, fish or wildlife) the best available Information shoulo be usee. Unless specific oata are available on species differences In responses to the chemical. It Is assuroeo that all species respond In an equivalent manner and the most sensitive would be used In scoring. Differences In response among species, or other differences between experimental ano Veal-worio" exposure situations (e.g., data from high level experimental exposures extrapolated to much lower levels) are not considered In this assessment* ■'■■ fi#*»^*t«>' There are several general topics. Including route and duration of exposure and validity of testing procedures, that apply equally to al I of the foxictty parameters. These are discussed below and will only be briefly referred to In the descriptions of each parameter. Route of Exposure Route of exposure Is an Important factor In the Judgement of the appllcablf Ity and validity of the effects observed under controlled experimental conditions (Grice, 1984; WII les et al». 1985). In terrestrial animals, oral. Inhalation and dermal routes of exposure we considered the most representative of '*real**wortd" exposures* In aquatic species, the usual route of exposure Is through water* In plants, exposures usually occur through soils or from the atmosphere* In all test systems, data derived by direct application of chemicals to biological systems (e.g., direct Injections Into tissues) that by-pass normal Absorption and uptake systems may Indicate the potential for the production of adverse effects but their relevance to normal exposures should be carefully evaluated. In addition, the use of vehicles (e.g., dimethyl sulfoxide) In oermai exposure studies can substantially Increase the uptake of chemicals through the skin and, although the results would Indicate a worst-case assessment of potential effects, their relevance to usual dermal exposure is questionable* in all of the toxicity elements the scorer must exercise Judgement In the use of data derived frcm unusual exposure routes. If such data are the only Information available they may be used, but, at the very least the scores assigned require appropriate "flags" 0.5 - 5 >0*5 - 5 >1*5 - 15 >0*1 - 1 6 >5 - 50 >5 - 50 >15 - 150 >1 - 10 4 >50 - 500 >50 - 500 >150 - 1500 >10 - 100 2 >500 - 5000 >500 - 5000 >1500 - 15000 MOO - 1000 0 >5000 >5000 M5000 >1000 SMggMt«(i InfonMtlOA Sources - 13 - ACQUIRE «Mtabas« - This oatabase contains acute lethality values for aquatic ana terrestrial species* Hayes, 1982 - Contains tnforaatton on the toxicology of pestlctoes and assoclateo chemicals with particular reference to effects In humans* Ketehen ano Porter, 1979 - These Critical Material Data sheets sumnarlze Information on the toxic potential of indtvluual chemicals. Including acute lethality oata. In terrestrial species* nercK i noex ' The Merck index lists Inotces of toxicity for many chemicals In terrestrial species* HEDLINE uat^ase - A computerized database presenting titles and abstracts of piibllshed, worl(iHloe« biomedical literature* Cteyton & Clayton, 1981 • Summarizes the toxic characteristics of a large nuaber of Induslrlaf chemicals, primarily \fi terrestrial species* (b) SUB-LETHAL EFFECTS ON NON-MAffW. I AN SPECIES Rationale This parameter describes potential effects from long-term exposures of non-mammalian species to chemicals* The effects-data may be expressed as median effect concentration (ECijo), maximum aquatic toxic concentration (MATC) or nc^obsenfed-auverse-effect-conoentr at Ion (NQAEO* The most frequently reported data of these types are EC^o values for fish or other aquatic organisms such as daphnia* Associated with an EC5() value Is the species studied, the endpolnt(s) observed, and the duration of exposure* Common endpolnts are immobilization, loss of equilibrium, effects on reproduction and other sub-lethal effects* As with other parameters, if different Indicators of effects vre available, the most sensitive would be used, unless scorer Judgement Indicates otherwise* As with mammalian toxicity, duration of exposure Is Important to the Interpretation of the results* For aquatic organisms, either full or partial life-cycle tests ar^ qreferreii for the - T4 - assessment of reprouucttve effects* Such tests may last as few as seven uays or extenu beyono a year oepending on the life cycle* For tarreslrlal animals, perlous of exposure usually last several months* For other types of effects, results from 96-hour exposures generally have more creoence than shorter exposures* In aooltlon, preference should be given to tests on freshwater species native or Introduceo to North America* Scoring Criteria , ^ ^^ Based on published results of the effects of many substances on aquatic organisms, the NOAEC values that appear In the score definitions ore a factor of 100 lower than EC^q values (Koneroann and VIsser, 1983)* Maximum Aquatic Toxic Concentration (MATC) values are 10 times lower than EC5Q values* The scoring criteria for this parameter are as follows: PARAMETER SCORE CRITERIA » AQUATIC ORGANISMS TERRESTRIAL ORGAN I SMS 10 EC5ojcp*02 mg/L; OR MATC^*002 mg/L; OR NOAEC 40*0002 rag/L In different genera* Adverse effects atjcj mg/kg for sub- chronic exposure 0R^*5 mg/kg for chronic exposure. In different genera* EC2Q^*02 mg/L; OR MATC ^.002 mg/L OR NOAEC^.0002 mg/L In one ganera only* Adverse effects et_<1 mg/kg for sub- chroolc exposure OR ^.5 mg/kg chronic exposure. In one genus only* EC50 <0*2 - 0*02 mg/L; OR MATC <0*02 - 0.002 mg/L; OR NOAEC <0*002 - 0*0002 mg/L* Adverse effects at >I-10 mg/kg for sub-chronic exposure OR >0*5-5 mg/ kg for chronic exposure* EC50 *2 - 0*2 mg/L; OR MATC <0*2 - 0*02 mg/L; OR NOAEC <0*02 • 0*002 mg/L. Adverse or non-adverse effects at >10-100 mg/kg for sub-chronic exposure OR >5-50 mg/kg for chronic exposure* EC50 <20 - 2 mg/L; OR MATC <2 - 0.2 mg/L; OR NOAEC <0*2 - 0*02 mg/L* Adverse or non-adverse effects at >100-1000 mg/kg for sub-chronic exposure OR >5 0-500 mg/kg for chronic exposure EC5o_>20 "»3/L; OR MATC 2. 2 mg/L; OR NOAEC 2P-2 mg/L* Adverse or non-adverse effects at ^000 mg/kg for sub-chronic exposure exposure, ^00 mg/kg for chronic e)^3csire - 15 - SuggestM Infonutten Sources AQUIRE database - AQUIRE has EC5Q ano/or NO\EC uata for aquatic organisms for some organic chenlcals* Most tnfonsatton requfreo for this element must be sought from prfmary sources loentlfleu through literature searches* Co) SUB-LETHAL EFFECTS ON PLAWTS RatloMifa Sub-lethal effects on plants are highly varleo oepenilng on the toxicant* The relative significance of the lr\]ury or effect uepenos on the coaunootty ana Its use* These can be ulvloed Into three categories* A - The appearance Is Important, but growth ano yield are of much less Importance* This Is relevant for ornoaentals, flower crcps, leafy vegetables ana fruit* B The Impact on growth and yield are the most significant, and visible Injury to the foliage, though unsightly. Is of less Importance. This Is relevant for vegetables, fruits, seeus and storage organs such as tubers* C There are no visible tf\|urlous effects but the longevity of the commodity has been altered* This Is of greatest significance In flower crcps and storage of fruit and vegetables* The tOKtc effects can generally be assayed using short term tests with Indicator plants* The possible effects Include a wide spectrum of responses: Inhibition of germination. Inhibition of seedling growth, growth abnormalities, reduction In either root or shoot growth, etc* Long term tests with annual plants may be used to assess chronic effects such as decreased yield or decreased competitiveness (NAS, 1975)* The most commonly tested aquatic plants are algae and duckweed (Lemna minor) (U«S* EPA, 1978)* Several test methods have been developed that use algae (for eKample, the U*S* EPA Algal Assay Bottle Test). Duckweed has been used to assess the effects of substances on aquatic macrophytes, (EPA, 1978)* Effects on the genetic make up of the organism may be assayed using other short term tests with plant material* These Include gene mutations, ONA repair, primary ONA damage anj chromosomal abberatlons (Sandhu, 1980). Some examples of genetic mutation assays using plants are the measurement of chromosomal aberrations In root tip cells, the Tradescantia microoucleus assay - 16 - (Sanohu, 1980) ano the use of Arab I oops 1 s for measuring the frequency of mutat tonal events at the embryo stage (Reuei, 1980). Scoring CrtterU The score oeflnftlons for aquatic plants are very similar to those usea In parameters which aooress sub-lethal effects on aquatic animals* Various btomonltors have been useu for olfferent contaminants with each species displaying characteristic symptoms for a given pollutant. Some of these tests have been stanjarolzeo to a substantial oegree while others are only qualitative Indicators* Stanoarulzeo sampling methods have also been uevlsed for substances that accumulate In vegetation ana that are toxic to animals* Lichens are also used for a variety of contaminants, both as Indicators by presence or absence, or are used as accumulators* Standardized tests have been reported for relatively few substances* In some cases, the scoring system can accannodate results expressed In concentration units (mg/L for substance In water, mg/ar for gaseous contaminants, and mg/kg for substances In the soil), but In most instances, the length of exposure time Is very Important* It Is thus necessary to link the persistence or the number of releases or the length of exposure to this element In some way through the use of appropriate combining rules*' Precautions,* Soil extraction procedures are critical In determining the level of a toxicant, e*g* the total amount removed by acid extraction may no be meaningful In relation to plant bioavailability. - 17 - The scoring criteria for this element are as follows: PARAhCTER SCORE ICDIUM»« CRITERIA* <5% EFFECT OR NOAEL >5-50S EFFECT OR EC50 >50% EFFECT 10 WATER <0.001 AIR & SOIL <0.01 KfATER 0.001-0.01 AIR & SOIL 0.01-0.1 WATER >0.01-0.1 AIR & SOIL >0.1-1 WATER >0.1-1 AIR i SOIL >1-10 WATER >1-10 AIR & SOIL MO-100 WATER >10 AIR & SOIL >100 <0.01 <0.1 0.01-0.1 0.1-1 >0.1-l >1-10 >1-10 >10-100 >1 0-100 >1 00-1 000 >100 >1000 <0.1 <1 0.1-1 1-10 >1-10 MO-lOO >1 0-100 >10O-100O >1 00-1 000 >1 000-1 0000 >1000 > 10000 •Effects consioereo; Reouction In gro«»th, total btoroass or photsynthesis •^Unlts: Water - «g/L Air - mg/m' Soil - mg/kg Suggesteu Infonaatlon Sources Manning ano Feijer, 1980- Dlscusses the use of plants as monitors of pollution* - 18 - Lepp, 1991 - Ofscussas effects of heavy metals in plants* Martin a no Cough trey, 1982 - Discusses effects of heavy metals on biota as Inufcatators of pollution. NRCC - Publications of the Associate Committee on Scientific Criteria for Environmental Chemistry Inctuoes oata on effects on plants* Levitt, 1980 - Reviews environmental stress on plants* Ormroo, 1978 - Reviews effects of pollution on horticulture. Information will have to be sought from primary sources for many of the toxicants. (0) SUBM-ETtiAL EFFECTS ON MAMMALS Rationale This parameter oeserlbes potential longer-term effects of chemicals In mammals. The effects are olrecteo primarily at human health, although the actual li^fa useu will largely be from laboratory animals* Other scoring systems (see Hushon ana Kornrelch, 1984) general ly score chemicals for sub- lethal toxicity baseo on specific effects (e*g*, separate scores for carcinogenicity, mutagenicity, teratogenicity, etc*), but most oo not aooress systemic toxic effects. The toxic effects Incluoeo In this parameter we restrlcteo to sub-lethal systemic effects, but oo not Incluoe carcinogenic, mutagenic or terafogenlc effects since these are Incluoeo In other parameters. Scoring Criteria If oata are not available on the effects following a suitable ouratlon of exposure, either - 19 - appropriate "tags" (W, 0 or E) shoula bo usea, or, preferably, the criteria shoulu be olvloeo by an appropriate extrapolation factor to aojust for potential effects that woulo not oevelop curing shorter exposure stuoles. Criteria useo In the jevelopment of scores for this parameter woulo be oerlveo from sub-chronic (general ly 90-oay exposure) or chronic (usual ly 1 year or more) exposure stuoles In any mammalian species (refer to the general olscusslon of exposure ouratlon). If the oata were oerlveo from sub-chronic stuoles. It is reccmmenoeo that the NOAEL be oivloeo by a 10-folo extrapolation factor (see FDA, 1982; Dourson ano Stara, 1983). If the only oata available Involveo even shorter term exposures (e.g., 14 oays). It Is reccmmenoeo that a lOO-folo extrapolation factor be useo* (k}nsIoerable Juogement will be requtreo In the utilization of such extrapolation factors, constoering Issues such as the biological half-life of the chemical, the biological characteristics of the test system from which the oata was oerlveo, ano knowleoge of the usual consequences of the type(s} of lesions proouceo* The scoring criteria for this parameter oo not provloe for oifferences In the type of toxic response observeo* For ocample. If the effects associ ateo with ocposure are Irreversible, the consequences of exposure are much more serious than If the effects reverse following cessation of exposure* For the purposes of this assessment, all effects are consioereo as equal but oetalls of uifferences In the severity of the effects woulo be carefully noteo* Examples of the various en«i-poInts Incluoeo as chronic systemic effects are as follows: Reproouctlon toxicity • Aoverse effects on reproouctlon as they affect the survival, oevelopment ano well-being of the species, Inciuoing Interference with gonaoat functions but excluoing teratogenic effects* General toxicity - (general oepressions In booy weight ano booy weight gains, general behavioural alterations ano Increases in olseases seconoary to Chen lea I exposure* - Gross or microscopic alterations I no I cat I ve of olsease from toxic events* - Aoverse or oeleterlous effects on organ systems or functions, alterations In secretions of exocrine ano enoocrlne glanos, alterations In the brain ano peripheral nervous systems* - Treatment relateo biochemical effects* If oata are available on more than one of these effects, the effect occurring at the lowest exposure level in the most sensitive test system shoulo be useo in scoring* In aooltton. - 20 - structure- activity relationships may provloe estimates of the occurrence of chronic effects If oata on the actual ccmpouno are lacking. Structure-act Ivl ty relationships appear reasonably preolctlve for certain types of effects (e.g., narcotic effects), however, little preolctive value Is obtalneo for other effects using available methoos. In the future, the accuracy of structure- activity relationships In preolcting effects between olfferent chemicals may Improve. Even with present methooologles, however, an estimation of potential effects may prove more valuable than accepting a Juogement of Inaoequate Information. Such estimates, however, would be appropriately "flaggeo** with a Q or E. The scoring system for this parameter is as follows: PAR/WCTER SCORE criteria' oral noael mq/kq INHALATION NOAEL wq/nr 10 <0.1 <0.3 >0.1 - I >0.3 - 3 >t - 10 >3 - 30 >10 - 100 >30 - 300 >100 - 1000 >1000 ,'^rtui >300 - 3000 >3000 Criteria are baseo on uata from exposures of 90 uays or more In curat Ion. If uata from stuoles of 28-<90 oays ouratlon are useu, ulvlue the oata values by 10. If oata fran stuol< of <28 oays ouratlon are useo, olvloe the oata values by 100. Suggestoo Information Sources Most of the Information on the toxic effects associated with chronic exposure to chemicals woulo be obtalneo from original scientific publications which coulo be accessed through the I^DLINE ano TOXLINE oatabases. Aoottlonal sources of summary oata Incluoe Ketchen ano Porter (1979), Clayton ano Clayton (1981), RTECS oatabase, ano Verschueren (1983). It shoulo be emphasized however, that the Juogement of the vallolty of a NOEL from summary oata is difficult and that original publications should be consulted* - 21 - Cf) TERATOGEWtCITY fUtlonal* Thts parameter describes the potential teratogenic effects of chemicals on mammalian systems. Toxic effects on reproouctlon In plants, non-mamma 1 1 an and mammalian systems, as olstlnct from oevelopmentai defects, are described In parameters b, c, ano d» The production of terata by exposure to chemical contaminants can seriously compromise the development ano survival of offspring. Such effects are usually Irreversible, although curnent understanjlng Is that they have an exposure threshold (EPA« 1984). The criteria for these effects are as outlined by the U.S. Environmental Protection Agency (EPA, 1984)* Teratogenic effects Include frank developmental malformations detrimental to the survival, future development, or well-being of newborn. They do not Include oevelopmentai anomalies and aberrations that appear to be secondary to embryo-, feto- ano maternal toxicity (see EPA, 1984; Khera, 1981 )• Many such effects are known to recover as development proceeds (e.g., reversible delayed ossification of various parts of the skeleton, delayed development of specific organs, delayed eye opening, delayed vaginal opening, reduced body weight) (Khera, 1981)* In some cases, exposure of pregnant females to chemicals can result in malnutrition oue to decreased feed Intake* Malnutrition has been shown to delay embryo ano fetal development, reduce birth weights ano. In severe cases, produce Irreversible neurological and metabolic abnormalities (EPA, 1984; Khera, 1984). These differences In the apparent severity between frank terata and minor developmental anomalies fron chemicals are reflected In the scoring criteria for thts element. Behavioural teratology Is a rapidly developing sub-fTeid of teratology and Includes effects related to alterations In the behaviour of the offspring as they mature. In some cases behavioural effects may not be evident until maturity (e.g., effects on sexual behaviour). Other effects may only be temporary and actual ly disappear af some later stage of development, tto specific criteria have been Included In this parameter for behavlotral teratogenic effects and judgement must be exercised to determine how such effects "fit" into the criteria provioeo. As the significance of such effects Is better understood, alterations In +he criteria for this parameter may be required to encompass the Increase In knowledge. Scoring Criteria Working fron the assumption that teratogenic effects exhibit exposure thresholds (Khera, 1981; EPA, 1984), scoring criteria are based on gradations In exposwe levels associated with effects. Since teratogenic effects ere viewed as more serious than developmental anomalies as outlined above, higher scores are applied to chemicals showing evidence of frank teratogenicity. Chemicals producing developmental anomalies ano aberrations ere assigned lower scores (e.g., delayed - 22 - ossification of t>one, (Jecreased fetal weights, decreased birth weights, prolonged gestation, decreased survival without abnormalities, developmental effects that reverse during postnatal deve lopment). Duration of exposure Is particularly critical In assessing teratogenic effects. To adequately assess the potential for such effects from a chemical exposure should occur at least through the period of organogenesis (e.g., usually from late In the first trimester through early In the third trimester of gestation). In addition, the levels of exposure studied should be sufficient to elicit a range of effects In the dams, from toxicity at the higher exposures to no-observable effects at the lower exposures (Grice et a l« 1975; EPA, 1984; Khera, 1981), The general requirements regarding route of exposure dlsojssed earlier also apply to teratogenicity assessments* The scoring criteria for this parameter are as follows: PARAMETER o & SCORE CRITERIA 10 - Teratogenic effects observed without overt maternal toxicity at maternal expos ures j^ • 1 mg/kg/day during organogenesis, or equivalent exposure^ 8 - Teratogenic effects observed without maternal toxicity at maternal exposures >0«1 • 1 mg/kg/day during organogenesis or equivalent exposure 6 - Teratogenic effects or developmental anomalies observed at maternal exposures >1 - 10 mg/kg/day during organogenesis or equivalent exposure 4 • Teratogenic effects or developmental anomalies observed at maternal exposures >10 - 50 mg/kg/day during organogenesis or equivalent exposure ' 2 - Teratogenic effects or developmental anomalies obsreved at maternal exposures >50 - 1000 mg/kg/day during organogenesis or equivalent exposure 0 - No terata observed, or observed only at maternal exposures of ^000 mg/kg/day or equivalent exposure ' Equivalent exposure by Inhalation or dermal routes, assuming lOOj absorption and that effects after dermal exposure would occur at oamparable doses to oral exposure. Total dose via Inhalation Is to be converted to an approximate dally oral dose equivalent b/ the use of appropriate facfors (e.g. ppm-to-mg/m^ conversion factor and physiological standards such as: a 60 kg adult human respires 20 m^ of air per day; a 275 g female rat respires 0.17 m^ of air per day)* - 23 - InforiMtton Sources Most of the Information on the teratogenic effects assoclateu with exposure to chemicals can be obtalneu from original scientific publications which can be accessej through the MEDLINE ano TOXLINE databases. Aooltlonal sources of summary oata Incluoe Ketchen ano Porfer (1979), Clayton anu Clayton (1981), RTECS oatabase, and Verschueren (1983). Care should be exercised In using the RTECS date base since only studies showing positive effects associated with exposure are reported. It must also be emphasized that the judgement of the validity of teratogenic effects Ce.g., the evaluation of frank developmental anomalies versus developmental aberrations) from summary data Is difficult and that original publications should be consulted. GENOTOX I C I TY/MUTAGEW I CI TY Rationale This parameter describes the mutagenic and genotoxic potential of a chemical. Such effects In themselves ere Indicative of potential hazards of chemicals to health anu the environment. In addition, the strength of such evidence is valuable In the Interpretation of other potential hazards from chemicals (e.g., carcinogenicity). Genotoxic or mutagenic effects on somatic or germ cells are considered equal potential hazards* Evidence of heritable nutations (i.e., mutations In germ cells) was regarded as more indicative of the test system studied and ability of a chemical to distribute to germ celts (i.e., the disposition of the chemical In vivo) rather than of a greater potential hazard. In addition* assessment of the potential for germ cell mutations requires specific tests (e.g., dominant lethal test, mouse heritable translocation assay) and results fran such tests are not available for large numbers of chemicals. Therefore, specific scoring criteria for germ cell mutations would Increase the dependency of the resulting prioritization of chemicals on the Information available rof^r than Indicators of potential hazard. In the scoring criteria used, chemicals for which evidence of germ cell mutations are available would receive high scores, however, not preferentially higher than chemicals with evidence of somatic mutations only. Scoring Criteria The criteria assign higher scores to chemicals with adequate evidence of mutagenlc/genotoxlc effects derived from short-term tests. The primary objective Is to score the potential of a chemical to produce such effects. Chemicals producing direct mutagenlc/genotoxlc effects In the absence of overt toxicity are assigned the highest scores (e.g., the chemical or Its activated metabol I te(s) directly acts on genetic material to produce mutations or genotoxic effects). Clastogenlc effects produced by - 24 - chemicals that uo not olrectly Interact with genetic material sre scorea In the next category. Chemicals causing mutagenic or genotoxic effects Inulrectly by Interfering with various cellular systems woulo receive lower scores. Scores of two or four shoulo be asslgneo to chemicals having positive evidence from certain test systems but clear evloence of lack of effects In other test systems. It Is assumeu that at I test oata will be oerlveo unoer optimal experimental conoltlons (e.g., using valloateo test proceoures, Incluoing appropriate S-9 metabolic activating systems, aoequately controlling for unusual chem I cat /physical characteristics of the test chemicals). Acceptable tests Include, but are not necessarily llmlteo to, the following: •^ I" vitro gene mutation Salmonel la/mammal Ian microsome assay CHO/HGPRT - assay L5178Y TK - assay Haplolo Saccharomyces assay b) In vitro mammal Ian chromosomal aberrations metaphase analysis In mammalian ceils exposeo In vitro (not Inducing sister chromatic exchange ano micrpnuclet) ^^ In vivo mammalian chromosomal aberrations rooent bone marrow micronucleus assay recent bone marrow metaphase analysis (not Inducing sister chromatic exchange) c) In vivo mammalian gene mutation or Indicator tests In a seconc somatic tissue rocent liver unscheculec ONA synthesis rocent sister chromatic exchange Data from other tests may be usee with appropriate justification. There wilt be many chemicals for which adequate Information for this parameter Is lacking or Incomplete. The use of structure- activity relationships In ceveloping scores for this parameter may be a viable alternative In the future, however, at present such concepts are only In their formative stages (FDA, 1982; NIP, 1984; OSTP, 1985) Consequently, conslcerable expertise anc Jucgement are required to assign scores based on structure-activity Information, and such scores would require appropriate "flags" to signify the level of conflcence In the cata usee (e.g., W, Q, E). - 2r- The scoring criteria for this parameter are as follows: PARAMETER SCORE CRITERIA ■-»«ot>- 10 Conclusive evioence of mutagenicity or genotoxiclty In recognlzeo prokaryotic or eukaryotic test systems at exposure levels not producing overt toxic effects (In vivo anu In vitro eukaryotic oata are positive or are absent)* 8 Evioence of clastogenlc effects (general DNA uaroage, strand breaks, sister chromatid exchange). Intercalations or crosslinks but no evidence of Increased Incidences of nutations or direct Interactions with genetic material 6 Does not Interact directly with DNA, but Interferes with cellular mechanisms such as ONA synthesis and DNA repair. Effects may be observed at exposure levels associated with overt toxicity unrelated to genetic effects 4 Mutagen/genotoxtn In prokaryotic systems only; In vitro eukaryotic data CKlst, and the results are negative. 2 Mutaqen/qenotoxin In vitro only; In vivo data exist, and the results ar9 negative. 0 No evioence of mutagenic or genotoxic effects In a adequate battery of test systems* Suggested InforaatloN Sources Information on the genotoxlclty/mutagenlelty of chemicals would generally be obtained frcm original publications and review articles as loentlfleo through MEDLINE or TOXLfNE databases or through the GenTox Information Service* Information may also be available frcm various summary data sources Including Bowman (1982), Falrchlld (1978), Ftshbein (1979), Ketchen and Porter (1979), Klrsch-Voloers (1983), Sax et al. (1981), Soderman (1983), Sontag (1981), and Stich and San (1984). It Is difficult to Judge the validity of genotoxlclty/mutagenlelty tests from summary data, however, and original publications should be consulted where possible. (g) CARCINOGENICITY Rationale This parameter describes the potential of chemicals to cause cancer. Detailed assessment of the - 2<- dose-responso relattonshlps, types of cancers proouceo, the validity of extrapolating carcinogenicity oata among species ano the processes of risk loent if Icatlon, assessment ana management are beyonu the sophistication of this assessment* There Is general agreement that raalatlon, biological, physical and chemical agents can cause cancer* In addition, the biochemical and molecular process of cancer development, as It Is understood. Is similar among mammalian species (N7P, 1984; OSTP, 1985). It Is evident that the development of cancer Is a multi-stage process Involving Interactions of agents with genetic material (the genome). The Induction of tumor I genie phenotypes through Interactions with the genome may occur directly through the Induction of somatic mutations or Indirectly by alterations In gene expression* A number of factors affect the occurrence of these events. Including age, sex, genetic differences, strain and species differences, diet, dose rate, route of exposure. Interactions with other agents and a variety of environmental conditions (NTP, 1984; OSTP, 1985)* Furthermore, the production of these effects by a chemical may be by direct action of the chemical or Its metabolites (e*g*, direct acting, genotoxic carcinogens) or indirect through actions of the chemical on systems that secondarily produce tumorlgentc phenotypes (e*g*, non-genotoxic or ep I genetic mechanism)* Although the detailed mechanlsm(s) of cancer production are not fully understood. It Is evident that once the required modification In the genome occurs (known as Initiation), the process Is Irreversible and self-propagating* A wide range of factors affect the Initiation process, however, and many of these are believed to be reversible (IRL6, 1979; NTP, 1984; OSTP, 1985) • Although the exact mechanisms of the various stages of carcinogenesis are not fully understood, it 'Is apparent that the events leading to the Initiation of cells are dose-relatad (l*e*, the frequency of occurrence of Initiation increases with exposure)* Once Initiation has occurred, however, the subsequent development of tumours Is Independent of the exposure level (IRLG, 1979)* This Information Is important to the scoring of the carcinogenic potential of a chemical* Based on this brief summary of what Is known about the process of carcinogenesis (refer to IRL6# 1979, NTP, 1984 and OSTP, 1985, for more detailed discussions), the scoring criteria for this element differentiate between direct acting and Indirect acting carcinogens* It Is Important that the scoring system not merely reflect the completeness of the data base (e*g*, only a few chemicals have been adequately studied from an epidemiological point of view In human populations to assess their carcinogenicity). For many chemicals, epidemiological studies to assess their carcinogenic potential will never be conducted and complete reliance will have to be placed on animal bioassay data for their evaluation* If the data from animal btoassays are viewed sufficiently strong, "epidemiological ly proven" and "potential human" carcinogens (l.e, positive in animal bloassays) are given equal weight in the scoring system. - 27 - Scoring Critorta The following oefinftlons of carcinogenicity are useo In scoring this parameter (Tcrtatls, 1979): •• EvToence of carcinogenicity Is positive when an Increase In malignant tunours Is causeo In more than one species or strain. In multiple experiments wttti varying routes or levels of exposure or to an unusual degree with respect to type, site, Incloence or latency perloo* • Evidence of carcinogenicity Is negative when no tumour Induction Ts observed In at least two adequate and appropriate animal studies In different species or In both animal and epidemiology studies* Evidence of carcinogenicity Is inconclusive when neither of the above two conditions apply, usually because the observations are Inadequate, of unacceptable quality or excessively limited* Contradictory results from different test systems may also lead to an Inconclusive ' assessment* Such conditions ar9 recorded as either positive or negative for carcinogenicity and tagged with either Q or W depending on the Interpretation of the Information by the scorer* There Is a great deal of controversy regarding the potency ranking of carcinogens, particularly when attempting to denote the potency of a chemical to cause cancer In man from data Oerlved frcm animal cancer bloassays* Animal bloassays utilize high exposure levels (known as the Maximum Tolerated Dose or MTO protocol, see NIP, 1984; OSTP, 1989)* Judgaments of carcinogenic potency based on Information derived from such high levels of exposure may have little relationship to potencies at tower levels of exposure conparable to those found In the environment* Consequently, the basis for potency ranking Is not considered adequately developed for use In a scoring system* However, If procedures for such ranking were found reliable, they would form a reasonable basis for the scoring of the carcinogenic potential of chemicals* Important Information to assist In the Interpretation of animal cancer bloassay data vIs-a-vIs the potential of a chemical to cause cancer In humans can be derived frcsn assessments of Its mutagen let ty/genotoxl c I ty# - 28 - The scoring schame for th?$ parameter Is as follows: PARAMETER SCORE CRITERIA to Direct acting human carcinogen or potential human carcinogen (baseo on animal bloassay data) with e^loence of uirect Interactions with genetic material. Acts as an electrophlle or olrect alkylating agent, proouces DNA aouucts, inuuces cell trans fonnat ion, etc. 8 Indirect acting (epigenetic) human carcinogen or potential human carcinogen (baseo on animal bioassay oata) with evidence that it does not interact with genetic material 6 Carcinogenic in animal bioassay tests at levels of exposure shown to saturate enzymes involved In the metabolism of the compound or at exposure levels shown to cause histopatho logical lesions known to predispose animals to the development of cancers af sites where the lesions are observed (e.g., ATPAse deficient liver foci in rodents). Adequate evidence must be available demonstrating that no Interactions occur with genetic material and that the chemical does not Induce cell transformation. 4 Positive tumorlgenic agent (benign tumours) in humans or animals. Evidence must be available of lack of interactions with genetic material. Includes chemicals that act solely as promoters and those that cause cell transformation in vitro without evidence In other systems 2 Tumorlgenic In only one animal species and negative in other(s) (all studies considered adequate) 0 Not tumorlgenic In an adaquate animal bioassay In at least two species and must not Interact with genetic material Information Sources Information on the carcinogenicity of chemicals would general ly be obtained from original publications and review articles as Identified through lARC Monographs or MEDLINE, TOXLINE databases or National Toxicology Program (NTP) publications* Information may also be available from various summary data sources including Bowman (1982), Fairchlld (1978), Fishbein (1979), Ketchen and Porter (1979), Kirsch-Volders (1983), Sax et al (1981), Soderman (1983), Sontag (1981), and Stich and San (1984). However, It Is difficult to Judge the validity of carcinogenicity data from summary data and original publications should be consulted. MOE SCORING SYSTEM SUMMARY CHART ELEMENT NAME ENDPOINT * UNITS SCORING CRITERIA Environincoiai Tnaipott Percem panuiomaf. measumJor predided Any (ingle nnliuM awiaia* >9S% o( Ik* Mial aaMMM rckiMJ No ooe medium ooautat >9S%, ind only one i rliw toniim >S«ofttclalatHMMM " iKieMed Two medu each coMaio ^S% of Ibe loul amnuiu relesSed Three or more mcUa each com am >,S% ot the UMal ajnoual released or SUbdance is Sotpkoic and it adsortied to panides < lOum ia diameter when released Eaviroammtal Kenistenoe «l/2 (OV*) <10 10lo20loS10 >2J>U>4i) >»OtoLSOOO >4i)io6i> > 15000 >6JD ELEMENT NAME ENDPOINT * UNITS Acute Lethality oralLD^o miJUi >5000 > 200-5000 > 50-500 >5-50 >03-5 <.05 denaalLPso >5000 >500-S000 >«K»0 >5« >0J-5 U000 > 1500-15000 > 130-1500 > 15-150 > 13-15 <.»-5 atj^HtieLCjo >1000 > 100-1000 >l»-IOO >t-10 >aj.i ^OlI ■«/L SMOkiaEBecu, aquatie ^«).«(/L MyCfcTi^ ItakMMaaHli >20 2-<» OJ-la Oj02-.100O 10O-<100O 10- < 100 l.<10 ,500 50-10 >l-10 >0.M >Oj01-0i1 ajooi-ojoi 100 > 10-100 >M0 >OJ-I OjOl-0.1 I00 > 10-100 >M0 >OJ-t Oj014i1 S40(-BCjB) water >100 > 10-100 >1-I0 >0.M Oi>l-1000 >10O-lO0O > 10-100 >1-10 0.1-1 <0J •oil >1000 >IOO-I000 > 10-100 >l-10 OJ-I » water >1000 > 100-1000 > 10-100 >1-10 O.M <0.l •ir > 10000 > 1000-10000 > 100-1000 > 10-100 1-10 IC000 > 1000-10000 > 100-1000 > 10-100 MO 1000 >10O-10OO > 10-100 >1.10 >Q.1-1 <.ai Mammals* mt/kc inhaLNOEL mg/m^ >3000 > 300-3000 > 30-300 >3-30 >0J-3 <.0J TcfaMyiciiy m{/kg/day •olerala. icrau or de««iap- icrau or develop- tenia or dewelop- lerauai >0.1-1. teraia al <1000 >S0-t000 > 10-50 >1-10 toxicity lOKidty ^.^..^wUiy in vivpand in MX teaoUBic or Moiafeaiciii m ■mtafnrir in profca- causes DNA ioduc- causes cUTiOgenie muiagienie m vi«o (no vttrooeUas^r* muiaaeaic; nepiJMe vjtmtmwftoJ^. lyotic eeUt only: itoa or repair, *iih effects, sister duoma- rewtlu jn *iw» aad DeptiMe malls in no direct lotersction lid exchange. vivo assays) in jrjtro ctikao^otic cell assays vitb nuclear material crusslij^iis: no cvidenoe or n.ulation Canaaogenidijr human and no luaoui* in tumours in only ooe causes benign indireGt-actiiig dirca-aaii^ aiumal bioaasay animal species. I amours m nwire bioastays al doses caroBiifem. no interac- carciiio|ea that iMcr- dau at least two species. nej^tiwe resulu ia than oike species. tia«witk|eaeuc acuwiih aad docs KM mtcf^ allien eraynte saturaiioo. material geaetic laateriai ad Willi fcactic actwidl|caeiic or associated with ■Mcrial ■mrriih. pHMDotor oa^orcawesceU inasfDrmalion in vitro only (oetalTvc evidence in vivo) lesions that predispasc to lumottn. No inter- act too with genetic material • NOTE: The Sublethal Effects, Mammals criteria are based on studies of >.90 days duration. If only shorter-term subchronic studies are available, the data are modified as follows, for scoring purposes: Study duration 28-89 days - divide result by 10; Study duration <.28 days - divide result by 100. 13/09/89 * ■; i -J I / J^ Bou ■>■» «.':.,:■;» iiKl HJ f ; d)X)&* -A-1. Appendix A Guidelines for Using Score Qualifiers and Criteria I. General Description of Score Qualiflers Insufficient Information for Scoring (•) The insufficient data (*) tag is used where there are no data for a particular parameter or exposure route available, following a Level II (bibliographic database) search. Any individual oral, inhalational, dermal or aquatic score and tag fields are left blank if no information for them is available after a Level I (factual database and reference text) search. Limited Data (L) The limited data (L) tag is used when the data available is of limited scope. Worst' Case Designation (W) The worst-case tag (W) is used when a score is based on data obtained from a study reporting an unusual endpoint or using a route of administration which would overestimate the hazard. (W)-tagged scores may decrease when additional data becomes available during a subsequent detailed assessment Questionable Data (Q) The questionable-data tag (Q) is used to indicate that the data used does not fiilly match the criteria description, was obtained from situations of questionable relevance to the Ontario environment, or is otherwise questionable due to deficiencies in study or analytical methodology. (Q)*tagged scores may increase qz decrease when additional data becomes avail- able during a subsequent detailed assessment Estimated Data (E) The estimated data tag (E) is used when a value is derived from a model such as a QSAR or fugacity model. In most cases this type of data is acceptable only if "real" data is absent An exception is in scoring persistence (see section II, below). -A-2. Hierarchy of Tags Only a single tag is to be assigned to a score. The order of precedence is: Q « W > E > L. For example, if a score is based on estimated data and also warrants a (W) tag, the tag assigned would be (W). II. Persistence Criteria Types of Data Preferred Biodegradation data best reflecting the conditions in the ambient environment is preferable over data derived from studies using media such as activated sludge. The order of preference is: environmental data (e.g. river die*away, half-life in soils) > some shaker flask studies > QSAR estimates > BOD. When QSAR results in the form *ti/2 > x" are used for scoring, the score is assigned as if ti/2= 2x. If data from the studies mentioned above are available, scoring is not based on other types of studies even if they represent a worst-case. If preferred data is not available, the obtainable data is used and a (Q) tag is assigned. Limited Database When data on persistence are available for one medium only, an (L) tag is assigned. III. Bioaccumulation Criteria Use of Log P in the Absence ofBCF Data When log P values are used in the absence of bioaccumulation factors (BCFs) for scoring bioaccumulation, an (L) tag is assigned. Use of BCFs for Unusual Species When bioaccumulation is scored on the basis of a BCF for an unusual species, e.g. an aquatic organism other than a freshwater fish, a (Q) tag is assigned. -A.3- IV. Acute Lethality Criteria Route of Administration (Terrestrial Species) When acute lethality is being scored, the score is based on intravenous, subcutaneous or intraperitoneal route data only if oral, dermal or inhalational route data are not available. A (W) tag is assigned in these cases, and scores are determined by using the oral LD50 criteria. Aquatic Toxicity Ratings When an overall acute lethality score is based only on an "aquatic toxicity rating" range, an (L) tag is assigned. Saltwater Studies ai^nsiviV Freshwater species studies are preferred over saltwater studies. If an aquatic LC50 score must be based on a saltwater study (Le. no freshwater data exist), a (Q) tag is assigned. Scoring Acute Lethality in the Absence ofLDsc/LCsos otoiwD .1/ When only LDlo ot LClo data are available, the ^ta are scored as if they were for LD/LC50S and a (W) tag is assigned. When only LDioo or LCioo data are available, the data are scored as if they were for LD/lJCs(fi and a (Q) tag is assigned. V. Sublethal Effects Criteria Route of Administration (Mammalian Studies) When sublethal effects are being scored, the score is based on intravenous, subcutaneous and intraperitoneal route data only if oral, dermal or inhalational route data are not available. A (W) tag is assigned in these cases, and scores are determined using the oral exposure criteria. Duration of Study (Mammalian Studies) -^r^ The criteria are based on data from exposures of 90 days or more in duration. If such data is lacking, the results of shorter-term studies are used, tagged as questionable data (Q), and scored based on a modification of the data as described below. The rationale for this is that over a shorter period of time. .A-4- higher concentrations of a toxin may be tolerated by an organism than over a extended period. The order of preference is >.90 days, 28-89 days, <28 days duration. If data from studies of 28 to 89 days exposure duration are used, the data values are divided by 10. If data from studies of less than 28 days exposure duration are used, the data values are divided by 100. Estimating NOAEL when only LOAELs are available (Mammalian Studies) In cases where only LOAELs are available, or in cases where some studies give V LOAEL figures lower than the NOAELs reported in other studies, scores are based on the lowest LOAEL divided by a safety factor of 10, and are tagged (Q). Limited Database When a sublethal effects score is based on only one piece of data or on data for only one species, an (L) tag is assigned. VI. Genotoxicity / Mutagenicity Criteria Absence ofEukaryotic or In Vivo Data If positive prokaryotic in vitro (e.g. Ames salmonella) assays are available, but positive or negative eukaryotic or in vivo data are absent, a score of 4 is assigned, with a (Q) tag. A (Q) tag is also applied when a score of 6 or greater is assigned in the absence of in vivo data. Limited Database When the score is based on only one piece of data or on data for only one species strain, an (L) tag is assigned. VII. Carcinogenicity Criteria Limited Database When the score is based on only one piece of data or on data for only one species strain, an (L) tag is assigned. •B-1- Appendix B Concern Levels for Promotion to the Ontario Effluent Monitoring Priority Pollutants List (EMPPL) The minimum parameter scores leading to promotion of a substance to the EMPPL are as follows: Bioaccumulation.....^...^ ^ 7 Sublethal Toxicity, non-mammals^.^...^..^..^^...^^. 6 Sublethal Toxicity, plants ...^...«....^.^.......^.......^...«« 6 Sublethal Toxicity, mammals «...^...«....... 6 Mutagenicity/Genotoxicity . . ^... 6 Teratogenicity ^. ~ 2 Carcinogenicity............ 2 * - A persistence score equal to or greater than 7 alone does not cause promotion to the EMPPL» but may support promotion based on other parameters.