Phytotoxicology survey report : UCAR Carbon Canada Incorporated, Welland, 1992 & 1993

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PHYTOTOXICOLOGY SURVEY REPORT:
UCAR CARBON CANADA INCORPORATED
WELLANa 1992 AND 1993

JULY 1994

Ministry of

® Ontario aSr

ISBN 0-7778-2930-7

PHYTOTOXICOLOGY SURVEY REPORT:

UCAR CARBON CANADA INCORPORATED

WELLAND

1992 AND 1993

JULY 1994

©

Cette publication technique
n'est disponible qu'en anglais.

Copyright: Queen's Printer for Ontario, 1994

This publication may be reproduced for non-commercial purposes

with appropriate attribution.

FIBS 3193

PHYTOTOXICOLOGY SURVEY REPORT^

UCAR CARBON CANADA INCORPORATED

WELLAND

1992 & 1993

Report prepared by:

William I. Gizyn

Standards Development Branch

Phytotoxicology Section

Ontario Ministry of Environment and Energy

Report No: SDB-(X)2-35 12-94

Abstract

Phytotoxicology Survey Report:

UCAR Cïirbon Canada Incorporated

Welland - 1992 & 1993

Report No: SDB-002-35 12-94

In 1992 and 1993 surveys involving collection of soil and foliage samples, with subsequent
analysis for polynuclear aromatic hydrocarbons (PAH) were conducted in the vicinity of UCAR
Carbon Canada Incorporated in Welland. This company manufactures carbon and graphite elec-
trodes. The soil samples collected near the plant were clearly contaminated by PAHs emitted by
UCAR. Evidence of this source-related contamination was restricted to the immediate vicinity of
the plant. Tree foliage contamination indicated current, ongoing deposition.

Table of Contents

1 Introduction 1

2 Survey Design 1

3 Sampling and Analytical Procedures 3

4 Results 4

5 Discussion 10

5.1 PAHs in Soil 10

5.2 PAHs in Foliage : 11

5.3 UCAR-Area Soil PAHs in Perspective 12

6 Conclusions 13

7 Appendix 14

SDB-002-35 12-94

1 Introduction

Union Carbide Canada Limited operates a carbon and graphite electrode manufacturing
facility in Welland. This UCAR Carbon Canada Incorporated plant is located on an 'L' -shaped
property in the southern part of the city. It consists of several buildings and other structures, dis-
tributed over approximately 40 hectares. In this report, this facility will be referred to as UCAR.

The primary raw materials for the production of carbon and graphite electrodes are anthracite
coal or petroleum coke and coal tar pitch. The process involves mixing the raw materials, forming
or extruding the mix, and baking at high temperatures. Graphite electrodes are produced by
impregnating the carbon electrodes with more pitch and baking again.

Due to the nature of the raw materials and the high temperatures involved, the production of
carbon and graphite electrodes is associated with emissions to the atmosphere of a variety of organic
compounds.

One group of compounds that could be emitted are polynuclear aromatic hydrocarbons,
commonly known by the acronym, PAH. Chemically these compounds consist of carbon and
hydrogen atoms in two or more benzene rings. The properties of individual PAH compounds are
determined by the number and orientation of these rings. Coal tar pitch consists primarily of PAHs.

In April 1992, the MOEE Welland District Office requested that the Phytotoxicology Section
conduct a survey that would evaluate the impact of PAH emissions by UCAR on the residential
neighbourhoods near the plant.

2 Survey Design

The Phytotoxicology Section utilizes soil and vegetation as indicators of airborne contam-
inants. A typical survey design consists of one or more transect lines originating at the suspected
source of the contaminant. At regular intervals long these lines, homogeneous receptors are located
and sampled.

This approach was not amenable to the UCAR survey. The UCAR property had numerous
potential sources of PAH compounds. Residential properties were located in the north through east
quadrant. The other quadrants contained industrial properties and transportation corridors, or were
vacant or agricultural land.

The residential neighbourhoods that were the focus of concern with respect to PAH deposition,
offered the greatest potential for locating suitable homogeneous receptors. The receptors would be
soil from undisturbed yards and tree foliage from a common species. A typical sampling site
consisted of a rear yard of a single-family house with a lawn grass cover and a silver maple tree.
The house would be at least 25 years old and discussions with the occupant would attempt to
eliminate properties were new sod had recently been laid.

SDB-002-35 12-94 1

A total of 15 properties were selected for sampling of the two receptors. Thirteen of these
were in the UCAR vicinity and two control properties were located about 3.5 kilometres to the
north. All but one of the properties met the criteria described above. The exception was Site 13,
which was located on the grounds of a hospital instead of being a rear yard of a residential property.

The distribution of the target properties covered the residential quadrant in a relatively uniform
manner. Figure 1 shows the location of the 13 UCAR-area sites in relation to the UCAR buildings.
Table 1 lists the geographic coordinates of the sampling sites according to the 6° Universal
Transverse Mercator (UTM) projection.

Figure 1 : Location of Sampling Sites - UCAR Carbon Canada Incorporated Survey

»io

■iiSft*»;«*««K ■»'.iî»2î'W»«j>'*wi.î^^»!fc«vi«'^œiw«»i!aw*^^

OhJTARIO ROAD

*-

*E

'&■

HUMBERSTONE ROAD

located approximatsly 2.5 km north of map

N

i

8^

1000 METRES

SDB-002-35 12-94

Table 1 : Sampling Site UTM Coordinates

Site

Zone

Easting

Northing

1

17

0643010

4759040

2

17

0643240

4758640

3

17

0643320

4759180

4

17

0643710

4758720

5

17

0643780

4759120

6

17

0643570

4758270

7

17

0643880

4758020

8

17

0644540

4759210

9

17

0644190

4759830

10

17

0643460

4759710

11

17

0643260

4759460

12

17

0642300

4759330

13

17

0642630

4759850

14

17

0642400

4762300

15

17

0642300

4762200

3 Sampling and Analytical Procedures

Prior to sampling, all equipment which would contact a sample was washed with a laboratory
detergent solution, rinsed with distilled water, and then sequentially rinsed with acetone and hexane.
Amber glass jars, which would contain the samples, had aluminum foil lining on the lid and had
been solvent-washed by the analytical laboratory.

A soil sample consisted of approximately 10 cores, two centimetres in diameter and five
centimetres deep. The cores were obtained with an Oakfield™ chromed steel, soil corer from
throughout the lawn area, avoiding apparently disturbed areas. The cores were placed into a stainless
steel bowl and homogenized with a stainless steel spoon. The soil was then transferred to the glass
sample jar.

Tree foliage samples were obtained by cutting a branch from the side of the silver maple tree
facing UCAR and removing approximately 20 leaves. These leaves were cut into fragments,
approximately five square centimetres in size, using stainless steel scissors, mixed in a stainless
steel bowl and transferred to the 250 ml glass jar.

All samples were labelled and a sketch of the property prepared showing the location of the
sample tree and the soil sampling area. This would facilitate re-sampling in the future.

Soil and foliage samples were delivered to the MOEE Laboratory Services Branch (LSB)
with a request to determine the concentrations of a variety of PAH compounds. Details of the
methods can be obtained from the laboratory by citing method PSAPAH-E3350A for soil samples
and PVAPAH-E3352A for vegetation samples. These methods provide PAH concentrations in soil
on a dry weight basis; and in vegetation on a fresh weight basis.

SDB-002-35 12-94

TheLSB routinely analyses soil and vegetation samples for 16 PAH compounds. The rationale
for selecting these 16 compounds is related to the adoption of the US-EPA analytical methods by
LSB.

The Appendix contains information about these 16 compounds in the form of structural and
molecular formulas, molecular weights and boiling points. The order of presentation is based on
the molecular weight and structural complexity. High molecular weight PAHs have high boiling
points and are more likely to persist in soil and vegetation. Eight of these compounds, those on the
right side of the appendix page, are considered possible or probable human carcinogens (Menzie
et al, 1992)'.

In 1992, the sampling was conducted on September 15. A workload backlog at the laboratory
prevented analysis and the samples were held in a refrigerator (i.e. unfrozen) for about ten months.
There was concern that PAH compounds present in the 1992 samples may have degraded in storage.
Consequently, the survey was repeated on July 23, 1993. Analyses of ail samples were completed
by October, 1993.

4 Results

The concentrations of individual PAH compounds in each soil and foliage sample are listed
in Tables 2 through 5. Eighty-eight percent of the foliar concentrations of PAHs were below the
analytical detection limits, indicated by the code '<W'. Virtually all remaining foliar concentrations
were qualified with the code '<T', indicating a measurable trace quantity. Only one datum was not
qualified. Soil concentrations were generally of sufficient magnitude to be reported without qual-
ifiers.

Prior to attempting an interpretation of these data, some simplification of the information was
required. The most basic simplification would have been to total the concentrations of the 16 PAHs
in each sample. However, because many of the data were qualified, the concept of 'Net Total' was
developed. A 'Net Total' concentration was calculated by summing the individual PAH concen-
trations as reported and then subtracting the sum of the individual detection limits (<W values). A
'Net Total' concentration can be described as the tqtal of individual PAH concentrations above the
detection limits.

This approach treated each sample equally and provided a single datum representing a PAH
concentration above a certain base level. This base level was 380 nanograms per gram, which was
the sum of the <W detection limits of the 16 PAH compounds. The 'Net Total' concentrations are
presented in the respective Tables 2 through 5, and are plotted as histograms in Figures 2 and 3.

1 Menzie, C.A., B.B. Potocki and J. Santodonato, Exposure to Carcinogenic PAHs in the Envi-
ronment, Envi. Sci. Technol. Vol. 26. No. 7, 1992

SDB-002-35 12-94

Table 2:

PAH Concentrations in Surface Soil (ng/g d.w.)
UCAR Survey- 1992

Site 1

Site 2

Site 3

Site 4

Site 5

Site 6

Site .7

Site 8

Naphthalene

20

<W

20 <W

20

<W

20

<W

29

<T

26

<T

29

<T

20 <W

Acenaphthylene

20

<W

45 <T

20

<W

20

<W

20

<W

20

<W

20

<W

20 <W

Acenaphthene

21

<T

216

29

<T

21

<T

24

<T

38

<T

20

<W

20 <W

Fluorene

20

<W

106 <T

20

<W

20

<W

20

<W

22

<T

20

<w

20 <W

Phenanthrene

202

1164

186

<T

236

208

286

60

<T

39 <T

Anthracene

28

<T

230

26

<T

43

<T

30

<T

47

<T

20

<w

20 <W

Fluoranthene

415

3136

387

456

492

608

120

<T

88 <T

Pyrene

358

2489

326

377

410

540

105

<T

80 <T

Benzo(a)anthracene

249

1334

224

302

325

421

82

<T

65 <T

Chrysene

278

1262

234

311

393

427

76

<T

59 <T

Benzo(k)fluoranthene

270

1225

241

336

319

421

84

<T

20 <W

Benzo(b)fluoranthene

324

1207

286

394

413

530

84

<T

61 <T

Benzo(a)pyrene

331

1417

295

445

396

592

103

<T

83 <T

lndeno( 1 ,2,3-cd)pyrene

427

1623

293

<T

506

420

640

45

<T

46 <T

Benzo(g,h,i)perylene

351

<T

1319

263

<T

418

342

<T

544

40

<W

40 <W

Dibenz(a,h)anthracene

136

<T

561

112

<T

163

<T

40

<W

253

<T

40

<W

40 <W

1 'NET TOTAL' PAH

3070

16974

2582

3688

3501

5035

568

341

Site 9

Site 10

Site 11

Site 12

Site 13

Site 14

Site 15

Naphthalene

34

<T

30

<T

23

<T

40

<T

59

<T

28

<T

33

<T

Acenaphthylene

20

<W

20

<W

20

<W

20

<W

87

<T

20

<W

20

<W

Acenaphthene

20

<W

20

<W

20

<',V

20

<W

20

<W

20

<W

20

<W

Fluorene

20

<W

20

<W

20

<w

20

<W

20

<W

20

<w

20

<W

Phenanthrene

25

<T

210

141

<T

176

<T

260

22

<T

39

<T

Anthracene

20

<W

37

<T

20

<w

21

<T

49

<T

20

<W

20

<W

Fluoranthene

47

<T

454

224

363

999

44

<T

70

<T

Pyrene

47

<T

345

180

<T

304

987

42

<T

65

<T

Benzo(a)anthracene

44

<T

186

<T

112

<T

185

<T

601

44

<T

55

<T

Chrysene

41

<T

163

<T

121

<T

200

<T

499

39

<T

51

<T

Benzo(k)fluoranthene

46

<T

173

<T

115

<T

180

<T

622

47

<T

60

<T

Benzo(b)fluoranthene

47

<T

185

<T

140

<T

205

695

40

<T

50

<T

Benzo(a)pyrene

69

<T

207

133

<T

204

719

62

<T

70

<T

lncleno( 1 ,2,3-cd)pyrene

40

<W

249

<T

112

<T

215

<T

767

40

<W

40

<W

Benzo(g,h,i)perylene

40

<W

210

<T

134

<T

196

<T

626

40

<W

40

<W

Dibenz(a,h)anthracene

40

<W

40

<W

40

<W

40

<W

208

<T

40

<W

40

<W

■NET TOTAL' PAH

220

2169

1175

2009

6838

188

313

SDB-002-35 12-94

Table 3:

PAH Concentrations in Surface Soil (ng/g d.w.)
UCAR Survey -1993

Site 1

Site 2

Site 3

Site 4

Site 5

Site 6

Site 7

Site 8

Naphthalene

20

<W

44 <T

20 <W

20

<W

20

<W

20

<W

32

<T

27

<T

Acenaphthylene

20

<W

20 <W

20 <W

20

<W

20

<W

20

<W

20

<W

20

<W

Acenaphthene

20

<w

150 <T

20 <W

20

<w

26

<T

20

<w

20

<W

20

<W

Fluorene

20

<w

64 <T

20 <W

20

<w

20

<W

20

<w

20

<W

20

<w

Phenanthrene

115

<T

820

252

90

<T

182

<T

83

<T

58

<T

37

<T

Anthracene

20

<W

206

222

20

<W

28

<T

20

<w

20

<W

20

<w

Fluoranthene

311

2920

607

417

429

160

<T

120

<T

80

<T

Pyrene

311

2413

506

370

354

141

<T

106

<T

73

<T

Benzo(a)anthracene

240

1906

394

366

275

135

<T

105

<T

72

<T

Chrysene

259

1796

398

369

288

141

<T

96

<T

67

<T

Benzo(k)fluoranthene

324

2424

460

437

325

163

<T

111

<T

81

<T

Benzo(b)fluoranthene

375

2414

593

549

470

191

<T

144

<T

87

<T

Benzo(a)pyrene

409

2950

646

631

479

193

<T

169

<T

112

<T

lndeno(1 .2,3-cd)pyrene

490

3161

834

833

661

202

177

<T

105

<T

Benzo(g,h,i)perylene

400

<T

2593

649

666

498

156

<T

170

<T

126

<T

Dibenz(a,h)anthracene

141

<T

540

253 <T

275

<T

193

<T

51

<T

40

<W

40

<W

'NET TOTAL' PAH

3095

24041

5514

4723

3888

1336

1028

607

Site 9

Site 10

Site 11

Site 12

Site 13

Site 14

Site 15

Naphthalene

20

<W

20

<W

20

<W

139

<T

35

<T

20

<W

20

<W

Acenaphthylene

20

<W

20

<W

20

<W

20

<W

20

<W

20

<W

20

<W

Acenaphthene

20

<W

20

<W

20

<',V

20

<W

20

<W

20

<w

20

<W

Fluorene

20

<W

20

<W

20

<w

20

<W

20

<w

20

<w

20

<W

Phenanthrene

28

<T

73

<T

99

<T

253

173

<T

20

<w

32

<T

Anthracene

20

<W

20

<W

20

<W

34

<T

24

<T

21

<T

20

<W

Fluoranthene

56

<T

191

<T

235

477

316

20

<w

64

<T

Pyrene

56

<T

165

<T

201

385

261

26

<T

59

<T

Ben20(a)anthracene

61

<T

131

<T

164

<T

275

194

<T

37

<T

58

<T

Chrysene

60

<T

127

<T

169

<T

273

191

<T

32

<T

57

<T

Benzo(k)fluoranthene

66

<T

163

<T

183

<T

289

205

39

<T

66

<T

Benzo(b)fluoranthene

75

<T

177

<T

220

364

255

37

<T

72

<T

Benzo(a)pyrene

95

<T

215

234

364

271

60

<T

89

<T

lndeno(1 ,2.3-cd)pyrene

40

<W

227

<T

259

<T

409

309

<T

40

<W

70

<T

Ben20(g,h,i)perylene

106

<T

216

<T

223

<T

322

<T

265

<T

74

<T

102

<T

Dibenz(a.h)anthracene

40

<W

98

<T

112

<T

143

<T

119

<T

40

<W

40

<W

'NET TOTAL' PAH

403

1503

1819

3407

2298

146

429

SDB-002-35 12-94

Table 4:

PAH Concentrations in
UCAR

Silver Maple Foliage (ng/g
Survey - 1 992

f.W

)

Site

1

Site

2

Site 3

Site

4

Site

5

Site

6

Site

7

Site 8

Naphthalene

20

<w

20

<W

NA

20

<W

20

<W

20

<W

20

<W

20 <W

Acenaphthylene

20

<w

20

<W

NA

20

<W

20

<W

20

<W

20

<w

20 <W

Acenaphthene

20

<w

20

<W

NA

20

<W

20

<W

20

<W

20

<w

20 <W

Fluorene

20

<w

20

<W

NA

20

<W

20

<W

20

<W

20

<w

20 <W

Phenanthrene

20

<w

20

<W

NA

20

<W

20

<W

20

<W

20

<w

20 <W

Anthracene

20

<w

20

<W

NA

20

<W

20

<W

20

<W

20

<w

20 <W

Ruoranthene

29

<T

58

<T

NA

20

<W

20

<W

27

<T

20

<w

27 <T

Pyrene

32

<T

75

<T

NA

20

<w

26

<T

33

<T

23

<T

23 <T

Benzo(a)anthracene

40

<T

77

<T

NA

20

<w

20

<W

20

<W

20

<W

20 <W

Chrysene

53

<T

198

<T

NA

41

<T

45

<T

54

<T

37

<T

42 <T

Benzo(k)f1uoranthene

20

<W

86

<T

NA

20

<W

20

<W

20

<W

20

<W

20 <W

Benzo(b)fluoranthene

20

<W

123

<T

NA

20

<W

20

<W

20

<W

20

<W

20 <W

Benzo(a)pyrene

20

<W

100

<T

NA

20

<w

20

<W

20

<W

20

<W

20 <W

lndeno(1 ,2,3-cd)pyrene

40

<W

40

<W

NA

40

<w

40

<w

40

<W

40

<W

40 <W

Benzo(g,h,i)perylene

40

<W

40

<W

NA

40

<w

40

<w

40

<W

40

<W

40 <W

Dibenz(a,h)anthracene

40

<W

40

<W

NA

40

<w

40

<w

40

<W

40

<W

40 <W

•NET TOTAL' PAH

74

577

NA

21

31

54

20

32

Site 9

Site 10

Site 11

Site 12

Site 13

Site 14

Site 15

Naphthalene

20

<W

20

<W

36

<T

20

<W

20

<W

20

<W

20 <W

Acenaphthylene

20

<W

20

<W

20

<W

20

<W

20

<W

20

<W

20 <W

Acenaphthene

20

<w

20

<W

20

<VV

20

<W

20

<w

20

<w

20 <W

Ruorene

20

<w

20

<W

20

<W

20

<W

20

<w

76

<T

20 <W

Phenanthrene

20

<w

20

<W

20

<W

20

<W

20

<w

20

<w

20 <W

Anthracene

20

<w

20

<W

20

<W

20

<W

20

<w

20

<w

20 <W

Ruoranthene

20

<w

22

<T

33

<T

26

<T

20

<w

20

<w

20 <W

Pyrene

20

<w

25

<T

52

<T

28

<T

21

<T

20

<w

20 <W

Benzo(a)anthracene

20

<w

20

<W

20

<W

20

<W

20

<W

20

<w

20 <W

Chrysene

42

<w

64

<T

126

<T

53

<T

41

<T

20

<w

20 <W

Benzo(k)fluoranthene

20

<w

20

<W

47

<T

20

<W

20

<W

20

<w

20 <W

Benzo(b)fluoranthene

20

<w

20

<W

61

<T

20

<W

20

<W

20

<w

20 <W

Benzo(a)pyrene

20

<w

20

<W

20

<W

20

<W

20

<v

20

<w

20 <W

lndeno(1 ,2,3-cd)pyrene

40

<w

40

<W

40

<W

j <W

40

<w

40

<w

40 <W

Benzo(g,h,i)perylene

40

<w

40

<W

40

<W

40

<W

40

<w

40

<w

40 <W

Dibenz(a,h)anthracene

40

<w

40

<W

40

<W

40

<W

40

<w

40

<w

40 <W

NET TOTAL' PAH

22

51

235

47

22

56

0

SDB-002-35 12-94

Table 5:

PAH Concentrations in Silver Maple Foliage (ng/g f.w.)
UCAR Survey -1993

Site 1

Site 2

Site 3

Site 4

Site 5

Site 6

Site 7

Site 8

Naphthalene

57

<T

47

<T

64

<T

20

<w

20

<W

37

<T

22

<T

20

<W

Acenaphthylene

27

<T

20

<W

20

<W

20

<w

20

<W

20

<W

20

<W

20

<W

Acenaphthene

20

<W

20

<W

20

<W

20

<w

20

<w

20

<W

20

<W

20

<w

Fluorene

20

<W

20

<W

20

<W

20

<w

20

<w

20

<W

24

<T

20

<w

Phenanthrene

20

<W

20

<W

20

<W

20

<w

20

<w

20

<W

20

<W

20

<w

Anthracene

20

<W

20

<w

20

<W

20

<w

20

<w

20

<w

20

<W

20

<w

Fluoranthene

20

<W

20

<w

20

<W

20

<w

20

<w

20

<w

20

<W

22

<T

Pyrene

20

<W

20

<w

20

<W

20

<w

20

<w

20

<w

20

<W

20

<w

Benzo(a)anthracene

20

<W

85

<T

20

<W

20

<w

20

<w

20

<w

20

<W

20

<w

Chrysene

20

<W

206

20

<W

20

<w

42

<T

20

<w

20

<W

20

<w

Benzo(k)fluoranthene

20

<W

85

<T

20

<W

20

<w

20

<w

48

<T

20

<W

20

<w

Benzo(b)fluoranthene

20

<W

98

<T

20

<W

20

<w

20

<w

56

<T

20

<W

20

<w

Benzo(a)pyrene

20

<W

20

<W

20

<W

20

<w

20

<w

20

<W

20

<W

20

<w

lndeno(1 ,2,3-cd)pyrene

40

<W

40

<W

40

<w

40

<w

40

<w

40

<W

40

<W

40

<w

Benzo(g,h,i)perylene

40

<w

40

<W

40

<w

40

<w

40

<w

40

<W

40

<W

40

<w

Dibenz(a,h)anthracene

40

<w

40

<W

40

<w

40

<w

40

<w

40

<W

40

<W

40

<w

NET TOTAL- PAH

44

421

44

0

22

81

6

2

Site 9

Site 10

Site 11

Site 12

Site 13

Site 14

Site 15

Naphthalene

21

<T

20

<W

20

<W

23

<T

20

<w

20

<w

20 <W

Acenaphthylene

20

<W

20

<W

20

<W

20

<W

20

<w

20

<w

20 <W

Acenaphthene

20

<W

20

<w

20

<>.V

20

<W

20

<w

20

<w

20 <W

Fluorene

20

<w

20

<w

20

<W

20

<W

20

<w

20

<w

20 <W

Phenanthrene

20

<w

20

<w

20

<W

20

<W

20

<w

20

<w

20 <W

Anthracene

20

<w

20

<w

20

<W

20

<W

20

<w

20

<w

20 <W

Fluoranthene

20

<w

24

<T

20

<W

20

<W

20

<w

20

<w

20 <W

Pyrene

20

<w

20

<W

20

<W

20

<W

20

<w

20

<w

20 <W

Benzo(a)anthracene

20

<w

74

<T

20

<W

20

<W

20

<w

20

<w

20 <W

Chrysene

20

<w

57

<T

67

<T

20

<W

20

<w

20

<w

20 <W

Benzo(k)fluoranthene

20

<w

20

<W

20

<W

20

<w

20

<w

20

<w

20 <W

Benzo(b)fluoranthene

20

<w

20

<W

20

<W

20

<w

20

<w

20

<w

20 <W

Benzo(a)pyrene

20

<w

20

<W

20

<W

20

<w

20

<w

20

<w

20 <W

lndeno(1 ,2,3-cd)pyrene

40

<w

40

<W

40

<W

40

<w

40

<w

40

<w

40 <W

Benzo(g.h.i)perylene

40

<w

40

<W

40

<W

40

<w

40

<w

40

<w

40 <W

Dibenz(a.h)anthracene

40

<w

40

<W

40

<w

40

<w

40

<w

40

<w

40 <W

1 'NET TOTAL' PAH

1

95

47

3

0

0

0

SDB-002-35 12-94

Figure 2:

f;

<

S I

o I

o °
o (S

X

<

Q.

Ij

O

25

20

15

10

■NET TOTAL' PAH CONCENTRATIONS IN SURFACE (0-5 cm) LAWN SOIL
UCAR SURVEYS - 1992 & 1993

rW^ -wj— g

2 3 4 5 6 7 8 9 10 11 12 13 14 15

SITE NUMBER

1992

1993

Figure 3;

<

ce

o
o

X

<

o

600

500

400

300

200 -

100

•NET TOTAL' PAH CONCENTRATIONS IN SILVER MAPLE FOLIAGE
UCAR SURVEYS - 1992 & 1993

m^

2 3 4 5

6 7 8 9

SITE NUMBER

10 11 12 13 14 15

1992

1993

SDB-(X)2-35 12-94

5 Discussion

Polynuclear aromatic liydrocarbons are widely distributed in the environment. Natural sources
include forest and prairie fires and volcanic eruptions. Any process that involves high temperature
pyrolysis of naturally occurring organic material, such as coal, is a potential source of PAHs. Coke
production is one such source. PAHs are also present in a variety of products derived from petroleum
hydrocarbons, such as asphalt. Consequently, it is quite common to encounter PAHs in the envi-
ronment where there are no near-by point sources.
5.1 PAHs in Soil

The sampling sites in this survey contain a wide range of soil PAH concentrations. However,
these sites can be assigned to three groups according to the relative magnitudes of the 'Net Total'
concentrations.

Figure 2 reveals that soil from Site 2 contains about 20,000 nanograms per gram (ng/g) of
these PAHs. This is by far the highest concentration encountered. A group of nine sites
(1,3,4,5,6,10,11,12,13) have concentrations in the 1,000 to 5,000 ng/g range. The third group
contains five sites (7,8,9,14,15) with soil concentrations below 1,000 ng/g.

The sites within each group are located at different relative distances from the UCAR
property. Site 2 is located within 200 metres of some of the UCAR process buildings. The second
group includes sites within the residential neighbourhoods to the north and east of UCAR. The
third group consists of sites that are furthest from UCAR, and includes the two control sites. This
pattern implicates UCAR as the source of the PAHs in the soil.

The data also suggest that the UCAR influence is limited to the immediate vicinity of the
plant. PAHs in soil at Sites 8 and 9, the most distant of the UCAR-area sites at about 1 .5 kilometres
from the nearest UCAR building, are very similar to the control Sites 14 and 15.

With this limited data set, it is not possible to delineate the contamination zone with certainty.
The concentrations encountered in the soil at a given site would be influenced by the intensity of
the deposition and the length of time that the soil was exposed to such deposition. A property that
had new soil added or indigenous soil tilled would likely have lower concentrations than a
neighbouring property which was not amended.

The data also contain some discrepancies. Samples collected from the same site in the two
successive years usually have similar concentrations. This suggests that the effect of the 1992
sample analysis delay was minimal. However, on occasion the concentrations of PAHs in the
paired samples differed. The 1992 Sites 6 and 13 "Net Total" soil concentrations were about

SDB-002-35 12-94 10

threefold higher than the respective 1993 concentrations. The Site 6 discrepancy can be ascribed
to sampling in different parts of the yard. The location of the 1992 sample was found to be disturbed
during the 1993 visit and a sample had to be collected from a different part of the yard.

The 1992 Site 13 sample had relatively high concentrations of PAHs when compared to
sites closer to, or at similar distances from, UCAR. There may be a local source responsible for a
heterogeneous distribution of PAHs in soil at this site. One possibility is runoff from an asphalt-
paved parking lot which is very close to and uphill from the sampling site.

Frequently when there are complicating factors such as alternate sources of an identical
contaminant, or variable receptor exposure period, it becomes very difficult to ascribe a con-
taminant to a source. However, if the source is sufficiently large, these compUcations are relegated
to the status of minor anomalies. This is the case for PAH emissions by UCAR. The emissions
and deposition of PAHs are of significant magnitude and duration that they have contaminated
the soil on various residential properties in the vicinity of the source.

5.2 PAHs in Foliage

The PAH in silver maple foliage data are dominated by one observation; namely that the
foliage at Site 2 contains a quantity of PAH compounds substantially higher than at other sites.
The "Net Total" concentrations of PAHs were 577 and 421 ng/g, on a fresh weight basis, in 1992
and 1993, respectively. Virtually all other samples had concentrations below 100 ng/g, with the
exception of the 1992 sample from Site 11. Since the 1993 sample from the same tree had a much
lower concentration, the 1992 datum is considered an anomaly.

The quantification of PAHs in tree foliage is not a routine procedure for the Phytotoxicology
Section. The experience is limited to collection of foliage samples near three tire fires in 1990.
PAHs were not detected in such samples at two small fires, near Kingsville and Gormley. They
were detected on spruce needles collected near the Hagersville tire fire. Unfortunately, a con-
centration comparison is not possible because the Hagersville samples were processed in a different
manner. The needles were washed with a solvent and the solvent analyzed.

The presence of PAHs in the silver maple foliage samples from Site 2 indicates an active
deposition process. Assuming that the uptake of PAHs from soil is minimal, these compounds
could only have accumulated between the time the foliage emerged in the spring and the time of
sampling. This is contrary to the situation in soil where PAHs would accumulate as long as
microbial degradation or photo-oxidation of the PAH compounds was slower than the rate of
deposition. Therefore, foliar PAH concentrations should reflect concentrations in the ambient air
during the current growing season, whereas soil PAH concentrations should reflect longer-term
deposition.

SDB-002-35 12-94 11

5.3 UCAR-Area Soil PAHs in Perspective

To this point, this report has identified PAH soil contamination, ascribed it to the UCAR
operation, and delineated, in broad terms, its intensity and geographic extent. It remains to place
this contamination into perspective by comparing the UCAR concentrations to those encountered
elsewhere. Table 6 compares the 1993 concentrations detected at UCAR Sites 2 and 3 to con-
centrations encountered during two 1990 background soil surveys, one in Toronto and the other
in Windsor.

The Toronto survey was conducted by SENES Consultants Ltd.^ and involved samphng 30
municipal parks in the urban core of the City of Toronto. The Windsor survey was conducted by
the MOEE Phytotoxicology Section^ and sampled 12 parks throughout the City of Windsor. In
both cases the soil samples were collected from the top five centimetres in the same manner as in
the UCAR survey. The Toronto and Windsor concentrations represent individual park sites with
the highest frequencies of maximum concentrations, and therefore represent 'worst-case' soil
contamination by PAHs from a variety of background sources in an urban environment.

Table 6:

Soil PAH Concentrations (ng/g d.w.)
UCAR Sites 2 and 3 vs. Toronto and Windsor Parks

Welland

UCAR Site 2

(1993)

Welland

UCAR Site 3

(1993)

Toronto

par1<

(1990)

Windsor

park

(1990)

Naphthalene

44 <T

20 <W

50 <

20 <W

Acenaphthylene

20 <W

20 <W

50 <

20 <W

Acenaphthene

150 <T

20 <W

80

20 <W

Fluorene

64 <T

20 <W

130

20 <W

Phenanthrene

820

252

730

236

Anthracene

206

222

200

58 <T

Fluoranthene

2920

607

900

754

Pyrene

2413

506

930

583

Benzo(a)anthracene

1906

394

na

369

Chrysene

1796

398

680

253

Benzo(k)fluoranthene

2424

460

na

417

Benzo(b)fluoranthene

2414

593

na

577

Ben2o(a)pyrene

2950

646

590

453

lndeno(1 ,2,3-cd)pyrene

3161

834

490

789

Benzo(g,h,i)perylene

2593

649

560

506

Dibenz(a,h)anthracene .

540

253 <T

na

108 <T

2 SENES Consultants Ltd. Soil Sampling Program for Determination of Background Levels of
PAH'S in Toronto Soils, Report to the Corporation of the City of Toronto Housing Department,
February, 1991

3 Gizyn, W.I., Windsor Air Quality Study - Soil and Garden Produce Survey Results, Ministry of
Environment and Energy, 1994

SDB-002-35 12-94

12

This comparison reveals that the soil PAH concentrations encountered at UCAR Site 2
clearly exceed the concentrations encountered in the most heavily contaminated Toronto and
Windsor park soil. The concentrations at UCAR Site 3 are very similar to the 'worst-case' sites
in Toronto and Windsor. This is a clear indication that the soil PAH concentrations near UCAR
in Welland are source-oriented and they are higher than normally encountered in an urban
enviroimient.

6 Conclusions

Emissions of PAH compounds by the UCAR Carbon Canada hicorporated plant in Welland
have resulted in the contamination of soil on neighbouring residential properties. The soil PAH
concentrations at survey sites close to UCAR were similar or higher than the highest concentrations
encountered in urban parks during background surveys. The geographic extent of the UCAR
influence on soil appears to be limited to within approximately one kilometre of the plant. The
contamination of tree foliage by PAH compounds indicates current deposition.

SDB-002-35 12-94 13

7 Appendix

Molecular Structures, Formulae and Weights and Boiling Points of 16 Polynuclear Aromatic Hydrocarbons

00

Naphthalene
CioHe

MW = 128.18
BP = 218

00?

Benzo(a)anthracene |

C18H12

MW = 228.30

BP = 435

cS

Acenaphthylene
C12H8

MW= 152.20
BP = 270

(»

Acenaphthene
C12H10

MW= 154.20
BP = 278

OdO

Ruorene
C13H10

MW= 166.23
BP = 295

o9

Phenanthrene
C14H10

MW = 178.24
BP = 339

000

Anthracene
C14H10

MW = 178.24
BP = 340

cS9

Fluoranthene
CisHio

MW = 202.26
BP = 375

Pyrene
CieHio

MW = 202.26
BP = 393

06^

Chrysene
C18H12

MW = 228.30
BP = 448

Benzo(k)fluoranthene

C20H12

MW = 252.32

BP = 481

oôo

Benzo(b)fluoranthene

C20H12

MW = 252.32

BP = 481

0629

Benzo(a) pyrene

C20H12

MW = 252.32

BP = 495

a®)

lndeno(1 ,2,3-cd)pyrene |

C22H12

MW = 276.34

BP = 536

Benzo (g , h, i) perylene

C22H12

MW = 276.34

BP = 525

Dibenz(a,h)anthracene

C22H14

MW = 278.36

BP = 524

SDB-002-35 12-94

14