PUBLIC HEALTH ASSESSMENT
SOLVENT SAVERS
LINCKLAEN, CHENANGO COUNTY, NEW YORK

Figure 1. Solvent Savers Site Location Map

Figure 4. Soil Boring Locations

Figure 5. Monitoring Well Locations

Figure 6. Soil Gas Sampling Locations

Figure 7. Sediment, Surface Water and Air Sampling Locations

Figure 8. Boundaries of Source Areas
ONSITE CONTAMINATION
ORGANIC CHEMICAL CONCENTRATIONS IN SURFACE SOIL
IN MILLIGRAMS PER KILOGRAM (mg/kg)
|
|
||||||
| Organics | Frequency of Detectiona(1) |
Range of Detected Concentrations(1) |
Sample Locationc(1) |
Typical Background Range |
Comparison Value** |
Source*** |
|
|
||||||
| Benzoic Acid | 4/9 | 0.22J-0.65J | ND | 1,470 | EPA RfD | |
|
Butylbenzyl phthalate |
1/9 | 0.43 | ND | 3,220 | EPA RfD | |
|
di-n-Butylphthalate |
2/9 | 0.38J-0.41J | ND | 4,100 | EPA RfD | |
|
Chlorobenzene |
1/9 | 0.003J | ND | 27 | EPA RfD | |
|
Chloroform |
1/9 | 0.005 | ND | 0.2 | EPA CPF | |
|
1,1-Dichloroethane |
1/9 | 0.004J | ND | 33 | EPA RfD | |
|
1,2-Dichloroethane |
1/9 | 0.007J | ND | 0.02 | EPA CPF | |
|
*bis(2-ethylhexyl)phthalate |
3/9 | 0.10J-23D | 50.05 | ND | 2.3 | EPA CPF |
|
*Hexachlorobenzene |
1/9 | 0.41J | 50.05 | ND | 0.004 | EPA CPF |
|
*1,1-Dichloroethene |
1/9 | 0.003J | ND | 0.002 | EPA CPF | |
|
Carcinogenic PAHs, total |
4/9 | 0.49-2.82 | **** | 0.005 | EPA CPF | |
|
Noncarcinogenic PAHs, total |
2/9 | 1.10-2.29 | **** | 67 | EPA CPF | |
|
*Tetrachloroethene |
3/9 | 0.002J-1.30 | 50.05 | ND | 0.06 | EPA CPF |
|
Toluene |
2/9 | 0.041-0.30J | ND | 230 | EPA RfD | |
|
1,1,1-Trichloroethane |
4/9 | 0.002-5.10 | ND | 76 | EPA RfD | |
|
*1,1,2-Trichloroethane |
2/9 | 0.25-1.40 | 50.05 | ND | 0.05 | EPA CPF |
|
*Trichloroethene |
7/9 | 0.002J-33 | 50.05 | ND | 0.2 | EPA CPF |
|
*Aroclor-1242 |
4/50 | 0.74-14,000 | 50.01 | <0.01-0.04b | 0.03b | EPA CPF |
|
*Aroclor-1248 |
20/50 | 0.580J-470J | 50.01 | <0.01-0.04b | 0.03b | EPA CPF |
|
*Aroclor-1254 |
11/50 | 0.35-870 | 50.01 | <0.01-0.04b | 0.03b | EPA CPF |
|
*Aroclor-1260 |
1/50 | 420 | 50.01 | <0.01-0.04b | 0.03b | EPA CPF |
|
|
||||||
J - estimated value
ND - not determined
D - analysis
from diluted sample
aThe number of samples in which the contaminant was detected divided by the total number of samples analyzed.
bTotal PCBs
cRefer to Figure 4, Appendix A; surface soil sample location is listed only for those contaminants selected for further evaluation.
*Contaminant selected for further evaluation.
**Comparison values for organic contaminants based on
ingestion of soil and homegrown vegetables.
***EPA CPF = EPA Cancer Potency Factor
EPA RfD = EPA Reference Dose
****Based on reported background levels for total polycyclic
aromatic hydrocarbons of <1 to 13 mg/kg in soil from relatively rural areas
of the eastern United States (Edwards, 1983).
(1)Data
adapted from: Ebasco Services, Inc. (1990) and Conestoga-Rovers & Associates,
Ltd. (1993).
ONSITE CONTAMINATION
INORGANIC CHEMICAL CONCENTRATIONS IN SURFACE SOIL
IN MILLIGRAMS PER KILOGRAM (mg/kg)
| Metals | Frequency of Detectiona(1) |
Range of Detected Concentrations(1) |
Sample Locationc(1) |
Typical Background Range** |
Comparison Value*** |
Source**** |
|
|
||||||
|
Arsenicb |
5/5 | 7.5 - 12.2 | 10-20 | 15 | EPA RfD | |
|
*Cadmium |
1/9 | 10.6 | 50.06 | <.5-1 | 10 | ATSDR MRL |
|
*Chromium |
9/9 | 18.9 - 289J | 50.06 | 10-40 | 250 | EPA RfD |
|
Cobalt |
9/9 | 8.3 - 19 | <0.3-70 | -- | ||
|
Copper |
9/9 | 16.8 - 106 | <1-25 | 6,500 | EPA RfD | |
|
Lead |
9/9 | 22.7 - 83.4 | 10-300 | -- | ||
|
Mercury |
3/9 | 0.1U - 15 | 0.01-3.4 | 15 | EPA RfD | |
|
Nickel |
9/9 | 24.1 - 429 | <5-20 | 1,000 | EPA RfD | |
|
Zinc |
9/9 | 85.3 - 411 | 50-100 | 10,000 | EPA RfD | |
|
|
||||||
aThe number of samples in which the contaminant was detected divided by the total number of samples analyzed.
bQA/QC problems, 4/9 samples rejected; control limits exceeded on duplicate and spike recovery.
cRefer to Figure ___, Appendix A; surface soil sample location is listed only for those contaminants selected for further evaluation.
U = less than detection limit
J = estimated value
*Contaminant selected for further evaluation.
**References: Adriano (1986); Clarke et al. (1985); Connor et al. (1957); Dragun (1988); Frank et al. (1976); McGovern (1988); Shacklette (1984)
***Comparison values for metals (inorganics) based on ingestion of 200 mg soil by a 10 kg child.
****ATSDR MRL = ATSDR Minimal Risk Level
EPA RfD = EPA Risk Reference Dose
(1)Data adapted from: Ebasco Services, Inc., 1990.
TABLE 2a
ONSITE CONTAMINATION
CHEMICAL CONCENTRATIONS IN SUBSURFACE SOILS
IN MILLIGRAMS PER KILOGRAM (mg/kg)
|
|
|||||
| Organics | Frequency of Detectiona(1) |
Range of Detected Concentrations(1) |
Typical Background Range |
Comparison Value** |
Source*** |
|
|
|||||
|
*Acetone |
7/65 | 0.120BJ-5.700 | NDT | 2 | EPA RfD |
|
*Benzene |
3/65 | 0.0006J-7.40 | NDT | 0.05 | EPA CPF |
|
Benzoic acid |
3/64 | 0.19J-0.38J | NDT | 1,470 | EPA RfD |
|
*Bromoform |
2/65 | 0.0006J-31.0 | NDT | 0.3 | EPA CPF |
|
*2-Butanone |
11/43 | 0.001J,N-72.0J | NDT | 26 | EPA RfD |
|
Butylbenzylphthalate |
1/64 | 0.17J | NDT | 3,200 | EPA RfD |
|
di-n-Butylphthalate |
6/64 | 0.039-2.70 | NDT | 4,100 | EPA RfD |
|
Chlorobenzene |
2/65 | 0.001J,N-0.26J | NDT | 27 | EPA RfD |
|
Chloroform |
21/65 | 0.001J-7.50 | NDT | 0.2 | EPA CPF |
|
1,2-Dichlorobenzene |
4/64 | 0.050J-13 | NDT | 324 | EPA RfD |
|
1,3-Dichlorobenzene |
1/64 | 0.730J | NDT | -- | -- |
|
*1,4-Dichlorobenzene |
1/64 | 2.60J | NDT | 0.4 | EPA CPF |
|
*1,1-Dichloroethane |
1/65 | 0.11 | NDT | 33 | EPA RfD |
|
*1,1-Dichloroethene |
6/65 | 0.1J-0.860 | NDT | 0.002 | EPA CPF |
|
1,2-Dichloroethene, total |
9/65 | 0.0009-6.5 | NDT | 1 | EPA RfD |
|
*bis(2-Ethylhexyl)phthalate |
29/64 | 40J-25.0 | NDT | 2.3 | EPA CPF |
|
Ethylbenzene |
5/65 | 0.001J-26.0 | NDT | 200 | EPA RfD |
|
*Isophorone |
2/64 | 0.073J-0.53J | NDT | 0.03 | EPA CPF |
|
*Methylene chloride |
4/65 | 0.62-0.89 | NDT | 0.07 | EPA CPF |
|
4-Methylphenol |
1/64 | 0.17J | NDT | 19.6 | EPA RfD |
|
di-n-Octylphthalate |
2/64 | 0.024J-0.057J | NDT | 489 | EPA RfD |
|
Benzo(a)anthracene |
1/64 | 0.057J,N | **** | -- | -- |
|
Benzo(b)fluoranthene |
1/64 | 0.088 | **** | -- | -- |
|
Benzo(k)fluoranthene |
1/64 | 0.088 | **** | -- | -- |
|
Chrysene |
1/64 | 0.061J,N | **** | -- | -- |
|
Anthracene |
1/64 | 0.58 | **** | 7,470 | EPA RfD |
|
Dibenzofuran |
1/64 | 0.21 | NDT | -- | -- |
|
Fluoranthene |
1/64 | 0.074J | **** | 746 | EPA RfD |
|
Fluorene |
1/64 | 0.22J | **** | 328 | EPA RfD |
|
2-Methylnaphthalene |
5/64 | 0.079J-520J | NDT | -- | -- |
|
*Naphthalene |
4/64 | 0.056J-53 | NDT | 14.3 | EPA RfD |
|
Phenanthrene |
6/64 | 0.43-0.62 | **** | -- | -- |
|
Pyrene |
2/64 | 0.089J,N-0.14J | **** | 67 | EPA RfD |
|
*Aroclor 1016 |
5/65 | 0.62-38 | <0.01-0.4b | 0.03b | EPA CPF |
|
*Aroclor 1242 |
3/65 | 0.50-41 | <0.01-0.4b | 0.03b | EPA CPF |
|
*Aroclor 1248 |
3/65 | 0.47-22 | <0.01-0.4b | 0.03b | EPA CPF |
|
*Aroclor 1254 |
8/65 | 0.29-54 | <0.01-0.4b | 0.03b | EPA CPF |
|
Pentachlorophenol |
1/64 | 0.37J | NDT | 630 | EPA RfD |
|
Phenol |
1/64 | 0.12J | NDT | 128 | EPA RfD |
|
1,1,2,2-Tetrachloroethane |
3/65 | 0.003J,N-36.0 | NDT | 0.01 | EPA CPF |
|
*Tetrachloroethene |
47/65 | 6J-67 | NDT | 0.06 | EPA CPF |
|
Toluene |
22/65 | 2J-400 | NDT | 230 | EPA RfD |
|
*1,2,4-Trichlorobenzene |
3/64 | 0.22J-1,200 | NDT | 152 | EPA RfD |
|
*1,1,1-Trichloroethane |
51/65 | 0.002J-170J | NDT | 76 | EPA RfD |
|
*1,1,2-Trichloroethane |
9/65 | 0.006-6.5J | NDT | 0.05 | EPA CPF |
|
*Trichloroethene |
55/65 | 0.006-1,000 | NDT | 0.2 | EPA CPF |
|
Total Xylenes |
12/65 | 0.005-440 | NDT | 4,620 | EPA RfD |
TABLE 2a (cont.)
ONSITE CONTAMINATION
CHEMICAL CONCENTRATIONS IN SUBSURFACE SOILS
IN MILLIGRAMS PER KILOGRAM (mg/kg)
|
|
|||||
| Organics | Frequency of Detectiona(1) |
Range of Detected Concentrations(1) |
Typical Background Range |
Comparison Value** |
Source*** |
|
|
|||||
|
Total Tetrachlorodibenzodioxin |
0/17 | ND | NDT | 0.000002 | EPA CPF |
|
*Total Pentachlorodibenzodioxin |
1/17 | 0.0002 | NDT | 0.000004c | EPA CPF |
|
*Total Hexachlorodibenzodioxin |
2/17 | 0.0003-0.001 | NDT | 0.00002c | EPA CPF |
|
*Total Heptachlorodibenzodioxin |
2/15 | 0.001-0.003 | NDT | 0.0002c | EPA CPF |
|
*Total Octachlorodibenzodioxin |
2/11 | 0.005-0.008 | NDT | 0.002c | EPA CPF |
J - estimated value
N - presumed value
aThe number of samples in which the contaminant was detected divided by the total number of samples analyzed.
bTotal PCBs
cThe comparison value was calculated using the US EPA (1989) 2,3,7,8-tetrachlorodibenzodioxin toxicity equivalence factors and assuming
that all of the contaminant is in the 2,3,7,8-substituted form. The factors used are:
2,3,7,8-tetra isomer 1
2,3,7,8-penta isomer 0.5
2,3,7,8-hexa isomer 0.1
2,3,7,8-hepta isomer 0.01
2,3,7,8-octa isomer 0.001
ND = not detected
NDT = not determined
*Contaminant selected for further evaluation.
**Comparison values for organic contaminants based on ingestion of soil and homegrown vegetables.
***EPA CPF = EPA Cancer Potency Factor
EPA
RfD = EPA Reference Dose
****Based on reported background levels for total polycyclic aromatic hydrocarbons of <1 to 13 mg/kg in soil from relatively rural areas of the eastern United States (ATSDR, 1990_; Edwards, 1983)
(1)Data adapted from: Conestoga-Rovers & Associates, Ltd. (1993) and Ebasco Services, Inc. (1990).
ONSITE CONTAMINATION
CHEMICAL CONCENTRATIONS IN SUBSURFACE SOILS
IN MILLIGRAMS PER KILOGRAM (mg/kg)
|
|
|||||
| Inorganics | Frequency of Detectiona(1) |
Range of Detected Concentrations(1) |
Typical Background Range** |
Comparison Value*** |
Source**** |
|
|
|||||
|
Antimony |
12/60 | 2.3 - 9.8 | 0.6-10 | 20 | EPA RfD |
|
*Arsenic |
63/63 | 6.4 - 46.80 | 10-20 | 15 | EPA RfD |
|
Cadmium |
36/64 | 0.69 - 8.70 | <0.5-1 | 10 | ATSDR MRL |
|
Calcium |
64/64 | 416 - 53,900 | 100-400,000 | -- | -- |
|
Cobalt |
64/64 | 8.10 - 19.90 | <0.3-70 | -- | -- |
|
Copper |
53/53 | 17.90 - 74.60 | <1-25 | 6,500 | EPA RfD |
|
Lead |
49/49 | 9.8 - 177 | 10-300 | -- | -- |
|
Magnesium |
64/64 | 3340 - 7600 | 400-15,000 | 250,000 | NYS RfG |
|
Manganese |
64/64 | 254 - 1830 | 500-3,000 | 7,000 | EPA RfD |
|
Nickel |
58/58 | 19.50 - 40.90 | <5-20 | 1,000 | EPA RfD |
|
Selenium |
6/52 | 0.52 - 2.30 | 0.1-4 | 150 | ATSDR MRL |
|
Silver |
2/60 | 1.00 - 1.70 | 0.1-5 | 250 | EPA RfD |
|
Zinc |
64/64 | 58.40 - 331.0 | 50-100 | 10,000 | EPA RfD |
aThe number of samples in which the contaminant was detected divided by the total number of samples analyzed.
*Contaminant selected for further evaluation.
**References: Adriano (1986); Clarke et al. (1985); Connor et al. (1957); Dragun (1988); Frank et al. (1976); McGovern (1988); Shacklette (1984)
***Comparison values for metals (inorganics) based on ingestion of 200 mg soil by a 10 kg child.
****ATSDR MRL = ATSDR Minimal Risk Level
EPA RfD = EPA Risk Reference Dose
NYS
RfG = NYS Reference Guideline
(1)Data adapted from: Ebasco Services, Inc., 1990.
CHEMICAL CONCENTRATION IN GROUNDWATER IN MICROGRAMS
PER LITER (mcg/L)
(see Table 6 for Public Health Assessment Comparison Values)
|
|
||
| Parameter | On-Site Contamination Range (mcg/L) |
Off-Site Contamination Range (mcg/L) |
|
|
||
| Organics | ||
|
*Dichlorodifluoromethane |
0.74-4,467 | 1.7-54.0.5 |
|
*Chloromethane |
1.0U - 25 | 0.84-15U |
|
*Vinyl chloride |
0.66 - 32 | 1.0U-32 |
|
*Trichlorofluoromethane |
0.55 - 240 | 1.0U-24 |
|
*1,1-Dichloroethene |
1.0U - 430 | 1.0U-130 |
|
*Methylene chloride |
1.0U - 15,000 | 1.0U-160 |
|
*trans-1,2-Dichloroethene |
1.0U - 18 | |
|
*1,1-Dichloroethane |
1.0U - 1900 | 1.0U-1,200 |
|
*cis-1,2-Dichloroethene |
1.0U - 27,000 | 1.0U-5,800 |
|
*Chloroform |
1.0U - 2,500 | |
|
*1,1,1-Trichloroethane |
1.0U - 22,000 | 0.51-2,500 |
|
*Carbon tetrachloride |
1.0U - 63 | |
|
*Benzene |
0.93 - 610 | 1.0U-130 |
|
*1,2-Dichloroethane |
1.0U - 43 | 1.5-43.0 |
|
*Trichloroethene |
1.0U - 57,000 | 0.79-13,000 |
|
*Isopropylacetone |
1.0U - 670 | 1.0U-300 |
|
*Toluene |
1.0U - 3500 | 1.0U-1,700 |
|
*1,1,2-Trichloroethane |
1.0U - 170 | 1.0U-21.0 |
|
*Tetrachloroethene |
0.74 - 2100 | |
|
*Chlorobenzene |
0.62 - 17 | |
|
*1,1,1,2-Tetrachloroethane |
0.67 - 5.1 | |
|
*Ethylbenzene |
0.62 - 170 | |
|
*Xylene (m-, p-) |
0.79 - 760 | |
|
*o-Xylene |
0.55 - 540 | 0.51-99 |
|
*1,1,2,2-Tetrachloroethane |
1.0U - 21.3 | |
|
*1,3,5-Trimethylbenzene |
0.57 - 23 | |
|
*1,2,4-Trimethylbenzene |
1.0U - 12 | |
|
*p-Isopropyltoluene |
0.51 - 8.7 | |
|
*1,4-Dichlorobenzene |
0.5 - 19 | |
|
*n-Butylbenzene |
0.7 - 10 | |
|
*1,2-Dichlorobenzene |
1.0U - 150 | |
|
*Naphthalene |
0.50 - 91 | |
|
*2,4-Dichlorophenol |
11J - 37 | |
|
*2-Methylphenol (o-cresol) |
15J - 63 | |
|
*Aroclor 1232 |
0.5U - 72 | |
|
*Aroclor 1242 |
12 | |
|
Inorganics (unfiltered) |
||
|
*Zinc |
29.5 - 31,000 | 21.2-976 |
|
*Lead |
1.0U - 3210 | 1.4J-256 |
|
*Chromium |
5.0U - 234 | 5.0U-254 |
|
*Arsenic |
1.0UJ - 73.1 | 1.0UJ-42.7 |
|
|
||
| Source: Ebasco Services, Inc., 1990 *Contaminant selected for further evaluation. Blank space indicates "not-detected". |
J = estimated value U = less than detection limit |
SOIL GAS SAMPLING RESULTS
SOLVENT
SAVERS SITE
| Sample | Calibrated Compounds | |
|
Trichloroethene |
Tetrachloroethene (conc. ppb) |
|
|
|
||
|
A-5 |
210 | 16 |
|
C-5 |
59 | |
|
E-7 |
9,000 | 26 |
|
E-9 |
450 | |
|
E-11 |
2,900 | 570 |
|
F-2 |
620 | |
|
F-4 |
89 | |
|
F-6 |
14,000 | |
|
F-8 |
10 | |
|
F-12 |
60 | 91 |
|
F-14 |
49 | |
|
G-0 |
92 | |
|
G-7 |
3,600 | 430 |
|
G-11 |
2,400 | 590 |
|
G-13 |
1,900 | 26 |
|
G-14 |
420 | |
| H-6 | 4,800 | |
|
H-8 |
1,400 | 29 |
|
H-10 |
9,500 | 4,700 |
|
H-12 |
320 | 63 |
|
H-14 |
8,600 | 590 |
|
I-7 |
5,800 | 160 |
|
I-9 |
7,600 | 1,100 |
|
I-11 |
60,000 | 11,000 |
|
I-13 |
8,300 | 3,100 |
|
J-6 |
2,000 | 72 |
|
J-8 |
7,200 | 250 |
|
J-10 |
28,000 | 9,000 |
|
J-12 |
2,000 | 180 |
|
J-14 |
9,500 | 640 |
|
K-5 |
140 | |
|
K-7 |
2,600 | 100 |
|
K-9 |
21,000 | 4,400 |
|
K-11 |
17,000 | 2,600 |
|
K-13 |
8,000 | 660 |
|
L-4 |
110 | |
|
L-6 |
140 | 100 |
|
L-8 |
19,000 | 40,000 |
TABLE 4 (continued)
SOIL GAS SAMPLING RESULTS
SOLVENT SAVERS SITE
|
|
||
| Sample | Calibrated Compounds | |
|
Trichloroethene |
Tetrachloroethene (conc. ppb) |
|
|
|
||
|
L-10 |
6,000 | 440 |
|
L-12 |
4,800 | 300 |
|
L-14 |
3,200 | 70 |
|
M-7 |
455 | 30 |
|
M-9 |
13,000 | 470 |
|
M-11 |
16,000 | 2,600 |
|
M-13 |
2,200 | 70 |
|
M-14 |
8,700 | 77 |
|
N-8 |
18,000 | 1,300 |
|
N-9 |
48,000 | 60,000 |
|
N-10 |
16,000 | 4,800 |
|
N-12 |
6,000 | 290 |
|
|
||
|
O-1 |
26 | |
|
O-3 |
23 | |
|
O-5 |
250 | |
|
O-7 |
58 | 21 |
| O-8 | 110 | |
|
O-9 |
60,000 | 20,000 |
|
O-10 |
44,000 | 9,800 |
|
O-11 |
13,000 | 1,000 |
|
O-13 |
2,300 | 85 |
|
P-2 |
10 | |
|
P-4 |
1,700 | 300 |
|
P-6 |
55 | 11 |
|
P-8 |
1,500 | 26 |
|
P-9 |
100 | |
|
P-10 |
6,000 | 170 |
|
Q-3 |
620 | |
|
Q-5 |
88 | 15 |
|
Q-7 |
190 | |
|
Q-11 |
94 | |
|
R-2 |
74 | |
|
R-4 |
20 | |
|
R-6 |
20 | |
|
R-8 |
20 | |
|
T-2 |
170 | |
|
X-1 |
970 | 76 |
|
X-2 |
140 | 90 |
|
|
||
|
Source: Ebasco Services, Inc., 1990. |
Blank space indicates "not detected". |
SUMMARY OF ON-SITE AMBIENT AIR SAMPLES
(ALL RESULTS REPORTED IN MICROGRAMS PER CUBIC METER [MCG/M3])
|
|
|||||
| Chemical | Frequency of Detectiona(1) |
Range of Detected Concentrations(1) |
Typical Background Range** |
Comparison Value*** |
Source**** |
|
|
|||||
| PCB-1242 | 1/12 | 4.62E-04 | 0.0001-0.0042b | 0.0005b | NYS CREG |
|
PCB-1248 |
3/12 | 3.9E-05 - 6.4E-05 | 0.0001-0.0042b | 0.0005b | NYS CREG |
|
Total PCBsc |
4/12 | 2.3E-05 - 2.34E-04 | 0.0001-0.0042 | 0.0005 | NYS CREG |
|
Tetrachloroethene |
7/12 | .22 - 1.48 | 0.2-11.2 | 2 | ATSDR CREG |
|
Toluene |
12/12 | 0.33 - 0.86 | 3-142 | 400 | EPA RfC |
|
1,1,1-Trichloroethane |
12/12 | 1.13 - 9.59 | 0.6-2.3 | 1,000 | EPA RfC |
|
*Trichloroethene |
3/11 | 4.16-10.4 | 0.2-3.2 | 0.6 | ATSDR CREG |
aThe number of samples in which the contaminant was detected divided by the total number of samples analyzed. Total number of samples less than 12 indicates that some samples were rejected for QA/QC reasons.
bTotal PCBs
cTotal PCBs found in each sample was determined for each sample location in each sampling round. The range of these totals was then determined.
E = Exponential
*Contaminant selected for further evaluation.
**References: Brodzinsky and Singh (1982); Singh et al. (1981); NYS DEC (1986)
***Comparison values based on a 70 kilogram adult inhaling 20 cubic meters of air per day.
****ATSDR CREG = ATSDR Cancer Risk Evaluation Guide
EPA RfC = EPA Risk Reference Concentration
NYS
CREG = New York State Inhalation Unit Risk
(1)Data adapted from: Ebasco Services, Inc., 1990.
CHEMICAL CONCENTRATIONS IN MUD CREEK (DOWNSTREAM*)
IN MICROGRAMS PER LITER (mcg/L)
(see Table 6 for Public Health Comparison Values)
|
|
||
| Chemical | Frequency of Detectiona |
Range of Detected Concentrations (mcg/L) |
|
|
||
|
Organics |
||
|
*Methylene chloride |
4/8 | 1.5 - 7.5 |
|
Acetone |
7/8 | 8.2 - 23 |
|
1,1-Dichloroethane |
4/8 | 1.7 - 4.4 |
|
*1,1,1-Trichloroethane |
4/8 | 4.6 - 10.5 |
|
*Trichloroethene |
7/8 | 0.4 - 19 |
|
Benzene |
3/8 | 0.6 - 0.65 |
|
Tetrachloroethene |
3/8 | 0.4 - 0.5 |
|
Toluene |
3/8 | 1.4 - 4.6 |
|
*cis-1,2-Dichloroethene |
6/8 | 11 - 39.5 |
|
m-, p-Xylene |
2/8 | 0.4 |
|
Inorganics |
||
|
*Aluminum |
5/5 | 86 - 5320 |
|
Cobalt |
1/5 | 4.3 |
|
*Iron |
5/5 | 227 - 10700 |
|
*Manganese |
5/5 | 40.9 - 456 |
|
Nickel |
1/5 | 8.8 |
|
Potassium |
5/5 | 873 - 1460 |
|
Vanadium |
2/5 | 3.2 - 8.2 |
|
|
||
Source: Ebasco Services, Inc., 1990.
These data are indicators of contamination and may or may not be sufficiently high to be a significant health concern.
aNumber of samples in which contaminant was detected/total number of samples analyzed.
*One sample was taken upstream of the site; organic chemicals detected were methylene chloride (7.2 UJ) and acetone (7.1 UJ) where
U = undetected
J = estimated value.
*Contaminant selected for further evaluation.
Public Health Assessment Comparison Values for
Contaminants Found in Sources of Drinking Water
[all values in micrograms per liter (mcg/L)]
|
|
||||||
| Chemical | Standards/Guidelines NEW YORK STATE |
U.S. EPA | Comparison Value*** |
Source**** | ||
|
Ground- |
Surface Water |
Drinking Water |
Drinking Water |
|||
|
|
||||||
| Acetone | 50 | -- | 50 | -- | 700 | EPA RfD |
|
Aluminum |
-- | -- | -- | 50-200** | -- | -- |
|
Aroclor, 1232 and 1242 |
0.1 c | 0.01 c | 0.5 c | 0.5 | 0.0045 | ATSDR CREG |
|
Arsenic |
25 | 50 | 50 | 50 | 11 | EPA RfD |
|
Benzene |
0.7 | 0.7 | 5 | 5 | 0.7 | NYS CREG |
|
Butylbenzene, n- |
5 | -- | 5 | -- | -- | -- |
|
Carbon tetrachloride |
5 | 0.4 g | 5 | 5 | 0.27 | ATSDR CREG |
|
Chlorobenzene |
5 | 20 | 5 | 100 | 140 | EPA RfD |
|
Chloroform |
7 | 7 | 100 d | 100 d | 6 | EPA CPF |
|
Chloromethane |
5 | -- | 5 | -- | 3 | EPA LTHA |
|
Chromium |
50 | 50 | 100 | 100 | 100 | EPA LTHA |
|
Cobalt |
-- | -- | -- | -- | -- | -- |
|
Dichlorobenzene, 1,2- |
4.7 e | -- | 5 | 600p; 10ps | 600 | EPA LTHA |
|
Dichlorobenzene, 1,4- |
4.7 e | 30 | 5 | 75; 5 ps | 1.5 | EPA CPF |
|
Dichlorodifluoromethane |
5 | -- | 5 | -- | 1,000 | EPA LTHA |
|
Dichloroethane, 1,1- |
5 | 5 g | 5 | -- | 700 | EPA RfD |
| Dichloroethane, 1,2- | 5 | 0.8 | 5 | 5 | 0.38 | ATSDR CREG |
| Dichloroethene, cis-1,2- | 5 | -- | 5 | 70 | 70 | EPA LTHA |
| Dichloroethene, trans-1,2- | 5 | 5 g | 5 | 100 | 100 | EPA LTHA |
| Dichloroethene, 1,1- | 5 | 0.07g | 5 | 7 | 0.058 | ATSDR CREG |
| Dichlorophenol, 2,4- | 0.3 g | 0.3 | 5 | -- | 20 | EPA LTHA |
| Ethylbenzene | 5 | 5 g | 5 | 700; 30ps | 700 | EPA LTHA |
| Iron | 300 | 300 | 300 | 300s | -- | -- |
| Isopropylacetone | 50 | -- | 50 | -- | -- | -- |
| Isopropyltoluene, p- | 5 | -- | 5 | -- | -- | -- |
| Lead | 25 | 50 | 50 | 15* | -- | -- |
| Manganese | 300 | 300 | 300 | 50s | 175 | EPA RfD |
| Methylene chloride | 5 | 5 g | 5 | 5 p | 4.7 | ATSDR CREG |
| Methylphenol, 2- | 1 | 1 | 50 | -- | 360 | EPA RfD |
| Naphthalene | 10 g | 10 | 50 | -- | 20 | EPA LTHA |
| Nickel | -- | -- | -- | 100 | 100 | EPA LTHA |
| Potassium | -- | -- | -- | -- | -- | -- |
| Tetrachloroethane, 1,1,1,2- | 5 | -- | 5 | -- | 1.3 | ATS DR CREG |
| Tetrachloroethane, 1,1,2,2- | 5 | 0.2 g | 5 | -- | 0.18 | ATSDR CREG |
| Tetrachloroethene | 5 | 0.7 g | 5 | 5 | 0.7 | NYS CREG |
| Toluene | 5 | 5 g | 5 | 1,000; 40ps | 1,000 | EPA LTHA |
| Trichloroethane, 1,1,1- | 5 | 5 g | 5 | 200 | 200 | EPA LTHA |
| Trichloroethane, 1,1,2- | 5 | 0.6 | 5 | 5 | 0.61 | ATSDR CREG |
| Trichloroethene | 5 | 3 g | 5 | 5 | 3 | NYS CREG |
| Trichlorofluoromethane | 5 | 5 g | 5 | -- | 2,200 | EPA RfD |
| Trimethylbenzene, 1,2,4- | 5 | 5 g | 5 | -- | -- | -- |
| Trimethylbenzene, 1,3,5- | 5 | 5 g | 5 | -- | -- | -- |
| Vanadium | -- | -- | -- | -- | 20 | EPA LTHA |
| Vinyl chloride | 2 | 0.3 g | 2 | 2 | 0.02 | EPA CPF |
| Xylene, o- | 5 n | 5 g,n | 5 n | 10,000i; 20ps | 10,000 | EPA LTHA |
| Xylenes (total) | 5 n | 5 g,n | 5 n | 10,000i; 20ps | 10,000 | EPA LTHA |
| Zinc | 300 | 300 | 5,000 | 5,000 s | 2,100 | EPA LTHA |
|
|
||||||
c = total PCBs
d = Drinking water standard for total trihalomethanes
which are produced as a result of disinfection with chlorine. This standard
is inappropriate for evaluating environmental contamination not associated with
disinfection practices.
e = applies to total of 1,2- and 1,4- isomers
g = guidance value
i = total xylenes
n = applies to each isomer separately unless isomers
are analytically indistinguishable
ND = not detected
p = proposed maximum contaminant level (MCL)
ps = proposed secondary MCL
s = secondary MCL
*The maximum contaminant level goal (MCLG) for lead is
zero and there is an action level of 15 mcg/L at the tap.
**US EPA Federal Register, Vol. 50, Nov. 13, 1985; secondary
level
***Comparison values based on a 70 kilogram adult drinking
2 liters of water per day.
****ATSDR CREG = ATSDR Cancer Risk Evaluation Guide
EPA LTHA = EPA Drinking Water Lifetime Health Advisory
EPA CPF = EPA Cancer Potency Factor
EPA RfD = EPA Reference Dose
NYS CREG
= NYS Cancer Risk Evaluation Guide
PROCEDURE FOR EVALUATING POTENTIAL HEALTH RISKS
FOR CONTAMINANTS OF CONCERN
To evaluate the potential health risks from contaminants of concern associated with the Solvent Savers site, the New York State Department of Health assessed the risks for cancer and noncancer health effects.
Increased cancer risks were estimated by using site-specific information on exposure levels for the contaminant of concern and interpreting them using cancer potency estimates derived for that contaminant by the US EPA or, in some cases, by the NYS DOH. The following qualitative ranking of cancer risk estimates, developed by the NYS DOH, was then used to rank the risk from very low to very high. For example, if the qualitative descriptor was "low", then the excess lifetime cancer risk from that exposure is in the range of greater than one per million to less than one per ten thousand. Other qualitative descriptors are listed below:
Excess Lifetime Cancer Risk
| Risk Ratio | Qualitative Descriptor |
| equal to or less than one per million | very low |
| greater than one per million to less than one per ten thousand | low |
| one per ten thousand to less than one per thousand | moderate |
| one per thousand to less than one per ten | high |
| equal to or greater than one per ten | very high |
An estimated increased excess lifetime cancer risk is not a specific estimate of expected cancers. Rather, it is a plausible upper bound estimate of the probability that a person may develop cancer sometime in his or her lifetime following exposure to that contaminant (i.e., there is only about a 5 percent chance that the risk of a response is greater than the estimated value).
There is insufficient knowledge of cancer mechanisms to decide if there exists a level of exposure to a cancer-causing agent below which there is no risk of getting cancer, namely, a threshold level. Therefore, every exposure, no matter how low, to a cancer-causing compound is assumed to be associated with some increased risk. As the dose of a carcinogen decreases, the chance of developing cancer decreases, but each exposure is accompanied by some increased risk.
There is no general consensus within the scientific or regulatory communities on what level of estimated excess cancer risk is acceptable. Some have recommended the use of the relatively conservative excess lifetime cancer risk level of one in one million because of the uncertainties in our scientific knowledge about the mechanism of cancer. Others feel that risks that are lower or higher may be acceptable, depending on scientific, economic and social factors. An increased lifetime cancer risk of one in one million or less is generally considered an insignificant increase in cancer risk.
For noncarcinogenic health risks, the contaminant intake was estimated using exposure assumptions for the site conditions. This dose was then compared to a risk reference dose (estimated daily intake of a chemical that is likely to be without an appreciable risk of health effects) developed by the US EPA, ATSDR and/or NYS DOH. The resulting ratio was then compared to the following qualitative scale of health risk:
Qualitative Descriptions for
Noncarcinogenic Health Risks
| Ratio of Estimated Contaminant Intake to Risk Reference Dose |
Qualitative Descriptor |
| equal to or less than the risk reference dose |
minimal |
| greater than one to five times the risk reference dose |
low |
| greater than five to ten times the risk reference dose |
moderate |
| greater than ten times the risk reference dose |
high |
Noncarcinogenic effects unlike carcinogenic effects are believed to have a threshold, that is, a dose below which adverse effects will not occur. As a result, the current practice is to identify, usually from animal toxicology experiments, a no-observed-effect-level (NOEL). This is the experimental exposure level in animals at which no adverse toxic effect is observed. The NOEL is then divided by an uncertainty factor to yield the risk reference dose. The uncertainty factor is a number which reflects the degree of uncertainty that exists when experimental animal data are extrapolated to the general human population. The magnitude of the uncertainty factor takes into consideration various factors such as sensitive subpopulations (for example, children or the elderly), extrapolation from animals to humans, and the incompleteness of available data. Thus, the risk reference dose is not expected to cause health effects because it is selected to be much lower than dosages that do not cause adverse health effects in laboratory animals.
The measure used to describe the potential for noncancer health
effects to occur in an individual is expressed as a ratio of
estimated contaminant intake to the risk reference dose. If
exposure to the contaminant exceeds the risk reference dose, there
may be concern for potential noncancer health effects because the
margijn of protection is less than that afforded by the reference
dose. As a rule, the greater the ratio of the estimated
contaminant intake to the risk reference dose, the greater the
level of concern. A ratio equal to or less than one is generally
considered an insignificant (minimal) increase in risk.
SUMMARY OF PUBLIC COMMENTS
AND RESPONSES
SUMMARY OF PUBLIC COMMENTS AND RESPONSES
SOLVENT SAVERS, LINCKLAEN, CHENANGO COUNTY, NEW YORK
This responsiveness summary was prepared to address the public comments on the Solvent Savers draft Public Health Assessment. The public was invited to comment on the draft Public Health Assessment during the public comment period which ran from April 16, 1993 to May 21, 1993 and responses were received by the New York State Department of Health. Some comments were consolidated or grouped together to incorporate similar concerns raised by more than one person. If you have any questions about this responsiveness summary, contact the Health Liaison Program at the toll-free number 1-800-458-1158, extension 402.
COMMENT #1
It should be noted that not all of the residences are situated upgradient of the contaminants. A nearby residential well is located downgradient of drum disposal site #1. In addition, since it is acknowledged that sampling at the site was incomplete, the health assessment may need to be reconsidered in light of new information that may be developed.
COMMENT #2
We have strong concerns about the risk of later contamination to local wells, especially the nearby house and well situated at the same and lower level than the dump site. We also feel that water sampling is not complete and should continue.
RESPONSE #1 and #2
This well is not downgradient of the site; it is north of the site and the direction of groundwater flow in the site area is from west to east. Therefore, groundwater contamination is not expected to reach this well. The NYS DOH has sampled this and other private wells around the site since 1984 and no contamination has been found in these wells. Once the site is remediated, migration of contaminated groundwater from the site will be controlled, eliminating the potential for contamination of nearby residential wells. Until the site is remediated, the NYS DOH recommends that monitoring of the private wells continue. NYS DOH has included this recommendation in this Public Health Assessment.
COMMENT #3
We have strong concerns about the possible contamination of Mud Creek later, after there has been more time for migration of the toxic plume and that proper sampling has not been performed at this time.
COMMENT #4
Based on the geology, topography and hydrology of the site, it is clear that contaminants are moving toward Mud Creek. Considering the highly rural character of the region and the lack of residences in the proximity of the site, it is clear that Mud Creek contamination is an important factor in assessing impacts.
RESPONSE #3 and #4
The data show that surface water in Mud Creek is being affected by site contamination. The levels of contaminants in the creek immediately next to the site are elevated; however, the level of contamination drops rapidly moving down stream, away from the site. The toxicological implications of exposure to these levels have been evaluated in this Public Health Assessment and indicated that exposures would present a minimal health risk. The impact(s) to Mud Creek will be addressed as part of site remediation.
COMMENT #5
Area citizens are very concerned about the final levels of contamination left on site after the cleanup is final.
RESPONSE #5
The final clean-up levels proposed in the feasibility study (FS) and the record of decision (ROD) were consistent with the clean-up levels that are used in a residential setting. This setting has the lowest clean-up levels compared to other possible settings. Therefore, the remediation should provide adequate protection for any future use of the site.
COMMENT #6
We object to the use of "typical background" ranges for substances such as lead. Inorganic comparisons should be based on local, ambient concentrations, not the range of values found within a region or state.
RESPONSE #6
US EPA considers the subsurface sample from soil boring (SB-1) to be the background soil sample for the site. Local subsurface soil samples from areas off-site were not collected during past investigations of the site. Although local background soil sample data is preferred, in many cases the literature data are adequate for comparison purposes for inorganics (i.e., metals). For this public health assessment, typical regional background ranges from the literature for the metals detected in on-site soils are presented in Tables 1b and 2b. Given the site status and adequacy of the remediation, additional information on local background would not have an impact.
COMMENT #7
With all the analysis conducted, we are curious why cyanides were not reported. With the variety of contaminants that were dumped at the site, it is likely that cyanides were also disposed at the site.
COMMENT #8
Why is it that mercury determinations were not conducted in the subsurface soils? Since this substance was measured at concentrations of up to 15 mg/kg in surface soils, it should also be assessed in subsurface soils. Select soil metal concentrations increased with depth at the site including arsenic and lead. There is a general inconsistency with the analytical protocols for soils and sediments in that select metals were analyzed in the surface samples or deeper sediments and not always in both.
RESPONSE #7 and #8
All samples collected during the remedial investigation (RI) were analyzed for cyanides and mercury. Some results were rejected because the data did not pass the quality assurance/quality control (QA/QC) review. The laboratory QA/QC procedure determines if the samples were analyzed properly. Cyanide and mercury were not detected in the samples whose analysis passed the QA/QC reviews. Not detected means that cyanide was not detected in the sample at levels above the detection limit. Table 2B has been revised to present all cyanide results, including values reported by the laboratory to be not detected.
COMMENT #9
Future PCB analysis should be congener-specific in that select congeners are more soluble and volatile and the toxicities of congeners also vary.
RESPONSE #9
Congener-specific analysis is not needed at this site. Congener-specific analysis is generally used to determine slight variations in the make-up of a PCB (polychlorinated biphenyl) mixture; this information can be used to identify a specific source of PCB contamination among many sources. Even though the congeners differ in toxicity, they are regulated as mixtures, partly because long-term toxicological studies have not been done on individual congeners. Given these limitations in toxicity and our knowledge of this site, the PCB Aroclor analysis for the RI at the Solvent Savers site is sufficient.
COMMENT #10
We take exception to the use of the United States Fish and Wildlife Service (USF&WS) data on water, sediment and fish from Mud Creek. Many of the substances found at the Solvent Savers site are relatively insoluble. It is not known whether the species selected were exposed to contaminants for any length of time since it is not known whether the fish occupied the site where they were sampled for any extended period of time. It is our opinion that little can be deduced relative to the distribution and concentration of Solvent Savers site contaminants because the study design was flawed. If the potential risk to the public that come in contact with or use Mud Creek is to be measured based on the results of the USF&WS study, it is our opinion that such conclusions are fundamentally flawed.
RESPONSE #10
The USF&WS study was designed to evaluate the effect of site contamination on fish and wildlife resources at and near the site. The most direct way to evaluate if site contamination has accumulated in fish is to sample the fish and analyze the fish tissue. While there are many factors which may influence the results of such a study, the results are adequate to evaluate exposure from fish ingestion that may contain site contaminants.
COMMENT #11
We feel that there should be more cooperation between all agencies on the design and implementation of studies on the site so that if any agency must use information from others for their work they know how studies were done and can use the information effectively.
RESPONSE #11
We agree.
COMMENT #12
If biological sampling is to be used to determine the extent of bioaccumulation, benthic organisms should be selected. In this way it will be definitive regarding exposures. The insect larvae should have been used for chemical analysis rather than the selected fish since it is not possible to determine the mobility of the fish sampled.
RESPONSE #12
The purpose of taking sampling determines what media should be sampled. Benthic organisms (e.g., mayfly larvae) do supply several advantages over fish if the purpose of the sampling is to determine ecological impacts or tract contamination. This is because they are relatively immobile, have a 1-year life span (so age is not a compounding factor) and are in close contact with the sediments. However, sampling and analyzing of fish is the most direct way of assessing human exposures to site contaminants from ingesting fish caught during recreational fishing.
COMMENT #13
Page 18 - paragraph 4: "How low is a low increased cancer risk"?
RESPONSE #13
The risks for cancer and noncancer health effects were assessed to evaluate potential health risks from exposure to contaminants of concern associated with the Solvent Savers site. Increased cancer risks were estimated by using site-specific information on exposure levels for the contaminant of concern and interpreting them using cancer potency estimates derived for that contaminant by the US EPA or, in some cases, by the NYS DOH. The following qualitative ranking of cancer risk estimates, developed by the NYS DOH, was then used to rank the risk from very low to very high. For example, if the qualitative descriptor was "low", then the excess lifetime cancer risk from that exposure fell in the range of greater than one per million to less than one per ten thousand. Other qualitative descriptors are listed below:
| Risk Ratio | Qualitative Descriptor |
| equal to or less than one per million | very low |
| greater than one per million to less than one per ten thousand |
low |
| one per ten thousand to less than one per thousand |
moderate |
| one per thousand to less than one per ten | high |
| equal to or greater than one per ten | very high |
An increased excess lifetime cancer risk is not an estimate of expected cancers. Rather, it is an estimate of the probability that a person may develop cancer sometime in his or her lifetime following exposure to that contaminant.
COMMENT #14
Does the cleanup process address the potential of wind blown contamination of products or byproducts of cleanup to surrounding residences -- within what area or potential uphill downwind sites?
RESPONSE #14
The health and safety of the community near the Solvent Savers site will be considered during site remediation. Community health and safety will be addressed as part of the health and safety plan developed for the site to ensure that remediation activities do not result in releases of site contaminants at levels of public health concern.
New information and clarification and corrections on specific data were received from the consulting firm for Bristol-Myers Squibb Co. and General Electric. Revisions were made to the text; responses to the consultant's comments on the Toxicological Implications section of the draft public health assessment follow.
COMMENT #15
The presentation of the noncarcinogenic health effects in humans exposed to PCBs is inaccurate. While a wide range of effects, including dermatological, systemic, neurologic, reproductive, and immunologic effects have been observed in laboratory animals exposed to high doses of PCBs, in studies of the most highly exposed human (i.e., worker) populations, PCBs have not been shown to be a significant risk factor for any of these effects. Since PCB levels have been shown to be 10 to 10,000 times greater in workers than in the general population (NIOSH, 1977), and because there are no definitive noncarcinogenic effects associated with these levels, the human health hazard associated with the very low PCB levels typical of environmental exposures is most certainly de minimis.
RESPONSE #15
Animal experiments have clearly shown that PCBs can damage many organs and organ systems, including the skin, liver, blood and the nervous, reproductive and immune systems (ATSDR, 1991i). Human effects reported after occupational exposures to PCBs include skin, eye and respiratory tract irritation and less frequently, effects on the liver and the nervous and digestive systems (ATSDR, 1991i). The conclusion that PCBs caused these effects is only tentative because the workers were also exposed to other chemicals, including the contaminants of PCBs. The consistent reports of skin toxicity among PCB-workers and the fact that PCBs cause skin toxicity in animals suggest that PCBs have caused skin toxicity in workers and may pose a risk to humans who are exposed to lower levels over long periods of time.
Mean PCB serum levels in the general population are generally around 5 to 7 parts per billion (ppb) whereas reported mean serum levels for occupational studies range from 3 to 394 ppb (ATSDR, 1991). Mean PCB serum levels in occupational populations are about 80 times higher than those in the general population.
The health effects seen in humans occupationally exposed to PCBs are similar to those induced in animals exposed to PCBs. In addition, the limited epidemiological data on the mortality of PCB workers are inadequate to conclude that there are no noncarcinogenic effects associated with occupational exposure to PCBs. Collectively, these data indicate that it is premature to conclude that the noncarcinogenic human health hazards associated with the very low PCB levels typical of environmental exposures are de minimis. Moreover, the PCB groundwater levels found at the Solvent Savers site are substantially higher than levels typically found in the environment. However, the discussion of the human health effects of PCBs on page 17 was modified to improve clarity and avoid misinterpretation.
COMMENT #16
Epidemiology studies of environmentally exposed women and their offspring (Fein et al., 1984; Jacobson et al., 1985; Rogan et al., 1986a; Gladen et al., 1988; Jacobson et al., 1990a,b; Gladen and Rogan, 1991) have not shown a causal relationship between PCB exposure and human reproductive or development effects. In addition to not providing causal evidence that PCBs are human reproductive or developmental toxicant, these studies have serious scientific limitations, including their inability to differentiate between PCB exposures and exposures to other suspect chemicals.
RESPONSE #16
Animal experiments have clearly shown that PCBs are developmental and neurological toxicants in rodents and rhesus monkeys (ATSDR, 1991; Golub et al., 1991). They have also shown that prenatal (before birth) PCB exposure produces lower birthweights and neurological effects in monkeys. Epidemiology studies of environmentally exposed women and their children show a relationship between increased exposure to PCBs and reproductive/developmental effects, specifically lower birthweight and neurobehavioral effects (ATSDR, 1991i; Gladen and Rogan, 1991; Rogan and Gladen, 1991, 1992). These studies, like many epidemiological studies, examined the correlations between PCB exposure and effects and cannot prove that PCBs were the sole factor responsible for the observed effects. This is a limitation of all epidemiological studies. The fact that two independent, well-designed and well-executed epidemiological studies showed that low-level PCB exposure was associated with neurobehavioral effects and the fact that PCBs caused similar effects in animals raise significant concerns about the human reproductive/developmental risks of long-term, low-level exposure to PCBs.
COMMENT #17
It is stated in the fourth paragraph on page 17 that, based on animal studies, chronic exposures may pose "high" incremental cancer risk for individuals exposed to PCBs. This statement may be misinterpreted by readers because it has not been clearly communicated that conservative methods, procedures, and analyses have been used that tend to produce upper-bound overestimates of potential human health risks.
RESPONSE #17
The methods and procedures that were used to estimate increased cancer risks are consistent with those used by scientists at federal agencies and many scientific advisory groups. Much scientific data are required to calculate the estimates and there are many areas where necessary data are not available or are limited. Scientists have developed models, procedures and assumptions to compensate for this lack of data. Often, there is more that one model, procedure or assumption that is consistent with the available data and no clear-cut scientific basis to choose one model, for example, over another model. When faced with such uncertainty, the choice of model, procedure or assumption should be consistent with the available data but also consistent with a protective public health policy (err on the side of public health). When such choices are made, the derived estimates are often called upper bound estimates of risk because the true risk (if we knew it, which we don't) is more likely to be below the risk estimate than above the risk estimate. This conservation is necessary because of the uncertainties in the available data and the serious public health consequences that could result if risks were underestimated. A discussion of this issue has been added to the document as Appendix C.
COMMENT #18
On page 17, in paragraph 4, the characterization of the potential noncarcinogenic effects of benzene, methylene chloride, cis-1,2-dichloroethene, chloroform, PCBs, tetrachloroethene, 1,1,1-trichloroethane and trichloroethene is misleading. ATSDR states that noncarcinogenic effects associated with these compounds are observed at exposure levels several orders of magnitude higher than those potentially associated with the site. Environmental exposures rarely approach in magnitude the high exposures that are applied in toxicity tests or that are derived from epidemiology studies where true effects are observed. In addition, most noncarcinogenic dose-response relationships include a threshold for effects. Thus, if the noncarcinogenic effects of these compounds are observed at exposures that are orders of magnitude greater than those potentially presented by the Solvent Savers site, then the noncarcinogenic risks from exposure to these compounds at the Solvent Savers site should not be characterized as "high" (as is done in the draft public health assessment).
RESPONSE #18
The use of the term "several orders of magnitude" is misleading. PCBs cause noncarcinogenic effects in animals at exposure levels only about two to three times greater (not several orders of magnitude greater) than potential exposures from on-site groundwater. Trichloroethene, 1,1,1-trichloroethane, cis-1,2-dichloroethene, methylene chloride and chloroform cause noncarcinogenic effects at exposure levels about one to two orders of magnitude greater, and benzene and tetrachloroethene about two to three orders of magnitude greater than potential exposure from on-site groundwater. The text of the Public Health Assessment has been revised accordingly.
To estimate the risks of noncarcinogenic effects from potential exposures, the intake for each contaminants (expressed in terms of dose and estimated by using exposure assumptions for conditions at the Solvent Savers site) was compared to a risk reference dose. A risk reference dose is an estimate (with an uncertainty spanning perhaps an order of magnitude or greater) of a daily exposure level for the human population that is likely to be without any appreciable risk of adverse health effects. If exposure to a contaminant exceeds the risk reference dose, there may be concern for potential noncarcinogenic effects because the margin of protection is less than that afforded by the reference dose. As a rule, the greater the decrease in the margin of protection, the greater the level of concern. In general, when the estimated intake of a contaminant is greater than about 10 times its reference dose, the risk is characterized as high (a discussion of procedures for evaluating potential health risks has been added to the document as Appendix C). The estimated potential intake for each of the Solvent Saver site contaminants that could pose a high risk of noncarcinogenic health effects is greater than ten times its respective reference dose. For example, estimated potential exposure to PCBs in drinking water is about 400 times greater than its reference dose and only about 2 times less than a dose that caused adverse health effects in animals. Estimated potential exposures to the chlorinated solvents of concern range from about 10 times greater for 1,1,1-trichloroethene to about 400 times greater for trichloroethene.