The criteria for PCBs in drinking water supplies from various jurisdictions are shown in Table 8. However, drinking water criteria for PCBs were not set in this document for two reasons. The primary reason behind this inaction was the fact that PCBs are under review for possible addition to the Guidelines for Canadian Drinking Water Quality, a document which is published and periodically updated by Health and Welfare Canada (1989). It was also noted that raw drinking water supplies are not a significant source of PCB body burden in humans. The results in Table 9 lend support to this argument.
The contribution of various sources to the PCB body burden of an adult male was estimated, based on recommended concentrations and objectives for the contaminants in food, air, and in ambient waters for the protection of aquatic life and its consumers (Table 9). The results show that food and air together comprise most of the tolerable daily intake (TDI) of 60 µg PCBs (for an average adult weighing 60 kg) recommended by Health and Welfare Canada (Grant, 1983). A raw drinking water supply, in which the maximum allowable PCB concentration may be determined by the most sensitive water use (e.g., aquatic life), is an insignificant source of PCBs. Assuming that other factors (i.e., intake from food and air) remain the same, the advisory concentration of 0.5 µg total PCBs/L by U.S. EPA (1988) may be acceptable for drinking water (i.e., using this concentration, the maximum allowable body burden for PCBs was calculated to be 59.9 µg/person-d, which is slightly less than the tolerable daily intake).
The results (Table 9) also suggest that fish is the main source of PCB body burden in humans. The section of the population whose diet contains significantly higher amounts of fish and shellfish (above the average daily consumption shown in Table 9) will be especially vulnerable.
|
TABLE 8 PCB CRITERIA FOR DRINKING WATER SUPPLIES |
||||
|
Criteria Statements |
Criteria Values |
Jurisdiction |
Date |
Reference |
|
(µg/L) |
||||
|
Desirable objective; |
undetectable
|
Saskatchewan |
1985 |
Chan, 1985 |
|
Recommended maximum concentration |
3.0 |
Ontario |
1983 |
OME, 1983 |
|
Recommended standard |
0.1 |
Quebec |
1984 |
Trépanier, 1984 |
|
Recommended maximum concentration |
3.0 |
Nova Scotia |
1985 |
Environment Canada, 1986 |
|
1-d EPA Suggested No Adverse Response
Level (SNARL) for child; |
125 12.5 |
EPA |
1981 |
US EPA, 1981 |
|
1-d NAS-SNARL for an adult;
|
350 |
NAS |
1981 |
US EPA, 1981 |
|
Advisory drinking water criteria:
|
0.5 |
EPA |
1988 |
US EPA, 1988 |
|
TABLE 9 Theoretical maximum allowable daily body burden of PCBs from various sources |
||||
|
FOOD |
||||
|
Category |
Daily intake# |
Average fat content (%) |
Recommended concentration (µg PCBs/g)a |
PCBs intake |
|
meat |
194 |
15 |
0.2 (fat basis) |
5.8 |
|
eggs |
44 |
15 |
0.1 (whole less shell) |
0.44 |
|
poultry |
27 |
15 |
0.5 (fat basis) |
2.0 |
|
fish |
20 |
- |
2.0 (edible portion) |
40.0 |
|
dairy products ## |
420 |
5 |
0.2 (fat basis) |
4.2 |
|
Total (Food) |
52.4 |
|||
|
AIR |
||||
|
Category |
Daily intake |
Recommended concentration (µg/m3) b |
PCBs intake |
|
|
Adult engaged in light physical activity |
15 |
0.45 (0.5-h average) |
6.75 |
|
|
DRINKING WATER |
||||
|
Category |
Daily intake |
Recommended concentration (µg/L) c |
PCBs intake |
|
|
Adult |
1.5 |
0.001 |
0.0015 |
|
a Health and Welfare guidelines (Grant, 1983);
b Ontario ambient air quality criteria (OME, 1984a);
c CCREM (1987) guideline for aquatic life;
# Nutrition Canada (1975);
## ~ 5.5 % cheese (22-39 year old adults; Nutrition Canada, 1975)