Appendix 4: Summary of Data used in Risk Quotient (Q) Analyses of PFOS
| EEVa (µg.L-1) | CTVb (µg.L-1) | AFc | ENEV (µg.L-1) | Q (EEV/ ENEV |
|---|---|---|---|---|
| 0.121 | 49.1 | 100 | 0.491 | 0.25 |
| EEVd (µg.g-1 liver) | CTVe (µg.g-1 liver) | AFf | -1 liver)ENEV(µg.g | Q (EEV/ ENEV) |
|---|---|---|---|---|
| 0.015 - 1.78 | 60.9 | 100 | 0.609 | 0.002 – 2.92 |
| EEVg (µg.mL-1 serum) | CTV (µg.mL-1 serum) | AFf | ENEV (µg.mL-1 serum) | Q (EEV/ ENEV |
|---|---|---|---|---|
| 0.372 – 2.20 | 87.3 | 100 | 0.87 | 0.43 – 2.54 |
| EEVh (µg.g-1 liver) | CTVi (µg.g-1 liver) | AFf | ENEV (µg.g-1 liver) | Q (EEV/ ENEV) |
|---|---|---|---|---|
| 3.77 | 40.8 | 100 | 0.408 | 9.2 |
a The highest measured value for Canadian waters of 121 ng.L-1 (Lake Ontario) as reported in Boulanger et al. (2004)
b 10-day NOEC of 0.0491 mg.L-1 for the growth and survival of the aquatic midge (Chironomus tentans) as reported in MacDonald et al. (2004)
c An application factor of 100 was applied to account for lab to field variations and to convert an acute endpoint to a chronic endpoint
d A range of estimated exposure values in liver for a number of avian species were used (see Appendix 3)
e 21 week study ( increase in the incidence of small testes size and decreased spermatogenesis) for adult male mallards determined to be 10 ppm PFOS in feed. At this dose, the level of PFOS in liver (ww) was 60.9 µg.g-1
f An application factor of 100 applied for extrapolation from laboratory to field conditions and for intraspecies and interspecies variations in sensitivity, and extrapolation from the observed effects level to a no-effect level
g A range of estimated exposure values in serum for a number of avian species were used (see Appendix 3)
h In Canada, the highest mean PFOS concentrations in wildlife were reported in a study of polar bears from 7 locations. The highest Canadian concentrations were found in polar bear from South Hudson Bay (range 2000-3770 µg.kg-1 ww liver, mean 2730 µg.kg-1 ww liver) (Smithwick et al. 2005). This data was a re-analysis of polar bear samples from South Hudson Bay conducted by Martin et al. (2004) which reported concentration in polar bear liver of 1700->4000 µg.kg-1 ww liver, mean = 3100 µg.kg-1 ww liver.
i As no wild mammal studies were found, laboratory mammal studies were used as surrogates. The CTV for mammals was selected from a 2-year dietary rat study in which histopathological effects in the liver were seen in males and females at intakes as low as 0.06–0.23 mg.kg-1 bw per day and 0.07–0.21 mg.kg-1 bw per day, respectively (Covance Laboratories, Inc. 2002). Average values were determined for males and females, to establish LOELs of 40.8 µg.g-1 in liver and 13.9 mg.L-1 in serum.