|
|||||
|
|
Exposure of aboriginals in British Columbia to methylmercury in freshwater fish: A comparison to reference doses and estimated thresholds |
|
| Authors: | Sara M. Hoover Ryan A. Hill Tom A. Watson |
| Affiliation: | 1. Triton Environmental Consultants, Ltd. , Richmond, B.C.;2. Golder Associates Ltd. , 4260 Still Creek Drive, Suite 500, Burnaby, B.C., Canada , V5C 6C6 Phone: (604) 298–6623 Fax: (604) 298–6623 E-mail: shoover@golder.com;3. Triton Environmental Consultants Ltd. , #120–13511 Commerce Parkway, Richmond, B.C., Canada , V6V 2L1 Phone: (604) 279–2093 Fax: (604) 279–2093 E-mail: rhill@triton‐env.com |
| Abstract: | We have analyzed the methylmercury exposures of native women consuming fish from a reservoir and two lakes in British Columbia. Probability density functions representing methylmercury dose were generated using reasonable distributions for exposure parameters. Sensitivity analyses were performed to assess the impact of alternative parameter values on the exposure estimates. The effect of ignoring variability and uncertainty in exposure was also assessed. Calculated mean daily doses of methylmercury for the target populations were compared to the estimated average dose for the general population. We also determined the percentages of the native women populations with exposures exceeding current guidance values as well as published thresholds for neurological effects. The analysis demonstrates the importance of better characterizing the low dose effects of methylmercury, as the predicted doses fall in the range of recommended maximum daily doses but well below the higher estimates of the effect threshold. |
| Keywords: | Probabilistic exposure assessment hydroelectric reservoir reference dose |