Pierre River Mine Project

HEALTH AENV SIRS 79 – 89
Neurotoxicants
Section 14.1
• The high degree of conservatism incorporated in the predicted fruit and
vegetable concentrations through the use of the 95UCLM soil concentration
to represent regional background soil concentrations of manganese.
• Cabin and Aboriginal residents were assumed to obtain all (100%) of their
food (traditional and non-traditional) from local, natural sources over their
lifetimes, and not supplement their diet with any foods from the local grocery
store.
• Estimates of daily exposure in the region remain within the range of typical
human exposures (Health Canada 1987, WHO 2004).
• The degree of conservatism incorporated in the oral exposure limit.
The RQ values for the “neurotoxicants” mixture increased from 8.7 in the HHRA
to 9.9 due to the inclusion of non-traditional foods in the multiple pathway
assessment.
For the following reasons, the likelihood for people living in the region to
experience neurotoxicity as a result of the project or planned developments is
low:
• No change was predicted between the Base Case and Application Case RQ
values.
• All (100%) of the RQ values under the Application Case and the PDC were
associated with the Base Case.
• Risk quotients associated with methyl mercury, which is still the primary
contributor to the mixture RQ values, are conservative estimates based on the
assumptions made in the HHRA (see EIA, Volume 3, Section 5.3.3.3).
• Most of the RQ values under the Base Case were still the result of assumed
fish consumption.
• It was assumed that residents would obtain all (100%) of their food,
including fish, from the local, natural sources over their lifetimes.
Reproductive and Developmental Toxicants
The RQ values for the “reproductive and developmental toxicants” mixture
increased for cabin residents from 8.9 to 9.0 in the HHRA to 9.2 to 9.3 due to the
inclusion of non-traditional foods in the multiple pathway assessment. Similarly,
the RQ values for Aboriginal residents increased from 8.8 to 9.2.
For the following reasons, the project is not likely to result in adverse health
effects associated with exposure to reproductive and developmental toxicants in
the region:
14-32 Shell Canada Limited April 2010
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