Risk Assessment of Dietary Lead (Pb), Cadmium (Cd), and Mercury (Hg) Exposure among First Nations People in Ontario, Canada - a Total Diet Study and Probabilistic Assessment

Abstract

This thesis quantified risks of lead (Pb), cadmium (Cd), and mercury (Hg) in the diet of First Nations peoples residing on-reserve in the province of Ontario, Canada. Data was obtained from the 2011-2012 First Nations Food, Nutrition, and Environment Study (FNFNES) and Health Canada to construct total diet studies and probabilistic assessments. Results indicated that the majority of the population is at low risk of exceeding the reference values for these contaminants. Average exposures of Pb and Hg were higher than the general Canadian population (1.7 and 1.6 times greater, respectively), whereas Cd was 59% lower than the Canadian average. The upper percentiles of the population exposure distributions were characterized for contributing food items to assist risk management strategies. For cadmium exposures, smokers had elevated exposures compared to non-smokers. Women of childbearing age had lower dietary MeHg exposures than the total population and were largely below the reference value.