Cadmium and Mercury Exposure among Dene/Métis Communities of the Northwest Territories, Canada

Abstract

In northern Indigenous communities, eating traditional foods (which include locally harvested wild game, fish, game birds, and plants) is associated with improved nutritional status. However, traditional foods can occasionally increase human exposures to contaminants. To mitigate potential risks from elevated contaminant levels in fish and wildlife, public health officials regularly respond to the results from environmental monitoring programs by designing notices that advise individuals to limit their consumption of particular traditional foods. For example, elevated mercury (Hg) levels in Walleye, Northern Pike, and Lake Trout in some subarctic lakes led to the release of a series of consumption notices by the Government of the Northwest Territories Department of Health and Social Services. Also, high levels of cadmium (Cd) in the organs of moose from the Southern Mackenzie Mountains, Canada resulted in consumption notices recommending people to limit their consumption of kidney and liver of moose harvested from this region.Since 2016, a community-based human biomonitoring project has been run in nine Dene/Métis communities of the Dehcho and Sahtú regions of the Northwest Territories Mackenzie Valley (n=538). This project included dietary assessments (e.g., 24-hour Recall, Food Frequency Questionnaire) as well as hair, urine and blood sampling to characterize contaminant exposures among participants. Although Hg and Cd levels in traditional foods from the Northwest Territories are occasionally elevated, the results from this biomonitoring research show exposures to these metals to be generally similar to those observed in other populations in Canada. These results are supporting ongoing efforts at the community and territorial level to design follow up plans in response to environmental monitoring data.