Human Biomonitoring of and Determinants of Biomarker Levels for Contaminants and Nutrients in Old Crow, Yukon Territory

• Main Author: Drysdale, Mallory
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: University of Waterloo 2022
• Subjects: Indigenous; Toxicology; Contaminants; Arctic; Traditional foods; Exposure; Nutrients; Yukon; Canada; First Nations; Old Crow
• Online Access: http://hdl.handle.net/10012/19026

Traditional food is an important part of the diet for many Arctic residents, particularly First Nations, and is associated with some improved health outcomes, nutrition, and food security. However, these foods can also pose potential risks via exposure to certain contaminants, including those which are found at higher levels in the Arctic. Several large-scale human biomonitoring projects have been conducted in Canada, however, prior to the one herein, none have recruited participants living in the Yukon. This thesis used the results of a human biomonitoring clinic conducted in Old Crow, Yukon, in 2019 to respond to community questions and concerns regarding human exposure levels of contaminants and nutrients in the community, and how these levels relate to traditional food consumption and other lifestyle and demographic determinants. The clinic included the collection of hair, blood, and urine samples for the analysis of contaminants and nutrients, and the administration of dietary and health messaging surveys. This thesis compared results of the clinic those from reference populations and health-based guidance values. Levels of most measured contaminants and nutrients, including most metals (e.g. mercury, cadmium), and persistent organic pollutants (POPs) (e.g. polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT)) were similar in Old Crow to those in the general Canadian population and were below available health-based guidance values. Some contaminants and nutrients, including the metal nutrients manganese and cobalt, the toxic metal lead, and the pesticide hexachlorobenzene (HCB), were elevated in Old Crow relative to the general Canadian population. These contaminants and nutrients were analyzed further to identify potential local determinants of urine and blood levels. Generalized linear models were run to identify significant associations between blood and urine levels of these substances, with factors including demographics, lifestyle risk factors, and traditional food consumption. ...