Investigating lead exposure in northern Indigenous communities of the Sahtú region, Northwest Territories, Canada

Lead (Pb) exposure due to game meat consumption, harvesting practices, untreated water consumption, and resource-development pollution poses potential health risks to northerners and Indigenous People. The sources of elevated Pb exposure observed in the Sahtú Dene and Métis Land Claim Settlement, Northwest Territories, were unknown and human biomonitoring results warranted further investigation. This community-driven project aimed to: 1) investigate Pb levels in water, fish, and game birds from the Sahtú region, 2) document the use of Pb-containing ammunition for harvesting, and 3) identify communication priorities to reduce Pb exposure in the region. Interviews with store staff on availability of Pb-containing ammunition, surveys on hunting practices with Indigenous harvesters, and mixed investigation methods (radiography, mass spectrometry) to assess Pb levels in water, game birds, and fish were completed (2019–2023). Water samples (n = 90) were below the Canadian Maximum Acceptable Concentration for Pb (5 µg/L). Game bird muscle (n = 34) and fish muscle (n = 10) contained Pb levels well below regulatory limits for commercial food, while game bird liver (n = 12) showed elevated concentrations (max. 7.53 mg/kg), exceeding the recommended level (0.5 mg/kg). Eleven percent (11 %) of the responding harvesters (n = 19) mentioned having used Pb-containing ammunition for game bird hunting, as well as other animals, in the previous two years. Ongoing use of Pb-containing ammunition is suspected. Uncertainty remains regarding exposure pathways, underscoring the need for additional sample collection (e.g. soil, house dust) and biomonitoring, community engagement, and culturally appropriate health messaging for transitioning to non-toxic ammunition.