Preliminary Study: Investigating Lead Exposure in Northern Canada and the Sahtú Region, Northwest Territories.

Elevated lead levels were measured in people from the Sahtú region in 2015-2019. When presenting these results to Sahtú communities, community members raised concerns regarding the sources of lead. A preliminary project to investigate sources of exposure to lead was completed. This dataset includes lead levels in hunter-shot birds (i.e., lesser snow geese, greater white-fronted geese, and Canada geese), fish (i.e., burbots) and water samples (surface water and municipal supply). From the water samples (n=30) collected in summer 2019 and 2020 at different points of the drinking water system, we observed that the water source with the most elevated lead concentrations was from the Mackenzie River at the pumping site, followed by the sample collected in a nearby wetland. Four tap samples were analysed and were below the Canadian Maximum Acceptable Concentration (MAC). From the fish (n=10) collected between December 2019 and January 2020, only one muscle sample had detectable level of lead. The liver sample tended to show higher lead level than muscle, with an average of 0.005 mg/kg. Local harvesters collected birds (n=20) during regular harvesting season in May 2021. None of the hunters reported using lead ammunition for harvesting. The lead levels in breast and gizzard were low, and levels in the majority of breast muscle samples were under the reporting limit. The average of lead concentration in gizzard was slightly higher than in breast meat. Those findings suggest low levels of lead in water, fish, and birds in the region. This project provided limited data to assess sources of lead for people living in the Sahtú region. Further work is required to assess all sources of lead and promote safe traditional/country food consumption.