Reviewed by Lexie CornerJul 24 2024
A recent study reveals a consequence of Canada's devastating 2023 wildfire season. Researchers from the University of Waterloo and Nipissing University estimate that wildfires burning near Yellowknife, Northwest Territories, may have released a significant amount of arsenic—potentially contributing up to half of the global arsenic released by wildfires annually. The study has been published in Environmental Research Letters.
Previously, the amount of arsenic stored in these fire-prone areas around Yellowknife was unknown. This new research, analyzing data from the past five decades, suggests that the 2023 fires released an estimated 69 to 183 tons of arsenic. This raises concerns about potential environmental and health risks in the region.
Arsenic can be transformed by wildfire and released into the environment from the soils that typically sequester it. The World Health Organization links this potent toxin to diabetes, cardiovascular disease, multiple cancers, and infant mortality.
Given that the frequency and severity of wildfires are expected to rise due to climate change, the researchers warn that in regions of the world where annual wildfires intersect with past or present mining and smelting operations, future fires could present a significant risk for releasing stored toxins back into the environment.
Yellowknife has a decades-long history of mining, which has led to an accumulation of arsenic in the surrounding landscape. However, Yellowknife is not unique in this regard; Canada has many industrially contaminated sites that are vulnerable to wildfire.
Dr. Owen Sutton, Postdoctoral Fellow, Faculty of Environment, University of Waterloo
Numerous variables, including fire temperature, burn depth, soil type, and their combinations, affect the amount of arsenic released during wildfires.
While our research has raised the alarm on this issue, we will be the first to argue there is an urgent need for collaborative investigation by wildfire scientists, chemists, environmental scientists, and policy experts.
Dr. Colin McCarter, Professor, Department of Geography, Nipissing University
Dr. Colin McCarter is the Canada Research Chair in Climate and Environmental Change.
McCarter continued, “By integrating diverse fire management techniques, including Indigenous fire stewardship, we can hopefully mitigate these emerging risks to human and environmental health.”
Arsenic emissions from wetlands were found to be the most concerning due to their propensity to retain pollutants longer than forests. Going forward, they will keep measuring the amount of toxins that northern peatlands store and investigate the possibility of other metals escaping those environments. Dr. James Waddington, from McMaster University, also contributed to the work.
Journal Reference:
Sutton, O. F., et al. (2024) Globally-significant arsenic release by wildfires in a mining-impacted boreal landscape. Environmental Research Letters. doi.org/10.1088/1748-9326/ad461a