Study Alerts to Unprecedented Arsenic Release from Wildfires in Yellowknife

The wildfire season of 2023 has been identified as the most devastating ever recorded in Canada, with new research highlighting its unprecedented impact. A study conducted by researchers from the University of Waterloo and Nipissing University reveals that wildfires in areas affected by mining around Yellowknife, Northwest Territories, may have contributed significantly to global arsenic emissions. The study estimates that four of these wildfires potentially released between 69 and 183 tonnes of arsenic, which could account for up to half of the annual global emissions from wildfires.

This research is the first to quantify the arsenic stored in high-risk wildfire areas around Yellowknife. Arsenic, a highly toxic element linked to serious health issues such as diabetes, cardiovascular diseases, various cancers, and infant mortality, can be mobilized and released into the environment by wildfires. Typically, arsenic is contained in soils, but wildfires can transform and disperse it.

As climate change is expected to increase both the frequency and intensity of wildfires, the researchers warn that regions with past or present mining and smelting operations face significant risks. Future wildfires in these areas could release stored toxins back into the environment.

“Yellowknife’s long history of mining has led to arsenic accumulation in the surrounding landscape,” said Dr. Owen Sutton, a postdoctoral fellow in the Faculty of Environment at Waterloo. “However, Yellowknife is not unique; Canada has numerous industrially contaminated sites vulnerable to wildfire.”

The amount of arsenic released by wildfires is influenced by several factors, including fire temperature, burn depth, and soil type. “Our research highlights the urgent need for a collaborative approach involving wildfire scientists, chemists, environmental experts, and policymakers,” stated Dr. Colin McCarter, a professor at Nipissing University and Canada Research Chair in Climate and Environmental Change.

The study also found that wetlands pose the greatest concern for arsenic emissions due to their ability to store contaminants more than forests. The researchers plan to continue their work by quantifying toxins in northern peatlands and investigating the release of other metals from these landscapes.