Canada’s 2023 Wildfire Season: An Unprecedented Environmental Catastrophe

A study has found that contaminated mining sites increase the risks associated with fires.
The 2023 wildfire season in Canada was the most destructive ever recorded, and a new study suggests the impact was unprecedented. The research found that four wildfires in mine-impacted areas around Yellowknife, Northwest Territories, potentially contributed up to half of the global annual arsenic emissions from wildfires.

The work, led by researchers at the University of Waterloo and Nipissing University, is the first to calculate the amount of arsenic that was stored in areas at high risk of wildfires around Yellowknife. Looking at data from the past five decades, the team estimates the 2023 wildfires potentially released between 69 and 183 tonnes of arsenic.

Arsenic, a potent toxin, that the World Health Organization associates with diabetes, cardiovascular disease, various cancers, and infant mortality, can be transformed by wildfire and released into the environment from the soils that normally sequester it.

The Growing Risk of Wildfires
Given that the frequency and severity of wildfires are expected to increase because of climate change, the researchers caution that in any regions in the world where annual wildfires intersect with past or present mining and smelting operations, future fires could present a major 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,” said Dr. Owen Sutton, a postdoctoral fellow in the Faculty of Environment at Waterloo.