As wildfires continue to ravage parts of Canada, experts are sounding the alarm regarding the potential toxicity of wildfire smoke in Manitoba. Colin McCarter and Michael Schindler, both researchers in environmental science, have raised concerns that the smoke may carry contaminants from the region’s polluted soil, putting local populations at risk. They caveat their findings to highlight that much more research is needed to grasp the gravity of this emerging sustainability catastrophe.
The toxicity of wildfire smoke can vary widely depending on a number of factors. McCarter noted that a number of factors influence the harmful toxins emitted into the air. These factors include the temperature of the fire, what kind of peatland is burning, and the climate in the region. In Manitoba, where peatlands—vital carbon storehouses—cover approximately one-third of the province, these factors could lead to an unprecedented release of harmful pollutants.
The Threat of Historical Contaminants
The implications of these wildfires reach far beyond immediate air quality concerns. McCarter further explained that these fires would release the pollution that has been held in Manitoba’s rich soil for thousands of years. This especially wrings out all of the toxic chemicals that result from over a century of resource extraction in northern territories.
According to Schindler, lead, zinc, mercury and selenium are the most worrisome contaminants. Environmental toxic metals like chromium, nickel, and manganese latch onto the smaller particles found in wildfire smoke. Therefore, they can more easily evade into human lungs. He stated, “The particles in wildfire smoke are literally the Trojan horse for contaminants.”
Environment and Climate Change Canada is quick to point out that the Hudson’s Bay Mining and Smelting Company smelter in Flin Flon was Canada’s largest atmospheric mercury emissions source. This smelter continued to run until it was closed in 2010. Today, we continue to live with the impacts of that legacy contamination. These collaborative investigations have shown high concentrations of mercury and other trace metals in sediment cores, soil humus, vegetation, and peat matrices in a wide swath of Manitoba.
Climate Change and Peatlands at Risk
Peatlands are at elevated risk not only due to climate change, but the factors that heighten wildfire events. McCarter explained that of all the ecosystems on earth, peatlands are specifically extraordinary at sequestering these toxic metals. They are growing more susceptible than ever as our landscapes are drying out. This vulnerability poses an acute threat that McCarter describes as a “pollution time bomb.” It endangers our country’s land, waters, environment, and public health.
“It was a very hot fire as far as I understand it. The trees were burned down to the roots and the burning continued into the peat underneath,” said Dave Price, an environmental scientist. He stressed the need to track the sources of smoke and identify the toxins in that smoke.
McCarter underscored that researchers are still trying to determine a direct relationship between peatland contaminants and the hazards they pose. This field of research is still developing. “Trying to make that link there… from what’s in the peatlands to what is the risk is still a very active part of my research,” he said.
The Need for Monitoring and Research
This was not news to either McCarter or Schindler, who both support greater monitoring of wildfire smoke and related health effects. As Schindler made starkly clear, these contaminants have a serious effect on local communities such as Flin Flon. He emphasized the immediate need for more integrated studies to assess the broader public health dangers.
“It’s huge amounts of wildfire smoke, and you get those metals coming in…but it will dilute over a long distance,” Schindler explained. He warned that some pollutants could remain targeted. The rest could go mobile and wreak havoc well outside of current fire perimeters.
