Montreal study finds increased cancer and tumour risk due to wildfires

With wildfires in Quebec already exceeding 10-year averages in size and quantity, a new study out of Montreal suggests the health of those living near are at a greater risk of developing lung cancer and brain tumours.

Quebec's forest fire protection agency (SOPFEU) reports seven active forest fires in the province. The 146 this year is 41 more than the decade-average at the same time, and the 110.3 hectares burned is 26.2 more than the average.

B.C., by comparison, is monitoring eight active fires and has had 100 in 2022 so far.

SOPFEU spokesperson Melanie Morin said that the combination of dry weather, warmth, and unusually low humidity along with less vegetation, make for ideal conditions for fires to start.

"Most lawns are still yellow, trees have barely any leaves in them, so the sun can get through to the forest floor," said Morin. "All that makes for combustible for vegetation that is very easily ignitable until all that greenery comes in."

There is an open fire ban in many regions in Quebec.

Morin said that though crews have been able to keep the fires under control, SOPEFEU is noting multiple new fires per day.

"Obviously, people are not respecting the open fire ban," said Morin. "And that is causing us quite a bit of work. It's causing the municipal firefighters quite a bit of work, and it is putting people at risk."


A McGill University study published in The Lancet Planetary Health journal suggests the increased fire activity is something to be concerned about.

The study tracked 2 million Canadians over two decades to determine how proximity to forest fires influences cancer risk.

"Wildfires tend to happen in the same locations each year, but we know very little about the long-term health effects of these events," said McGill associate professor and study lead Scott Weichenthal, working out of the epidemiology, biostatistics and occupational health department.

The study says that those living within 50 kilometres of wildfires over the past 10 years have a 10 per cent higher incidence of brain tumours and a 4.9 per cent higher chance of getting lung cancer compared to those living further away from forest fires.

"Many of the pollutants emitted by wildfires are known human carcinogens, suggesting that exposure could increase cancer risk in humans," said Ph.D student Jill Korsiak.

As wildfires tend to happen in the same areas year-on-year, those in the region may be at risk.

In addition to negatively affecting air quality, wildfires also pollute soil, water and indoor environments, a release on the study says. Some pollutants do not last long, but others, such as heavy metals and hydrocarbons, stick around for a long time.

"Exposure to harmful environmental pollutants might continue beyond the period of active burning through several routes of exposure," said Weichenthal.

The researchers said more investigation is needed to understand the environmental pollutant mix caused by wildfires. 


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