Study links 2023 Canadian wildfires to more than 85,000 premature deaths
A new study estimates that a staggering number of people around the world likely suffered an early demise due to smoke from Canada's record-breaking wildfire season in 2023
A newly released study warns that wildfire smoke can have widespread deadly consequences, suggesting smoke from Canada’s 2023 wildfires may cumulatively contribute to more than 85,000 premature deaths worldwide.
The paper was published Sept. 10 in the scientific journal, Nature, and details an extensive analysis of the impacts of the 2023 season, which saw more than 6,000 fires burn more than 17 million hectares of land as per current estimates.
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Using data from satellites, ground observations and atmospheric modelling, it estimates 354 million people were exposed to dangerous, (as per World Health Organization (WHO) guidelines) daily levels of PM2.5 air pollution in North America and Europe as a result of the smoke from those fires.
That smoke exposure, the study posits, potentially contributed to 5,400 acute deaths and 64,300 chronic deaths in those regions, and another 17,800 chronic deaths in regions like the Middle East, North Africa and Asia.
Fine particulate matter, or PM2.5, represents the most significant health risk from wildfire smoke exposure. It’s made up of different types of carbon resulting from combustion, in addition to other organic compounds and metals. The tiny particles are easily inhaled and can even be absorbed into the bloodstream.
Michael Brauer, a professor of population and public Health at the University of British Columbia (UBC), co-authored the study, which was a collaboration between Chinese, Canadian and American researchers.
He cautions that while these figures are statistical estimates, policymakers, health-care officials and the general public should be aware of the findings.
“This is really one of the first analyses that has been done about an individual fire season looking at the global impacts on exposure of populations and on health impacts,” says Brauer.
“What we’ve done is combine information from detailed studies that have been done previously where we know that if smoke goes up by an ‘x’ amount, this is the increase in deaths that we’re going to see in a given population.”
Brauer explains that the “acute deaths” mentioned in the study would be related to a single severe smoke exposure event and would occur in those who have a pre-existing condition like a heart or chronic lung disease. “Chronic deaths” refer to the implications on mortality of accumulated exposure over time.
While they can be costly, home air purifiers are one method of reducing exposure to PM2.5 when indoors. (Connor O’Donovan/The Weather Network)
“When we have pollution events, we clearly see an increase [in deaths]. We took data from a study that was done in 700 different locations around the world to study that relationship. When smoke goes up on that day, how many more people die on that day,” he explains.
“The other bit, what we’re calling chronic deaths, is the contribution of smoke occurring over a season to accelerated aging or progression of diseases. These aren’t from the day of the event, but from accumulated exposure over months and years. It could be somebody who’s dying at 67, who would have lived to 70.”
Health Canada, meanwhile, notes “there is no recognized threshold of health effects for outdoor PM2.5 regardless of where exposure occurs” and highlights health impacts ranging from headaches, dizziness and irritations, to stroke, heart attack and premature death.
Brauer points out that the study assumes significant portions of the population aren’t making safety adjustments when smoke is present, such as altering activity levels, wearing a mask cable of filtering out particulate matter, like an N95, while outdoors or employing an effective air purification system.
A recently released study shines a concerning light on how significant and widespread the impacts of wildfire smoke exposure can be. (Connor O’Donovan/The Weather Network)
That’s why, with forest fires being a permanent fixture of life in Canada and abroad, he hopes studies like this one can help improve awareness of the risks, inform health policy and programs, and help people live safely with smoke.
“I do hope that if I’m talking to you [in] five or 10 years from now, when we have another horrible smoke season like 2023, we won’t have these kinds of impacts.”