Alberta researchers are studying the living organisms lurking in wildfire smoke

If you’ve spent time outside in virtually any part of Canada this summer, you’ve likely been choked by wildfire smoke. But just how harmful is that smoke? Is it similar to inhaling, say, second-hand cigarette smoke, or is there something even more sinister wafting in those fumes? Researchers are trying to find out. 

“You’d think fire is going to kill everything that’s alive, but … there’s pretty reasonable scientific evidence that suggests microbes could live.”

Christina Thornton,
University of Calgary

Christina Thornton is one part of a multipronged series of research projects bringing together the University of Calgary, University of Alberta (U of A), and Queen’s University to study the microbiome—that’s millions of tiny organisms like bacteria, viruses, and fungi that live together in a specific habitat—that exists within wildfire smoke. A microbiologist by trade and practicing respirologist with the Cumming School of Medicine, Thornton’s project is part of an emerging field called pyroaerobiology. Researchers in the field are trying to understand what microbes and chemicals exist in the combusted smoke lingering in our atmosphere. 

Thornton’s project, which she leads collaboratively with the U of A’s Ran Zhao, and which builds upon a prior project with Zhao and Queen’s University’s Paul Kubes, recently received $250,000 from the federal government’s New Frontiers in Research Fund (NFRF) tied to understanding the makeup of the wildfire smoke that now blankets much of the planet each summer in hopes that more effective medical treatment can be developed. That funding comes on the heels of a prior, $2-million grant from the Canadian Institute of Health Research for Thornton’s work with Kubes. 

“At the end, what we hope that we’ll have is a clear workflow standard operating procedure, as well as a sort of fingerprint of what wildfire smoke looks like both in terms of chemical and microbial composition,” Thornton said. 

Inspired by disaster

Thornton and her colleague’s project was conceived three years ago during the 2023 wildfires in Western Canada. It was the most severe fire season in living memory for Canada, and it caused the three academics to wonder how dangerous the smoke they were inhaling was. 

“We know wildfires are bad: clearly there are chemicals and particles … we are breathing in. But do we know if there’s anything else we’re breathing in?”

As it turns out, there’s a lot more than just ash, soot, and PM2.5— the ultra fine particulate matter that gets caught in our lungs—in that smoke. According to Thornton, smoke composition from wildfires can include things like fungal spores and microbial agents that haven’t historically existed in aerosol form, meaning there’s no basis for what impacts they might have when inhaled. 

“You’d think fire is going to kill everything that’s alive, but … there’s pretty reasonable scientific evidence that suggests microbes could live. And, what happens is when they’re exposed to these extremes of temperature, they can make spores, whether bacterial or fungal, and those spores can be dispersed and potentially inhaled,” Thornton said. 

That carries all manner of potential implications, from associations with cardiovascular disease and stroke, to exposure to potentially immune-system-influencing antigens, according to Thornton. 

“Microbes carry their own DNA,” Thornton said. “Antibiotic-resistant genes are present in these bugs. We don’t know what those are doing. If they’re carrying antimicrobial resistance and we’re breathing them in, that may have implications for how we treat patients.”

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Another study, out of the US, found associations between wildfire incidents and occurrences of respiratory fungal infections. 

To find those microbes and chemicals, the team uses high-volumetric air samplers to capture wildfire smoke, analyze those samples, and develop microbial communities that can be grown and studied. They’ve also made use of the Government of Canada’s burn lab, located at the Northern Forestry Centre in Edmonton, to burn natural components in a controlled setting and measure the outcome. 

A growing field of study

Thornton’s work is part of a growing field of research surrounding wildfires and their implications on human health. At U of A, in the Faculty of Engineering, assistant professor Haoran Yu is studying the ways airborne particulates enter indoor spaces and move through the air, as well as the chemical composition of smoke. Further east, the University of Manitoba is preparing to open the AirSAFE Lab, a multidisciplinary research centre on the health impacts of wildfire smoke. That centre is slated to open later this year. 

It’s a welcome effort, because, as Thornton says, the impacts of wildfire smoke are widespread, expensive, and not going away anytime soon. 

“We’re already in a strained healthcare system … it doesn’t take much to tip things over,” she said. “[Wildfire smoke] has healthcare costs, burdens on the system, increased resources, and we don’t have clear recommendations for what to do or clear guidance for what to do.”

BetaKit’s Prairies reporting is funded in part by YEGAF, a not-for-profit dedicated to amplifying business stories in Alberta.

Image courtesy Open Journalism Network. Photo by InOldNews/Katherine KY Cheng.