Role of air quality in asthma prevalence under the microscope

The Sainte-Anne Bridge in Chicoutimi, Saguenay, QC, on a bright winter's day, with the Saguenay river mostly frozen over.
The Sainte-Anne Bridge in Chicoutimi, Saguenay, QC, one of the study sites.

Research project to examine air quality at sites including in Canada’s North

A new study co-led by a Department of Health and Society Professor aims to shed light on the role that the complex interplay between airborne microbes and air pollutants have in causing or preventing the triggers of asthma by turning the focus on Canada’s North.

Asthma is the most prevalent chronic respiratory illness in Canada, affecting over 3.8 million Canadians, approximately a quarter of which are children. Studies show asthma is more prevalent in urban locales than rural ones, and growing up in areas with diverse microbial communities such as farmland can decrease the likelihood of developing asthma, by helping human-associated microbes train the immune system.

However, few studies have looked at prevalence of the illness in Northern Canada.

Assistant Professor Élyse Caron-Beaudoin is co-principal investigator of the project along with Catherine Girard of Université du Québec à Chicoutimi. The project recently received $200,000 of funding from Natural Sciences and Engineering Research Council of Canada (NSERC) and Fonds de Recherche Québec – Nature et Technologies.

The project looks at how air quality contributes to asthma in four regions across Canada: Scarborough, Ontario; Saguenay, Quebec; Kuujjuarapik, Nunavik; and Resolute Bay, Nunavut. These four locations are located along a gradient varying in vegetation and land use, as well as population density ranging from 680,000 people in Scarborough to 198 in Resolute Bay.

“It’s a really unique project in the sense that we’re pushing the boundaries of toxicity testing and really looking at interactions between two completely different things we find in air – pollutants and microbes,” says Prof. Caron-Beaudoin.

Prof. Caron-Beaudoin’s PhD student, Matthew Day, is in charge of developing a cellular model that mimics the asthmatic lung by combining together different types of cells found in the lung from donors diagnosed with asthma. Prof. Girard’s team will measure air pollutants as well as take samples of the microorganisms prevalent in each of the four areas. Prof. Caron-Beaudoin’s team will then expose these to the lung cellular model, and measure oxidative stress and inflammation – known triggers of asthma. They expect the diversity of airborne microbes in the environment at the Northern sites will have a protective effect against these triggers.

Children in Inuit communities, for instance, tend to suffer from respiratory infections and illnesses due to socio-economic factors. Despite this, prevalence of asthma seems to be lower in these communities, although it is very likely underdiagnosed.

“There are a lot of confounding factors in the North,” adds Prof. Caron-Beaudoin, “For example, living in a home in need of major repair, overcrowding and mold in houses are all known risk factors of asthma. It’s a bit messy just to understand all the actors playing a role in the incidence of asthma in these regions. What we want to see is: does the air quality profile in these regions and have an effect on the mechanisms which can trigger asthma? And then we want to see if we can identify species of microorganism which are protective of asthma in the different microbiomes, and if they counterbalance the triggering effect of air pollution.”

The project has funding for three years, and will be additionally hiring two MSc students to contribute, as well as well as local youth researchers at the test sites.

For more information contact David Blackwood, Research Communications Coordinator, Department of Health and Society, University of Toronto Scarborough at