Carleton University’s Paul Villeneuve, associate professor in the Department of Health Sciences, has released new research underlining the dangerous effects of fine particulate matter, also known as PM2.5, in the air we breathe.
“It’s well known that air pollution is related to negative health outcomes,” said Villeneuve. “The question is, at what levels of PM2.5 exposure do we actually see those adverse effects? Our study found harmful effects even at low levels of exposure to fine particulate matter that are commonly found in Canadian cities.”
Villeneuve and his team found that increased exposure to PM2.5 led to a heightened risk of mortality due to cardiovascular disease by about 30 per cent.
Canada has low levels of air pollution relative to other countries, making it a good spot to examine the effects of PM2.5. A previous study, which followed people living in areas of the country with varying levels of PM2.5, also found that exposure to fine particulate matter increased risk of respiratory mortality. But that study did not include other important disease risk factors that could have obscured the results, such as smoking, obesity, history of cancer and other variables in each of the subjects. Villeneuve’s study was able to control for these factors.
“The fact that we have more detailed data on the characteristics of our participants, and we’re coming to the same conclusions, leads us to believe that this is an important association that isn’t being distorted by factors like obesity, smoking and more,” said Villeneuve.
The study used data from more than 89,000 women who enrolled in the Canadian National Breast Screening Study between 1980 and 1985. The team derived long-term exposure to PM2.5 from satellite observations, and linked participants’ information records to national mortality data to ascertain causes of death between 1980 and 2005.
This study will have policy and research implications, said Villeneuve.
“Various countries and international institutions like the World Health Organization have recently lowered their standards for PM2.5. Studies like this show that health effects are occurring at lower air pollution levels than previously thought which means that the health impacts are being underestimated. In terms of setting priorities, studies like this one will help us identify where limited research funds should go.”
Villeneuve worked on the project with researchers from Health Canada, the University of Toronto and Dalhousie University. The paper was published in the journal Epidemiology in April 2015.