Canada’s air quality worse than U.S. due to wildfires

Of 15 most-polluted cities, 14 were north of border

Canada’s air pollution levels last year were worse than those in the United States for the first time since an air-quality firm started publishing its assessments in 2018.

The sixth World Air Quality report published Tuesday by Swiss firm IQAir says raging wildfires were a major influence on Canada’s drop in air quality in 2023.

While the report found Canada on average still has some of the least polluted air, public-health experts have repeatedly warned about the health dangers of more intense wildfire seasons, fuelled by humancaused climate change.

Health Canada estimates air pollution contributes to 15,300 premature deaths every year in Canada. Wildfire smoke exposure is also strongly linked to chronic conditions, such as asthma, and increases in respiratory emergency room visits.

The U.S. typically dominates the World Air Quality report’s list of 15 most polluted cities in both the U.S. and Canada, with Canadian cities appearing on the list just three times since the first assessment was published in 2018.

But roles reversed last year as thick clouds of wildfire smoke descended over the country. The report says Canada made up 14 of the 15 cities on the list, dominated by Alberta and B.C., and topped by Fort McMurray, Alta., and Peace River, Alta.

The report aggregates monitoring data from sources around the world, including governmental and non-profit, on pollution known as PM2.5, fine particulate matter so small it can travel deep into lungs and pose a risk to human health. The data is then reported in units of micrograms per cubic metre, and held up against World Health Organization guidelines to keep concentration levels below 5.

Canada was less polluted than 92 of the 134 countries, regions or territories surveyed in the report, with annual concentration levels of 10.3, or about twice as high as the WHO guideline. Most polluted was Bangladesh, with 79.9, followed by Pakistan and India.

Health Canada estimates air pollution contributes to 15,300 premature deaths every year in Canada

JULIE JACOBSON THE ASSOCIATED PRESS FILE PHOTO Pedestrians pass the One World Trade Center in New York, amidst a smokey haze from wildfires in Canada last summer.