Toronto Air Quality Ranks Among Worst in the World Amid Wildfires

Smoke from wildfires burning across both Ontario and Quebec blanket the skyline in Kingston, Ont., on June 6, 2023. (Lars Hagberg/The Canadian Press)

In a top 100 ranking of poor air quality and pollution in cities around the world, Toronto ranked sixth place for unhealthy air Wednesday.

The IQ Air Quality Index produces a daily live, major city ranking, and on June 28 at 7 p.m. ET, Toronto took one of the top spots on the list, with smoke from forest fires in parts of northeastern Ontario and Quebec hanging over the city.

For a brief period around 4 p.m. local time, Toronto was in first place as the worst city in the world for air quality, followed by Dubai in the United Arab Emirates.

The thick smoke prompted Environment Canada to issue a warning for the Toronto area on June 28, advising that smoke plumes from fires over northeastern Ontario and Quebec were “resulting in deteriorated air quality.” Those “very high levels of air pollution” are expected to continue for the remainder of the day, improving in some areas by the end of the week.

The city of Toronto made changes to programming in response to the air quality, warning that “certain individuals, including seniors, pregnant individuals, infants and young children and those with chronic heart or lung conditions are at a higher risk of health problems when exposed to air pollution.”

“Exposure to air pollutants can result in various symptoms, such as irritated eyes, increased mucus production, coughing and difficulty breathing,” said the city, advising people to limit their outdoor activities and close their windows and doors, being mindful of exposure to excess heat.

Toronto suspended all outdoor activities at its early childhood learning and daycare centres, and moved city-run outdoor museum programs indoors on June 28.

As the day progressed into evening, Toronto trailed behind Chicago in first place, Dubai in second place, and Delhi, India, in third. U.S. cities Detroit and Minneapolis took fourth and fifth place respectively, largely due to drifting smoke blowing in from Canada’s out-of-control wildfires.

The federal weather agency said air quality and visibility due to wildfire smoke “can fluctuate over short distances and can vary considerably from hour to hour.”

Canada has an Air Quality Health Index (AQHI) as part of Environment Canada, which reports current air quality based on health risks. On June 28, the index was reporting high risks with regard to air quality in Toronto, Ottawa, and Montreal.

According to the Environmental Protection Agency’s AirNow.gov site, on June 27, parts of Illinois, lower Michigan, and southern Wisconsin had the worst air quality in the United States, while Chicago, Detroit, and Milwaukee had air quality categorized as “very unhealthy.“

Fires burning in northern Quebec, in combination with a low pressure system over the eastern Great Lakes, are to blame for smoke travelling into northern Michigan and across Wisconsin and Chicago, according to meteorologists.

Between Jan. 1 and June 26, data from the Canadian Interagency Forest Fire Centre indicates that 76,129 square kilometres of Canadian land including forests has burned across the country. As of June 28, there were 482 active fires across the country, including 240 burning out of control.

One-quarter of the fires currently burning are in Quebec.

According to Europe’s Copernicus Atmosphere Monitoring Service, smoke from Canadian wildfires is drifting across the Atlantic Ocean to Western Europe.

“Record levels of emissions generated by the intense wildfire activity across Canada in May and June are having a major impact on air quality, both in Canada and further afield,” the weather service said in an update on June 27.

“The significant wildfire activity witnessed in Canada in May has continued and intensified throughout June ... with significant long-range transport of smoke crossing the Atlantic and reaching Europe,” said Copernicus.

Environment Canada indicated that smoke from wildfires in forests and grasslands can be a major source of air pollution for Canadians.

“The fine particles in the smoke can be a serious risk to health, particularly for children, seniors and those with heart or lung disease. Because smoke may be carried thousands of kilometres downwind, distant locations can be affected almost as severely as areas close to the fire,” said the department.