Montreal was engulfed by a thick cloud of smog on Sunday as wildfires raged in northern Quebec, making it the most polluted city in the world, according to a Swiss technology company that monitors air quality.
IQAir ranked Montreal first among major cities affected by pollution, with an air quality index (AQI) of 195, followed by Sao Paulo, Brazil (164) and Lahore, Pakistan (125).
The smog was caused by more than 80 fires burning in Quebec, covering over 100,000 hectares of land. The smoke also affected other parts of the province and eastern Ontario, triggering smog warnings from Environment Canada.
Several outdoor events were cancelled due to the health risks of exposure to smoke. These included triathlons in Montreal and Mont-Tremblant, rugby competitions in Beaconsfield, Laval and Quebec City, and Fête nationale festivities in Pointe-Claire.
“The priority is always athletes’ health, and I’m proud that we can stop the event when necessary so that athletes don’t have health problems in the weeks and months to come,” said Emy Legault, an elite triathlete who would have competed in the mixed relay race in Montreal.
Dr. Jean-Pierre Trépanier, the public health director for Laval, said he recommended school boards to keep children indoors on Monday and Tuesday.
“It’s quite an uncommon event. It’s the first time I’ve recommended that in 15 years of practice,” he said.
Experts say exposure to wildfire smoke can cause a litany of health issues, such as an elevated pulse, chest pain, and inflammation in the eyes, nose and throat. Fine particulate matter known as PM2.5 can penetrate deeply into the lungs and bloodstream and worsen conditions such as asthma and heart disease.
“That size is really important because can penetrate really deeply and wreak havoc on the body,” said Dr. Vijay Limaye, a climate and health scientist at the National Resources Defense Council.
Vulnerable groups such as children, pregnant people, older adults and those who are immunocompromised or having pre-existing conditions are particularly at risk from the poor air quality.
“Ideally on days like today, you should stay inside with the windows closed and the air conditioning on. If you have HEPA filters in your house, turn them on. Avoid exercising or heavy work outdoors on poor air quality days,” said Dr. Shawn Aaron, a professor in the department of medicine at the University of Ottawa.
– Poor air quality in Montreal from Quebec wildfires forces event cancellations, CBC News, Jun 25, 2023
– Canada wildfires: US East Coast sees worst air quality in years, BBC News, Jun 8, 2023
– Public security ministry warns Quebec forest fires could worsen, Ottawa Citizen, Jun 24, 2023
– What does all this wildfire smoke in southern Quebec mean for your health?, CBC News, Jun 6, 2023