Can wildfire smoke make you sick? How to stay safe amid air quality alerts, wildfire evacuations in Canada

With parts of Canada and the U.S. under air quality warnings, here's what to know about staying indoors, wearing a mask, and more tips to stay safe.

This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. Contact a qualified medical professional before engaging in any physical activity, or making any changes to your diet, medication or lifestyle.

The wildfire forcing thousands to evacuate from a northeast British Columbia town has doubled again in size as the blaze grows merely a few kilometres west of city limits. The Aurora Borealis shines overhead of a B.C. Conservation Officer Service vehicle near the junction of highways 97 and 77, as a wildfire burns in the background near Fort Nelson, B.C., in a Saturday, May 11, 2024, handout photo. THE CANADIAN PRESS/HO-Ministry of Water, Land and Resource Stewardship, *MANDATORY CREDIT*
Dangers of wildfire smoke inhalation are making headlines again as fires rage across Canada. On May 11, 2024, the Aurora Borealis was seen shining overhead of a B.C. Conservation Officer Service vehicle as a wildfire burns in the background near Fort Nelson, B.C. (THE CANADIAN PRESS/HO-Ministry of Water, Land and Resource Stewardship)

Wildfires are raging again across Canada, with around 90 fires currently burning and smokey conditions affecting western provinces. The situation has led to hazardous air quality conditions in Canada, extending into the United States for the first time this season.

In northeastern British Columbia, the Parker Lake Fire tripled in size over the weekend and has gotten closer to the community of Fort Nelson, that's now under an evacuation order. Meanwhile, in Alberta, an evacuation alert is in place for residents of the Fort McMurray area after new fire starts over the weekend. The province is also being impacted by the wildfire smoke from B.C., with officials saying: "We know the presence of wildfires and smoke in the region can cause a wide range of emotions. Many local public and professional mental health resources are available."

Environment Canada has issued air quality alerts for parts of B.C., Alberta, Manitoba, Saskatchewan, Northwest Territories and Quebec on Monday through Tuesday. "Wildfire smoke can be harmful to everyone's health even at low concentrations," it warned.

Warnings were also issued south of the border, in Minnesota, Montana, the Dakotas and Wisconsin due to the haze, urging people to stay indoors and avoid physical activity outside.

As the wildfire season kicks off, ways to protect ourselves from smoke are top-of-mind for many. Last year, Yahoo Canada spoke to a top respirologist in Toronto, who weighed in on the impact of smoke on our lungs, and what to do to stay safe. Read on for everything you need to know.


Smoke from wildfires blankets the city as a couple has a picnic in Edmonton Alberta, on Saturday May 11, 2024. THE CANADIAN PRESS/Jason Franson
Smoke from wildfires blankets the city as a couple has a picnic in Edmonton, Alta., on Saturday, May 11, 2024. THE CANADIAN PRESS/Jason Franson

Dr. John Granton, a respirologist at the Toronto General Hospital (University Health Network), told Yahoo Canada wildfires cause air pollution that can have a far-reaching effect on human health.

Small air pollutant particles in the smoke, called the PM2.5 particles, are "where a lot of the toxic stuff lives," Granton explained.

"That's not filtered by your upper airway, that gets access to your lower airway and into your bloodstream even — and that's where the danger lies.

"That can cause asthma attacks, can cause heart attacks, can contribute to hospitalizations and has long-term health outcomes."

Even just the smell could cause problems to some, he said.

"Being in smog all day long, the smell bothers people; it can cause irritation of the upper airway, some of the larger particles can cause irritation, and cause symptoms. People [who] have chest symptoms or asthma, it can make them feel worse."

Granton said smoke isn't easy to escape, but there are some things people can do try and stay safe.


According to Granton, "there's not a lot of data to support the health benefits of masking" when it comes to safety from wildfire smoke. But, he said there is research looking into the effectiveness of filters.

"Cloth masks or scarves and things are not effective at all," the doctor claimed.

But, surgical masks and N95 filter masks "tend to filter those smaller particles," he added, "apparently some of those masks are effective."

A cyclist wears a mask due to poor air quality conditions as smoke from wildfires in Ontario and Quebec hangs over Ottawa on Tuesday, June 6, 2023. THE CANADIAN PRESS/Sean Kilpatrick
A cyclist wears a mask due to poor air quality conditions as smoke from wildfires in Ontario and Quebec hangs over Ottawa on Tuesday, June 6, 2023. THE CANADIAN PRESS/Sean Kilpatrick

Granton said "they're not going to filter the gases," though, and there are studies that question whether masks that aren't properly fitted would actually help in the real world.

"Whether or not that has a direct health benefit is speculative right now," Granton explained.

However, he said it "may be reasonable" for those who have underlying health conditions and those who have to be in the hotspots of the pollution to wear one.

"If you have to be outdoors and doing things, then wearing that sort of mask to protect you would be sensible."


Though filtration masks could aid in protecting your lungs from smoke, the number one recommendation from experts is to stay indoors.

A woman walks her dog along the Ottawa River in Ottawa as smoke from wildfires obscures Gatineau, Que., in the distance on Tuesday, June 6, 2023. THE CANADIAN PRESS/Sean Kilpatrick
Canadian experts are advising to stay indoors to protect yourself from wildfire smoke. (THE CANADIAN PRESS/Sean Kilpatrick)

According to Health Canada, the following measures should also be taken:

  • Reduce sources of indoor air pollution (smoking, vacuuming, burning candles, wood stoves)

  • Prevent infiltration of outside air (seal windows, instal a high-quality air filter, set HVAC system to recirculation mode, limit use of exhaust fans when not cooking)

  • Have a functioning CO alarm

  • Use a portable air purifier and air conditioning

Granton echoed this advice.

"Most people recommend staying indoors as much as possible and not exercising or doing things outside," he reiterated.

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