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Can face masks help protect you from wildfire smoke? Health expert explains

As wildfires continue to burn in several provinces, smoky skies across parts of the country are prompting recommendations from health officials to wear face masks to avoid inhaling harmful smoke.

Health Minister Jean-Yves Duclos told reporters on Wednesday morning that he was feeling the impacts of the smoky air and encouraged people, especially those with pre-existing respiratory conditions, to wear an N95 mask.

“So, for all of these people, including others that may want to protect themselves against the bad consequences of bad quality air, wearing an N95 mask is the recommended procedure by health authorities," Duclos said on Wednesday.

He noted while wearing a mask is a personal choice, he still recommends Canadians wear one if they're outdoors, as the air quality is among the worst in the world.

“But we also know that these consequences will be worse, as the extent of the bad air quality continues. We are told by firefighters and other health officials that, unfortunately, the situation will continue for a few more days.”


As of Wednesday evening, several major cities across the country are reporting a moderate- to high-risk on the Air Quality Health Index including Vancouver, Edmonton, Saskatoon, Regina, Toronto and Ottawa. What's especially harmful about the current air quality in most regions are the extremely small particles—called fine particulates—that can travel into the lungs when we breathe, explains Joe Fida, CIO of Canadian air purifier company Blade Air.

"It is generally not healthy because it can cause inflammation, swelling—there's a lot of very adverse effects from it and the other problem is that they stay airborne for a very long time," Fida told in a phone interview on Wednesday.

Fida explains these fine particulates, known as PM 2.5, are 2.5 microns in diameter, however, smaller particles can travel further distances and contaminate the air.

"Of course (larger) particulates still travel about 30 to 100 kilometres from the fire but when you look at the fine particulates, they can travel for thousands of kilometres—minutes to hours of airborne travel. But then when you talk about ultra fine particulates, that's several days or weeks they can be airborne and travel; this is what's causing a lot of the pollution downwind of where the fires are occuring."

Dr. Shawn Aaron, respirologist at the Ottawa Hospital Research Institute, told in a phone interview on Wednesday fine particulates that are swirling in the air in high concentrations can enter into a person's lungs and travel into their bloodstream causing the body to react in an inflammatory way.


Everyone can be made vulnerable to the effects of inhaling wood smoke, says Aaron. Instant symptoms of smoke inhalation can include stinging, watery eyes, and excess mucus production in the throat and nose.

For those who breathe in wood smoke for longer periods of time or have a pre-existing respiratory condition like asthma, Dr. Aaron said the body's airway tubes that bring air into the lungs can become swollen and tight, causing issues like coughing, wheezing or shortness of breath.

Additionally, inhaling wood smoke can also trigger an asthma attack in those with a history of lung disease or other chronic respiratory illness.

"The short term impacts of breathing in smoke can actually end up in an asthma or COPD attack where you actually become very short of breath and your airway spasms and you have to see a physician or go to the emergency department," he said.

Aaron adds long-term effects can include blood clots which could lead to angina or heart attacks. Additionally, prolonged exposure to wood smoke can also damage the body's airway cells that break down mucus produced in the lungs and allow the body to properly breathe and clear the lungs. Smoke can "paralyze" these airway cells, allowing the body to clog with mucus and leaving it vulnerable to other infections and bacteria.

"We see increased lung infections and increased risk of pneumonia for days after higher pollution days like today," Aaron said.


By using a face mask when outdoors, specifically an N95 mask, Canadians can reduce their risk of respiratory harms, said Aaron.

N95 masks are used to protect against 95 per cent of particulates which is why they're the recommended face mask, he said, however cloth or paper face masks can provide some mild protection against wildfire smoke.

"You're going to be exposing yourself to a lot fewer of these microscopic dust particles if you're wearing an N95 and that'll be a lot better than if you're wearing your cloth mask or paper mask," Aaron said.

Despite this, he recommends everyone stay indoors and avoid going outside if they can. Aaron says since N95 face masks can protect from fine particulates, they may not be able to fully protect people from volatile gasses being produced by the fires that continuously pollute the air.

For those remaining indoors with the windows and doors shut, additional air filtration can also ensure the indoor air quality remains clean, Fida recommends.

"Even after the pandemic we've seen many countless air threats already in just a few years. Every time you turn around, there's something else threatening our air quality," Fida said.

Having an installed air filtration system like a furnace can be especially useful during high-risk air quality warnings; however portable air purifiers can also be a more affordable option to keep the air in the home purified. Top Stories

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