Wildfire smoke is eerie on the landscape when, like fog, it makes distant buildings disappear before your eyes. But it’s also potentially lethal, especially for those with pre-existing conditions such as diabetes, heart disease and pulmonary disease.
“Those are some of the things that can make people more susceptible to wildfire smoke, and exposure to wildfire smoke can worsen the symptoms of those conditions, or trigger some of the risks or more acute effects,” says Angela Yao, senior scientist at the BC Centre for Disease Control (BCCDC). “That’s primarily why seniors may be more concerned about their exposure.”
In addition, the Canadian Ophthalmological Society has issued a warning, urging people to be mindful of their eyes as wildfires burn across the Prairies and the resulting smoke travels across the country. Frontline workers are particularly susceptible, but even those thousands of kilometres away can be affected. In the latter case, the smoke’s effect will likely be irritation or it will feel like an allergen, causing red, irritated or burning eyes. If people feel those effects, they should consider staying inside and using air purifiers, the eye doctors advised. Preservative-free artificial tears can also help. Contact lens-wearers, meanwhile, should be sure to take their lenses out every day — an advisable practice anyway, but one some fail to follow — and clean them with certified contact-lens solution.
Yao says the best way to protect oneself overall is to limit exposure to wildfire smoke, and the most effective way to do that is to find cleaner indoor air.
“So [the best advice] would be to stay indoors with your air cleaners operating,” Yao says, adding that that can either be a filtration system that's built into your building, and if that doesn’t exist, a portable HEPA air cleaner, or even do-it-yourself (DIY) air cleaners that you can make with a box fan and furnace filters. “We actually have a fact sheet on how to make these DIY air cleaners on our website. They can be quite effective, especially if they’re properly constructed and used in a small room with doors and windows closed.”
That said, Yao says if you have the budget, the air purifiers one buys are usually a better option, and they tend to come with an air-quality indicator, which is helpful for knowing whether the air filtration is working.
“There are some additional functions that come with the commercial ones,” she says, adding that in general, we should all be monitoring our symptoms, especially when we’re outdoors. “Be cautious and listen to your body.”
Yao says the Air Quality Health Index (AQHI) is a good place to start when contemplating going outside for a physical activity — something we all embrace as the weather turns warm, which, unfortunately, coincides with wildfire season. She says it’s particularly effective in urban centres.
“In some areas, you may be very far away from the actual air quality monitor, so the reading that gets reported may not really reflect your local conditions,” she says of more rural areas. “Smoke can be quite transient or sporadic, so the AQHI is a tool, [and yet,] different people can respond differently, so you want to adjust your [behaviour] according to your own condition.”
As such, Yao recommends common sense.
“I think it’s a bit of self-calibration,” she says. “Some people may have less tolerance. You really have to monitor the situation — monitor the forecast, monitor the air quality in your region, adjust your activities, especially if you're planning outdoor activities. [You should] really think about the intensity and the length of the activity. And then seek cleaner indoor air as a way to reduce your exposure and mitigate the impact.”
Smoke, she says, is a very complex mixture of particles and gas and PM 2.5, also known as fine particles, are the ones that we know have the most impact and are therefore the ones that are most commonly measured.
“Because they’re so small, they can get really deep into the lungs and cause all kinds of inflammation and a range of responses in our body,” she says.
Symptoms to watch for
Wildfire smoke can make it harder for your lungs to get oxygen into your blood and can irritate your respiratory system and cause an immune response, which may lead to inflammation that affects other parts of your body.
Common symptoms, usually managed without medical attention, include: eye irritation, runny nose, sore throat, mild cough, phlegm production, wheezy breathing or headaches.
More severe symptoms, for which you should seek immediate medical attention, include:
- shortness of breath
- severe cough
- dizziness
- chest pain
- heart palpitations
Smoky air may also increase the risk of some infections, including:
- pneumonia
- COVID-19
- ear infections (in children)
Source: BCCDC