How to stay safe amid the smoke and poor air quality of wildfire season

As more than 200 wildfires continue to burn in British Columbia, experts are advising residents to start preparing for wildfire smoke and poor air quality.

Air quality warnings are already in place for most of B.C.'s southern Interior, and fire risk in the province is very high.

The warnings come after a record-breaking heat wave elevated the wildfire risks far beyond normal for most of Western Canada.

Naomi Zimmerman, assistant professor of mechanical engineering at the University of B.C., says residents shouldn't wait for an air quality warning to start getting prepared for smoky skies.

"When we have wildfire periods, we can see concentrations of particulate matter ... in the range of over 50 to hundreds of micrograms per cubic metre, whereas typically we might see, say, less than 10 micrograms per cubic metre on a given day in Vancouver," she said. "It's quite a substantial increase."

Poor air quality and smoky conditions are particularly concerning for vulnerable populations, according to Zimmerman.

This includes pregnant people, older people, young children and people with pre-existing conditions like asthma or other respiratory illnesses.

"It's not likely something that you're going to see potentially as an acute health impact," she said. "It's more so that ongoing exposure to these smoke events puts you at higher risk of developing some of these conditions [like asthma]."

How to deal with wildfire smoke and poor air conditions

Zimmerman has some advice for how to deal with poor air quality within your house:

• Keep windows closed as much as possible during wildfire episodes.
• Limit your time outdoors and avoid exercise when there are air quality advisories in place.
• If you have to go outdoors, wear a face mask.
• Avoid smoking or lighting candles indoors.
• When cooking, switch on an exhaust fan.
• If you are driving in smoky conditions, switch on the recirculation mode on your car A/C and ensure your filters are up to date.
• Purchase an air purifier or filter for your house.

Zimmerman says you should look for HEPA-rated air purifiers when buying one for your home.

She notes that air purifiers come with ratings that vary depending on the size of the room for which they're intended.

"Maybe you need a bigger one for your open living room and a smaller one for your bedroom," she said. 

Zimmerman also notes that purifiers often indicate when the filter within them needs to be replaced. Keep replacement filters on hand.

If you are unable to purchase an air purifier, Zimmerman recommends attempting to build your own using a box fan and a furnace filter.

As for face masks, Zimmerman says N95 masks are the best for outdoor activity during smoky conditions, as long as they are fitted correctly. 

Even regular cloth masks offer some level of protection, she says.

"Same considerations apply when you think about the pandemic versus wildfire smoke — the fit is important," she said. "If you're breathing through a mask, the amount of pure smoky air that you're going to be breathing is going to be reduced."

Zimmerman is working on research about smoke infiltration within buildings and says retrofitting air filtration systems within buildings will be "a consideration going forward."

How to keep pets and plants safe

While smoky conditions certainly affect vulnerable humans and those who have to be outdoors, they will also affect pets and trees.

The B.C. SPCA says that while smoke tends to collect higher in the air, sparing most animals, there are still concerns for certain breeds of dogs.

"One example includes dogs that are brachycephalic — these are dogs with shorter faces," said B.C. SPCA spokesperson Lorie Chortyk. This includes pugs, bulldogs and shih tzus.

"Brachycephalic dogs are already at risk for respiratory complications, so anything that could compromise their breathing could be a serious concern."

If you have to walk your pet during smoky conditions, it is best to go when the sun isn't high in the sky, said Chortyk. This would mean walking your pet either early in the morning or late in the evening.

"Animals should always have access to fresh, potable water and plenty of shade, especially if they tend to spend much of their time outside," she said.

If a pet starts to exhibit unusual behaviour, the SPCA advises calling a veterinarian.

Urban forests and trees, which are drying out as a result of B.C.'s heat wave, take in airborne pollutants like carbon dioxide, according to Joe McLeod, city arborist and supervisor of urban forests for Vancouver.

He says the ongoing heat wave is affecting trees more than particulate matter from wildfire smoke.

However, residents should still try to water dry trees and plants to ensure they continue to survive the coming months, he said.

"We do encourage residents, obviously, not to have open flames in parks and not to be smoking in parks," he said. "Just so we don't have a situation where any of our park assets have a fire."