Pervasive wildfires create serious risks even for those far away

Environmental scientists have been warning for years that climate change would cause Canada’s wildfires to grow in size and frequency.

But Canada’s record-breaking 2023 fire season that generated days of dangerous smoke-filled skies for the country, New York and parts of the eastern United States has sparked concerns that those predictions may be coming sooner than anticipated.

“What was historically characterized as an extreme event will become more common,” said Andrew Vander Yacht, an associate professor of forest and fire ecology at SUNY ESF. “But what will also happen is we’ll get more novel events, things that we’ve never seen before.”

That was the case in 2023 when Canada’s wildfire season that starts in May took off at a remarkable rate.

By June 10, Canadian wildfires had scorched 4.5 million hectares of land – eclipsing the previous full annual record set in 2014. Wildfires would go on to burn more than 17 million hectares lost by year’s end.

Impacts from this unparalleled season weren’t strictly confined to the fire’s origins in Canada. In early June, fires in the Quebec province generated smoke that traveled thousands of miles south into New York, the eastern half of the United States and beyond.

Cities were submerged in yellowish hazy skies and air quality alerts were issued advising residents to limit their exposure and prolonged inhalation because of health risks.

The EPA’s Air Quality Index (AQI) tracks pollution, smog and smoke particles on a scale up to 500. Readings of 100 or higher are considered unhealthy for those with health issues; 150 or higher unhealthy for more of the general public; and 200 or higher unhealthy for nearly everyone.

On June 8, Syracuse registered 108 on the AQI scale, 162 in Albany and as much as 178 in New York City — the worst single-day rating since June 2006.

“The short-term health problems from inhalation of smoke particles can be respiratory effects, eye irritation, congestion, headache, cough and chest tightness,” says Gillian Mittelstaedt, an air quality and health professional, “but that’s just the beginning of a whole cascade of effects.”

Studies have calculated that wildfire smoke causes up to a 10% increase in respiratory-related hospitalizations, while other pollutants only account for a 1% increase.

The particulates within wildfire smoke are measured to be 2.5 microns and smaller — or 30 times smaller than a strand of hair. These ultra-fine particles bypass the body’s natural forms of filtration, and the chemical fingerprint of wildfire smoke has been found in every single organ in the body.

Exposure to heightened levels for just a few hours or weeks can precipitate asthma episodes, heart attacks and premature mortality. Prolonged exposure, over months or years, can significantly reduce life expectancy, according to Marshall Burke an associate professor in the Stanford Doerr School of Sustainability.

Wildfire smoke that has traveled significant distances over several days like what occurred in June 2023 can pose an even more serious threat to those who inhale it. As smoke moves further from the source, other atmospheric pollutants get caught in it, making the noxious cloud significantly more harmful.

Among the factors that made Canada’s fire season so destructive is aggressive fire prevention efforts over the past decade that created a denser forest landscape with less tree diversity.

Historically, repeated-but-minimal fires served as a natural form of control in which fires would naturally put themselves out. Playing this out over a landscape, a mosaic of burned trees and fresh growth dot the forest such that subsequent fires don’t expand too far.

“If you’re burning at a high frequency but low intensity, you’re reducing the amount of fuel so that subsequent fires are burning through a force structure and a pattern in which the fuels are arranged,” Yacht explained. “Putting out all these fires has led to an accumulation of fuel.”

As wildfires intensify in the coming years, residents on both sides of the U.S.-Canada border should expect to grapple with more frequent air quality warnings and the negative health effects that come with smoke inhalation.

Aside from societal policy change and stricter guidelines regarding greenhouse emissions to curb climate change, the next course of action is to adapt to the new norm of persistent smoke days.

While wearing a properly fitted N-95 mask on days with poor air quality is typically recommended, Mittelstaedt suggested utilizing air purifiers on a high setting that can filter out a significant amount of smoke particles in the right indoor spaces.

“We’re not going to wear masks inside but that’s where we’re getting a lot of our exposure,” Mittelstaedt said. “We spend 22 hours a day inside a structure so air filtration is vitally important.”

Mittelstaedt added that people who don’t take steps to limit their exposure to wildfire smoke should consider how it may be affecting their health.

“People need to understand what the risk is, know that the risk exists, that the risk applies to them,” she said. “Then they need to have the belief that they can take action.”