Canada’s Record Wildfires Made Four North American Cities Among the Five Most Polluted Cities in the World

Hundreds of wildfires have been burning in nearly all of Canada’s provinces for almost a month, the smoke from them drifting down into the midwestern and eastern United States.

Major U.S. cities from Minneapolis to Charlotte have been affected by the eerie orange-tinged wildfire smoke, but last week four out of the five most polluted cities in the world — New York, Toronto, Montréal and Washington, DC — were in North America, according to Swiss technology company IQAir.

“This is not something that we’re talking about future generations dealing with,” said New York Governor Kathy Hochul during a press conference last week, as CNBC reported. “We are truly the first generation to feel the real effects of climate change.”

 The smoke from the Canadian wildfires contains particulate matter, one of the most dangerous types of air pollution.

“Wildfire smoke is made up of many elements such as gases and water vapor, but the chief among them is particulate matter (PM), including PM2.5 – particulates measuring 2.5 micrometers in diameter or less – and ultrafine particles (UFPs). Airborne particulate pollutants are the primary health hazard found in smoke,” IQAir said last month. “UFPs – particulate matter smaller than .01 micron in diameter – is the most dangerous airborne pollutant due to its small size. When inhaled, UFPs easily cross over from the lungs into the bloodstream and all other regions of the body.”

This year is the worst wildfire season Canada has ever experienced in terms of area affected, with more than 20 million acres having been burned across the country, reported BBC News. That’s 21 times more than the average over the past 10 years.

Abnormally warm and dry conditions are expected to last through the summer, creating a continued high wildfire risk across the country.

“Climate change is increasing the frequency and intensity of wildland fires and creating longer fire seasons in Canada,” said Michael Norton, director general of the Northern Forestry Centre at Natural Resources Canada, as BBC News reported.

Since there are so many fires burning at once, firefighters must prioritize which to fight and which to let burn, reported CNN.

“You protect people, infrastructure, watersheds, so there’s a prioritization system,” Canadian wildland fire ecologist Robert Gray told CNN. “If you’ve got these fires that are burning way out in the back forty, and they’re not threatening anything immediately, then you’re going to have to let them do their thing.”

Canadian resources to fight wildfires have been short, so at least 10 other countries have stepped up to deploy their firefighters, including Mexico, Chile, Costa Rica, New Zealand, South Korea, Australia, South Africa, France, Spain and the U.S.

“International groups keep saying, you need to shift the focus to upfront mitigation and prevention so you’re spending less money on response and recovery,” Gray said. “It’s ridiculous. We spend billions of dollars once the fire breaks out, but we don’t invest the money upfront to mitigate the fires from happening in the first place.”