Thick smoke descending from Canada and northern Minnesota has triggered poor air quality alerts across the United States. Saturday July 18, there are now 950 active fires in Canada, many beyond control, in Ontario (east), according to new figures from the Canadian Interagency Forest Fire Center (CIFFC).
The fires have so far caused no casualties in Ontario but several isolated villages have been evacuated. If the season has been much less dramatic so far than in 2023, a record year, the virulence of the fires has worsened considerably over the past week.
Chris Carlsten, a professor at the University of British Columbia in Canada, says a growing body of research shows that fine particles from wildfires have a greater impact on the lungs, while vehicle-related pollution affects the heart more. He also notes that paints, plastic and metal can mix with these plumes which gain toxicity as they move due to “photochemical aging”.
Hazardous air quality level
In the states closest to the fires, in the north of the United States, Michigan, Minnesota and Wisconsin, certain areas have recorded air quality levels described as “dangerous” for several days, pushing residents to wear masks when going out. Enveloped in a yellowish fog, Detroit was at the top of the most polluted cities in the world on Friday July 17, according to the specialized site IQAir, not very far ahead of Washington or Chicago. In New York, free distributions took place at train stations and libraries.
“The United States is needlessly invaded by dirty, polluted and harmful air, the quality of which represents a danger, totally unacceptable! », Stormed the American president on Truth Social, announcing that he was going to call the Canadian Prime Minister, Mark Carney.
He threatened to impose new customs duties on Canadian products for “willful negligence,” accusing Canadians of “failing to properly maintain” their forests by not carrying out “basic forest maintenance operations and removal of plant debris,” measures that reduce the risk of fire by limiting available fuel.
Canada and the United States are “in permanent contact,” assured the Canadian Minister of Emergency Management, Eleanor Olszewski, highlighting the “long history of cooperation in the fight against forest fires” between the two countries. Canada has invested $12 billion in the sustainability of its forests and fire prevention since 2020.
A smoky finale?
Pollution worries for the final match between Spain and Argentina, the two finalists of the Football World Cup, in an open-air stadium in New Jersey. Thursday July 16, the silhouette of Manhattan’s skyscrapers was almost invisible and despite an improvement on Friday the smoke could thicken on Saturday before a possible improvement on Sunday, according to the American weather services (NWS).
Organizers are “closely monitoring” the situation, commented Andrew Giuliani, who heads the White House team responsible for organizing the Football World Cup, during a press briefing. The official safety app for fans also encourages them to stay indoors or wear a mask.
Experts and environmental defenders emphasize the link between the multiplication of these episodes and climate change, which favors the lengthening of the fire season due to higher temperatures and a reduction in soil humidity. “Increasingly smoky skies underscore the urgency of a rapid transition to clean energy rather than building new fossil fuel infrastructure,” said Paul Mathewson, director of science programs at Clean Wisconsin.
