Wildfire Smoke From Canada Poses Health Risks Nationwide
WHO:
Fast Company - Jennifer Stowell, a research scientist at Boston University’s Center for Climate and Health.
Fast Company - Mary Maldarelli, a fellow in pulmonary and critical care at the University of Maryland Medical Center.
WHAT:
Fast Company - More than 850 wildfires are currently burning in Canada.
Fast Company - Smoke from Canadian wildfires is expected to reach Europe next week.
Fast Company - Tiny particles of smoke called PM 2.5 can enter lungs and bloodstream, leading to reduced lung function and increased risk of heart attack and stroke.
Fast Company - A study showed an 18% increase in medical visits for heart and lung issues in Baltimore due to Canadian wildfire smoke.
Fast Company - In California’s Bay Area in 2020, there was a 43% increase in strokes and other cardiovascular issues due to wildfire smoke.
Fast Company - A 2025 study indicated that the risk of health effects from wildfire smoke lasted at least three months after exposure.
Fast Company - Smoke can react with urban pollution to create more ground-level ozone, exacerbating asthma and other health issues.
Fast Company - Smoke samples were found to be twice as toxic five hours after release from a fire and four times as toxic after more time.
Fast Company - The area burned by wildfires in Canada each year is now roughly double what it was in the 1970s.
Fast Company - A record area, the size of England, burned in Canada in 2023, with another 5.3 million hectares burned in 2024.
WHERE:
Fast Company - Smoke is reaching cities from Chicago to New York City.
Fast Company - The area burned in Canada is now roughly double what it was in the 1970s.
WHEN:
Fast Company - A study in Baltimore looked at the effects of Canadian wildfire smoke in 2023.
Fast Company - In California, the increase in strokes and cardiovascular issues was noted in 2020.
Fast Company - A study conducted in Montana observed residents over the next two years after a fire caused six weeks of smoky air.
Fast Company - A 2025 study showed lasting health risks from wildfire smoke exposure.
WHY:
Fast Company - Climate change is making wildfires larger and more likely, leading to increased smoke exposure.
HOW:
Fast Company - Residents are advised to track local air quality indices and limit outdoor activities when the air quality index exceeds 150.
Fast Company - Recommendations include using air conditioning set to recirculate air and having air filters and N95 masks available.
(UPDATED July 17, 2026 13:31 UTC)
More than 850 wildfires are currently burning in Canada, and smoke from these fires is expected to reach cities from Chicago to New York City next week. Research indicates that tiny particles from the smoke can enter the lungs and bloodstream, leading to serious health issues, with a study showing an 18% increase in medical visits for heart and lung problems in Baltimore due to this smoke. Experts recommend that residents monitor local air quality indices and limit outdoor activities when the index exceeds 150, while also using air conditioning set to recirculate and having air filters and N95 masks on hand.