Wildfire Smoke Poses Health Risks Across Continents

Wildfire smoke has led to 'very unhealthy' air quality across large parts of the U.S. and Europe, with over 1,083 fires detected in Europe since the start of 2026 Source: Euronews. In the U.S., smoke from wildfires in Ontario, Canada, and northern Minnesota has pushed air quality index (AQI) values above 300 in some areas, a level the EPA considers 'extremely rare' Source: NPR.

Health risks and monitoring

Wildfire smoke contains hazardous pollutants such as PM2.5, which can lodge deep in the lungs, and ultrafine particles (PM0.1) that can enter the bloodstream Source: NPR. Sensitive groups—including children, older adults, and people with heart or lung disease—are most at risk Source: AP News. The EPA maintains an Air Quality Index that classifies levels; anything above 150 is considered unhealthy for everyone Source: AP News. Real-time air quality data is available through EPA maps, PurpleAir sensors, and smartphone weather apps Source: Euronews, AP News.

Protective measures

To reduce exposure, experts recommend staying indoors with windows closed and using air conditioning on recirculate mode Source: Euronews. Wearing an N95, KN95, or KF94 mask when outside can filter out 90-95% of particles Source: Euronews. For indoor air cleaning, upgrading HVAC filters to MERV 13 or higher is advised . A low-cost DIY option is attaching a MERV 13 filter to a box fan with duct tape . Indoor air quality monitors can help track pollution levels .