Millions of people across North America are facing a growing climate-related health threat as extreme heat and dangerous air pollution occur at the same time, creating conditions that experts warn may put additional pressure on the heart and lungs.
The sudden change in air quality has been especially noticeable in parts of the United States and Canada, where wildfire smoke has turned clear skies into hazy and polluted conditions within hours. Smoke from major wildfires in Canada and Minnesota has spread across several US states, including New York, New Jersey and Wisconsin, while temperatures have risen above 95°F (35°C) in many areas.
Experts said that heatwaves themselves can worsen air pollution. Hot and still air traps pollutants close to the ground and increases ozone formation, while hotter and drier conditions are making wildfires more frequent and severe.
According to the World Health Organization (WHO), heat exposure contributes to hundreds of thousands of deaths worldwide each year, while air pollution is linked to millions of premature deaths annually.
A study published in the American Journal of Respiratory and Critical Care Medicine found that the risk of death rises when people face extreme heat and air pollution together compared with either condition alone.
Fine particles from wildfire smoke can enter deep into the lungs and bloodstream, causing inflammation and worsening conditions such as asthma, heart disease and other chronic illnesses. Extreme heat also places extra strain on the body as it works to control temperature, increasing pressure on the cardiovascular system.
“Both of these environmental stressors are affecting people at the same time,” experts said, adding that dealing with one problem can sometimes make the other more difficult.
Health officials advise people to remain indoors during periods of extreme heat and pollution, keep windows closed, use air conditioners on recirculation mode and run HEPA filters where available.
Scientists call for monitoring temperature, air quality
The scientists said that the future warning systems should monitor both temperature and air quality together to provide better protection for public health.
