The convergence of extreme heat and poor air quality presents a growing global health challenge, with climate change expected to worsen these interconnected threats. Each year, approximately 489,000 deaths worldwide are attributed to extreme heat, according to the World Health Organization. Concurrently, ambient and household air pollution contribute to an estimated 6.7 million premature deaths annually.
A 2022 study published in the American Journal of Respiratory and Critical Care Medicine indicated that the mortality risk on days experiencing both extreme heat and poor air quality rises by an estimated 21%. Fine particle pollution, often from wildfire smoke, can trigger respiratory distress, including shortness of breath and coughing, and can worsen existing cardiovascular and lung diseases. Extreme heat, meanwhile, intensifies conditions such as cardiovascular disease, diabetes, and asthma.
"We know that many of the impacts of air pollution are through the ways in which it strains our cardiovascular and respiratory systems, and we know that heat also strains our cardiovascular system and our respiratory system," stated Allan Just, an associate professor of public health at Brown University. "When it's hot out, your heart needs to work harder to push blood out to the periphery to try to cool you down, and when it's polluted, the small particles can get from your lungs into your bloodstream, and they cause inflammation, and they can damage your heart tissue."