130 million Americans routinely breathe unhealthy air, report finds

Wildfire smoke from Canada caused dangerously unhealthy air quality in New York City and across much of the U.S. in 2023. While air quality has improved greatly in the U.S. in recent decades, wildfire smoke and other climate-influenced problems are endangering that progress. (Ed Jones/AFP via Getty Images)

Over one-third of Americans, or about 130 million people, routinely breathe in unhealthy air, according to the newest State of the Air report from the American Lung Association (ALA). That number is larger in 2023 than in years past, despite significant long-term and ongoing efforts to clean the nation's air. And climate change, the report says, is making the job harder.

Hotter temperatures lead to more ozone formation and can make the air dustier, too. But the biggest climate-fueled pollution challenge comes from wildfire smoke, which has added vast quantities of dangerous fine particle pollution to the air. Western states like California and Colorado have found that wildfire smoke is counterbalancing long-term, successful efforts to clean up pollution from human-controlled industrial sources, like coal-fired power plants and diesel truck exhaust.