Smoke from blazes ravaging western states is counteracting clean air improvements
The northwestern United States has become an air pollution hot spot — literally.
Air quality in states from Nevada to Montana is worse than it was 30 years ago on the days with the most extreme air pollution. Bigger and more frequent wildfires that spew plumes of fine particulate matter into the sky are largely to blame, researchers report July 16 in Proceedings of the National Academy of Sciences.
By contrast, the rest of the country has seen decreasing trends in similar smog and haze over the last three decades. Legislation such as the Clean Air Act, which mandates air quality standards and the regulation of vehicle and factory emissions of particulate matter, is making a difference, says study coauthor Daniel Jaffe, an atmospheric scientist at the University of Washington in Bothell.
But the increase in lung-clogging particulate matter from wildfires shows how the effects of climate