"The average person in the U.S. has breathed in more harmful wildfire smoke in 2023 than in any year since 2006. This year is part of a trend of increasing fire weather, which fuels the flames and smoke that put health and safety at risk in our warming climate. Fine particle pollution from wildfire smoke is a nationwide health concern. Studies suggest that smoke exposure in the U.S. has increased 27-fold over the last decade. The West has more large fires and local smoke-related pollution, but fires from the western U.S. and Canada affect the entire contiguous U.S. New research links wildfire smoke with stalled or reversed air quality improvements in 30 U.S. states since 2016, with the worst effects in the West. "