Regions across US, UK report worsening air quality in new studies

The American Lung Association’s 2025 'State of the Air' report highlights worsening air quality across several U.S. regions, with San Bernardino and Riverside Counties in California ranked as the most polluted due to high ozone and particle pollution levels, increasing risks for respiratory illnesses. The Denver-Aurora-Greeley area in Colorado was ranked sixth worst nationally for ozone pollution, while Austin's Travis County received an 'F' grade for both ozone and particulate matter for the first time since 2019, with experts attributing increased ozone days to rising temperatures and climate change. The Allentown-Bethlehem-East Stroudsburg metro area in Pennsylvania also received a failing grade for daily particle pollution, marking a decline from previous years and highlighting ongoing health risks. Collectively, the report found that nearly half of Americans live in areas with unhealthy ozone or particle pollution, underscoring a national trend of deteriorating air quality and associated health concerns.