A recent report by the American Lung Association (ALA) has highlighted a concerning trend in air quality across the United States, with California cities prominently featured among the most polluted. The ‘State of the Air’ 2025 report reveals that approximately 156 million Americans—nearly half the nation’s population—are exposed to unhealthy air, primarily due to increasing wildfire smoke, despite reductions in emissions from vehicles and factories.
The ALA’s assessment, covering data from 2021 to 2023, examined ground-level ozone (smog), year-round particle pollution, and short-term spikes in particle pollution. Bakersfield-Delano, California, emerged as the city with the most severe persistent particle contamination. Visalia and Fresno-Hanford-Corcoran, also in California’s Central Valley, secured the second and third spots, respectively. Other California cities such as Los Angeles-Long Beach and San Jose-San Francisco-Oakland also featured prominently on the list.
Beyond California, cities like Eugene-Springfield, Oregon; Detroit-Warren-Ann Arbor, Michigan; and Houston-Pasadena, Texas, were identified as areas with significant air quality challenges. The report underscores that while industrial and vehicular emissions have declined, the increasing frequency and intensity of wildfires have become a dominant source of air pollution, particularly in western states.
Harold Wimmer, President and CEO of the ALA, emphasized the growing impact of air pollution on public health, stating, “This year’s report shows the dramatic impact that air pollution has on a growing number of people.” He also expressed concern over the challenges faced by federal programs tasked with mitigating pollution, noting issues such as rollbacks, restructuring, and funding constraints.
The report’s findings highlight the multifaceted nature of air pollution, influenced by factors including population density, geography, and weather patterns. As wildfires become more prevalent and severe, they contribute significantly to the deterioration of air quality, posing heightened risks to public health.
In light of these findings, the ALA advocates for strengthened environmental policies and increased funding for programs aimed at improving air quality. The organization also calls for heightened public awareness and community engagement to address the escalating challenges posed by air pollution across the United States.
