Nearly half of the US population is now living in areas with unhealthy air, according to a new report, with California emerging as one of the worst-affected regions. The 2026 “State of the Air” report by the American Lung Association says about 152 million people, or around 44 percent of Americans, are exposed to dangerous levels of air pollution. That includes more than 33 million children. In California, the situation is even worse. Around 82 percent of residents of this state live in counties where air quality levels are considered unhealthy. In fact, the Los Angeles-Long Beach area was once again ranked the most ozone-polluted metro region in the country. It has been given this title 26 times in 27 years. The report found that on average,
the region saw more than 150 days with unhealthy ozone levels. It was also found to be the worst region in the country for both short-term and year-round particle pollution. Ozone pollution, also called smog, is formed when emissions from vehicles and other sources react in heat and sunlight. It may irritate the lungs, making breathing difficult. Particle pollution includes particle matter (PM2.5), which originates from vehicle emissions, industrial activities, and forest fires. PM2.5 is small enough to penetrate into our blood and causes health issues such as asthma, heart disease, and lung cancer. Cities in Southern California, including Los Angeles, Riverside, and San Bernardino, failed in various tests for pollutants. While the report does note some improvement in certain areas — including lower levels of annual particle pollution in Los Angeles — it notes worsening ozone levels compared to last year. Experts say the problem is largely because of emissions coming from vehicles and industries, and is made worse by weather patterns that trap pollution in the region. Another issue identified by the report is the potential harm that may be caused by recent changes to US federal policy, especially due to loosening of air quality guidelines that could result in thousands of premature deaths in the future. It is important to note that children are particularly susceptible to air pollution, since their lungs are not yet fully developed and they inhale more air compared to their body mass. The results demonstrate that air pollution is prevalent in the US, although some areas are experiencing steady improvements.
