California Clean Air Progress at Risk: Lung Association “State of the Air” Highlights Local Pollution Progress and Challenges

Today, the American Lung Association released its 27th annual “State of the Air” report, which finds that nearly half of the children in the U.S. are breathing unhealthy levels of air pollution, including 7 million kids in California. Los Angeles-Long Beach was once again ranked as the most ozone-polluted city in the nation; Bakersfield ranked as the most polluted for annual particle pollution despite ongoing improvement shown in the 2026 report.

“Clean air is essential to the health and wellbeing of families across California. Children deserve to breathe air that won’t make them sick,” said Will Barrett, assistant vice president, nationwide policy, clean air for the American Lung Association. “Despite decades of progress, too many people throughout California are living with unhealthy levels of air pollution, and the risk to clean air progress is only growing. Air pollution in California is causing kids to have asthma attacks, contributing to chronic health conditions, and making people who work outdoors sick.”

Barrett added: ““State of the Air” shows that cleaning the air in California has been a hard-fought effort for decades, and we can’t let that progress stall. The federal government has taken direct aim at California’s clean air programs within its broader effort to strip healthy air protections. California policymakers must resolve to defend lung health, including making strong budget investments in clean transportation, advancing statewide rules to clean up diesel hotspots like warehouses and shifting transportation funding toward healthier transit, walk and bike options rather than ongoing highway expansion. We need our leaders to step up at home while we call on everyone to tell EPA that our kids’ health counts.”

The Lung Association’s “State of the Air” report grades counties’ air quality in terms of unhealthy levels of ground-level ozone pollution (also known as smog), and year-round and short-term spikes in particle pollution (also known as soot) over a three-year period (2022-2024). The report also ranks counties and metropolitan areas in cleanest and most polluted lists for each pollutant. Both ozone and particle pollution can cause premature death and other serious health effects such as asthma attacks, heart attacks and strokes, preterm births and impaired cognitive functioning later in life. Particle pollution can also cause lung cancer.

Infants, children and teens as a group are more susceptible to the health impacts of air pollution. Their lungs are still developing; they breathe more air for their body size than adults and they are frequently exposed to outdoor air. Air pollution exposure in childhood can cause long-term harm, including reduced lung growth, new asthma cases and increased risk of respiratory diseases.

Notable California findings from the “State of the Air” 2026 report:

Progress lands California communities among cleanest cities lists:
Four California cities appeared on at least one of the lists for cleanest cities in America, including:

• Salinas, cleanest cities list for ozone and ranked 23rd best for annual particle levels.
• Chico, cleanest cities list for ozone (zero unhealthy days reported in “State of the Air” 2026).
• Santa Maria-Santa Barbara, cleanest cities list for short-term particles (zero unhealthy days). 
• San Luis Obispo-Paso Robles, cleanest cities list for short-term particles (zero unhealthy days).

Many California cities posted their best ever reports, highlighting decades of improvements:

• Seven communities achieved their lowest annual particle pollution levels: Bakersfield, Chico, Los Angeles, Fresno, Sacramento, The San Francisco Bay Area and San Luis Obispo each saw their lowest annual particle pollution levels.
• Five communities experienced their fewest ever number of unhealthy particle days: Bakersfield, Chico, Fresno, the San Francisco Bay Area and San Luis Obispo all posted their cleanest ever reports for short-term particles. 
• Two communities experienced their fewest unhealthy ozone days: Sacramento and Redding each saw their fewest ozone days over the history of the ”State of the Air” report.

Despite progress, California cities continue to dominate most polluted lists: 

• Annual particle pollution: Seven California cities rank among the worst for annual particle levels: Bakersfield (ranked most polluted US city); Fresno (4th most polluted); San Diego and Visalia (tied for 5th); Los Angeles-Long Beach (7th): San Francisco Bay Area (13th); El Centro (21st).
• Unhealthy particle pollution days: Six cities rank among the most polluted for short-term particle pollution days, including: Bakersfield (ranked 3rd in the US with 26.2 days); Visalia (5th, 19 days); Fresno (6th, 16.5 days); Los Angeles-Long Beach (7th, 13 days); El Centro (14th, 9.2 days); San Francisco Bay Area (20th, 7.3 days). 
• Unhealthy ozone pollution days: Eight California cities appear among the most polluted for ozone, including: Los Angeles-Long Beach (ranked most polluted US city with 159.2 days annually); Visalia (2nd, 92.7 days); Bakersfield (3rd, 75 days); Fresno (5th, 54.5 days); San Diego (7th, 37.8 days); El Centro (10th, 26.8 days); San Francisco Bay Area (14th, 20.2 days); and Sacramento (16th, 16.7 days).

Nationally, the report found that 33.5 million children in the U.S., or 46% of people under 18 years old, live in an area that received a failing grade for at least one measure of air pollution. In total, 44% of people of all ages in the U.S. (152 million people in total) live in a county that received a failing grade for at least one measure of air pollution. 32.9 million people live in counties with failing grades for all three measures. In California, more than eight in ten (82%) people live in counties affected by unhealthy air. 

The Lung Association is calling on everyone to urge US EPA to value the health of America’s kids. Historically, EPA has played an essential role in protecting people’s health from air pollution. The current EPA has retreated from its public health foundation by rolling back clean air protections. This EPA has also taken the recent step of eliminating health-related information from its economic analyses, meaning that the costs of pollution to kids, families and communities will not be counted as policies are undone. EPA must not devalue kids’ health.

See the full report results and take action at Lung.org/sota.