San Diego air quality gets failing grades
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San Diego County is one of the most polluted places to live in America, according to an annual American Lung Association report released today.
Why it matters: Local residents face an elevated risk of health conditions linked to air pollution, from wheezing and coughing to premature death.
- Air pollution threatens everyone's health, but especially the hundreds of thousands of children, seniors and people with asthma or heart and lung conditions living here.
Driving the news: San Diego County earned failing grades on key air quality metrics in the 2026 State of the Air report by the ALA.
- The ozone and particle pollution in the metro area and county ranked among the top 10 worst in the country.
- San Diego jumped from 59th worst to 5th worst for year-round particle pollution among U.S. metros in this year's report.
Between the lines: The polluted Tijuana River is releasing toxic gas that's fueling local air pollution, and has been worsening air quality throughout the region for years.
- San Diego scientists revealed many residents are being exposed to high levels of hydrogen sulfide, validating complaints of strong rotten egg, sewage smells and respiratory health issues in South Bay communities.
- Extreme heat, drought and wildfires are also contributing to unhealthy levels of air pollution nationwide, per the report.
The big picture: About 44% of Americans, or 152 million people, are living in counties that received failing grades for unhealthy levels of ozone or particle pollution, per the report.
- California cities dominate the most-polluted lists, despite several seeing declining pollution levels.
- In California, more than eight in 10 (82%) people live in counties affected by unhealthy air, and more than seven million children are breathing unhealthy levels of air pollution, per the report.
How it works: The report used local air quality data to grade and rank locations in the categories of ozone pollution, daily particle pollution and annual particle pollution.
- It includes data from 2022-2024, "the most recent three years of quality-assured nationwide air pollution data publicly available."
- Ozone is a gas that, at ground level, is a harmful irritant. Particle pollution involves tiny airborne particles from wildfires, fossil fuel burning and more.
State of play: The ALA found that ozone pollution worsened across much of the U.S. over the past two years after a run of successful reductions, Axios' Justin Mack reports.
- The report warns that recent EPA rollbacks, such as the repeal of the 2009 Endangerment Finding in February and the weakening of power plant and vehicle emission standards, threaten to reverse decades of air quality gains.
- There's a growing risk to local progress as the federal government has targeted California's clean air programs, according to Will Barrett, the ALA's assistant vice president for nationwide clean air policy.
- Policymakers need to invest in clean transportation and shift funding toward transit, walk and bike options instead of highway expansion, he said in a statement.
What you can do: Check daily air pollution forecasts at Airnow.gov, and reduce emissions by driving less and using less energy at home.