A new report from the American Lung Association revealed that two counties in the Inland Empire are the worst in the nation for ozone air pollution, failing all federal safety standards.
At a city level, the Los Angeles and Long Beach metropolitan areas were also ranked worst for ozone pollution.
New federal EPA rollbacks are expected to make the pollution even worse.
While there’s much to love about the Inland Empire, there’s also something that many people overlook because it’s often invisible. And that’s what roughly 4.6 million people there are breathing in every day: air pollution.
Smog is pictured among power lines in Southern California in an undated file photo. (KTLA)
The State of the Air Report for 2026 named Riverside and San Bernardino the most polluted for ozone — also known as smog. Los Angeles County was ranked third.
Most Polluted Counties:
1. San Bernardino County, CA
2. Riverside County, CA
3. Los Angeles County, CA
4. Tulare County, CA
5. Kern County, CA
6. Maricopa County, AZ
7. Fresno County, CA
8. Harris County, TX
Chelsea Grosso was born and raised in the Inland Empire and is now raising her family there. “My daughter has asthma, so you think back and, I mean, is this something that’s exacerbating her asthma, making it worse?” she asked.
With poor air quality comes a higher risk of health issues.
“People are more at risk due to the effects of ozone, which is a corrosive gas that can have a real impact on your breathing, your airways, and your lungs,” said American Lung Association Assistant VP for Nationwide Clean Air Policy Will Barrett.
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Barrett said a mix of certain pollutants, especially on hot and sunny days, is the perfect recipe for this hazardous gas formation.
The biggest culprit is the transportation sector, which reportedly makes up about 80 percent of ozone pollution.
“You think about the tens of thousands of truck trips every day coming up and down, into and out of the warehouses,” he said.
The Inland Empire’s massive logistics industry, millions of cars on the roads, and also extreme heat, drought and wildfires can all have an impact on air quality.
Interestingly enough, data centers are an emerging source of air pollution as well. Experts say the resources to support these centers for A.I. is astounding.
Barrett said solutions start with policymaking.
Despite the federal government rolling back certain clean air protections, he said state and local Air District policies for cleaner air are crucial.
Grosso said, “I would like for maybe some advice and whatever advice they give us, we’ll follow.”
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