Philadelphia gets an F on air quality metrics
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Wildfire smoke seen in Philadelphia in 2023. Photo: Joe Lamberti/AFP via Getty
Philadelphia's air quality is worsening and exposing people to potentially dangerous levels of pollution, per a new report.
Why it matters: Air pollution threatens everyone's health — especially children, older people and people with asthma or heart and lung conditions.
The big picture: 46% of Americans — just over 156 million people — are living in areas with unhealthy levels of ozone or particle pollution, per the American Lung Association's 2025 State of the Air report.
- Meanwhile, the Philly region ranked poorly among U.S. cities for pollution, per the 2021-2023 data.
Zoom in: Philly proper received an F grade for the number of days with high ozone and particle pollution, per the report.
- The city was one of the few areas that received failing grades for ozone smog and particle pollution.
By the numbers: The city had short-term spikes in particle pollution, with an estimated 5.8 unhealthy days per year on average. Last year, Philly received a C.
- Another measure: The Philly region ranked 43rd-worst in the nation for ozone smog.
Threat level: The lung association says that "short-term exposure, such as from peaks or spikes in particle pollution that lasts from hours to days, can kill."
Context: The Philly region, per the report, is vast and includes northeastern Maryland, parts of Pennsylvania's Delaware, Berks and Bucks counties, and South Jersey down to Cape May.
What they're saying: Philly's ranking was particularly impacted by the 2023 wildfire smoke. But even without the worsening effects of wildfires, Philly had failing grades for air quality conditions, Kevin Stewart, director of environmental health at ALA and co-author of the report, tells Axios.
- "We know that as climate change has its influence, it will make these [wildfire] events more likely to occur," he said.
How it works: The report uses local air quality data to grade and rank locations based on ozone pollution, daily particle pollution and annual particle pollution.
Zoom out: California's Los Angeles, Visalia and Bakersfield lead the lung association's new rankings of U.S. metros most affected by ozone pollution.
- Plus: Bakersfield; Fairbanks, Alaska; and Eugene, Oregon, topped the list of those most affected by daily particle pollution.
- Only one continental U.S. metro — Bangor, Maine — showed up on all three of the group's lists of cleanest cities.