The Philadelphia region has finally dropped off the list of the 25 worst metro areas for ozone smog. But the American Lung Association’s State of the Air report shows that the levels of air pollution are still worrisome. Sophia Schmidt hacked through the data for The Philadelphia Tribune.

The report looked at both ozone and fine particulates air pollution and compared multi-year averages dating back to the 1990s to data from 2018–2020.

In the latter period, the Philadelphia-Reading-Camden metro area averaged less than seven unhealthy high-ozone days per year, the fewest in at least two decades.

Despite the improvements, the report awarded the Philadelphia region area a “failing” grade for ozone pollution.

“It’s improved to the best ever for ozone smog,” said Kevin Stewart, director of environmental health at the American Lung Association of the Mid-Atlantic. “It’s not on the worst 25 cities list anymore, but it still gets a substantial ‘F.’”

The reason is particulate pollution, where the metro made little progress.

Among individual counties, Delaware County was the most polluted as measured by particulates, while Philadelphia and Bucks counties tied for worst ozone pollution.

Read more about air pollution in The Philadelphia Tribune.