Bucks County Ranks Second-Worst In PA For Ozone Pollution

Tyler State Park near Schofield Covered Bridge in Newtown Township. Credit: Tom Sofield/NewtownPANow.com

Residents of Bucks County are breathing some of the most ozone-polluted air in Pennsylvania, according to the American Lung Association’s newly released 2025 “State of the Air” report.

The county received a failing grade and is second-worst in the state for high ozone days, trailing only Philadelphia and surpassing Berks County.

The report, which analyzed ozone data from 2021 to 2023 across 35 of Pennsylvania’s 67 counties, paints a concerning picture for the region.

Ground-level ozone, commonly known as smog, is a potent respiratory irritant that can inflict damage akin to a “sunburn of the lungs.” Inhalation can lead to shortness of breath, coughing, and asthma attacks, and has been linked to premature death as well as respiratory, metabolic, and reproductive issues, according to the report.

American Lung Association officials highlighted that warmer temperatures exacerbate ozone formation and slow its dissipation, which is believed to have contributed to the elevated levels in the data.

The report also offers a glimmer of hope, because there has been a significant improvement in Bucks County’s ozone levels compared to the late 1990s and early 2000s.

The air quality situation varies across the region.

Neighboring Montgomery County received a “C” grade in the report, while just across the state line, Hunterdon County in New Jersey earned a “D” and Mercer County, New Jersey, also received a failing “F.”

Bucks County’s data did not include information on particle pollution.

A 2023 report by the Bucks County Herald shed light on a potential factor contributing to the county’s poor ozone data. Bucks County has only one ozone monitoring site, located in the densely populated and industrialized area of Bristol, which also has a number of highways and is not far from the Philadelphia city line.

In contrast, neighboring Montgomery County operates three monitoring stations, including sites in less populated areas.

The “State of the Air” report reveals a broader national trend of worsening air quality.

The report found that nearly half of the U.S. population is now breathing unhealthy levels of air pollution. The group found that 156 million people live in areas receiving an “F” grade for either ozone or particle pollution, an increase of 25 million compared to last year.

Extreme heat and wildfires were cited as contributing factors to the deteriorating air quality across the nation.

“Air pollution is causing kids to have asthma attacks, making people who work outdoors sick, and leading to low birth weight in babies,” stated Harold Wimmer, president and CEO of the American Lung Association. “This year’s report shows the dramatic impact that air pollution has on a growing number of people. Even as more people are breathing unhealthy air, the federal staff, programs and policies that are supposed to be cleaning up pollution are facing rollbacks, restructuring and funding challenges.”

The report also listed the top 10 most and least ozone-polluted cities in the nation. California dominated the most polluted list, with Los Angeles-Long Beach, CA, taking the top spot. In contrast, Augusta-Richmond County, GA-SC, was named the least polluted city for ozone.

Top 10 Cities Most Polluted by Ozone Pollution: