A new report shows Pennsylvania communities continue to struggle with poor air quality. Numerous Pennsylvania counties received failing grades for ozone and particle pollution, and the Pittsburgh metropolitan area remains the worst city for short-term and annual particle pollution in the region despite incremental improvements.

On April 24, 2024, the American Lung Association (ALA) released its 25th annual State of the Air report. In this report, the ALA used air quality data obtained from the U.S Environmental Protection Agency’s Air Quality System for two of the most widespread types of air pollution, ozone and particle pollution (also known as smog and soot). ALA analyzes this data to grade counties and rank cities based on ozone, year-round particle pollution, and short-term particle pollution levels. The 2024 report used data over the three-year period from 2020 to 2022. ALA’s annual report allows the public to easily track air quality changes over time and to compare community exposures to air pollution. 

Many Pennsylvania Counties Receive Failing or Poor Grades for High Ozone Days or Particle Pollution

The report shows that many Pennsylvania residents are exposed to harmful levels of air pollution. Based on the air quality data available, the report assigned grades for 36 out of the 67 counties in Pennsylvania for at least one measure of air quality. Bucks and Philadelphia counties both received a failing grade for the number of high ozone days, with Allegheny County receiving a D grade and six other Pennsylvania counties receiving a C grade for high ozone days (Armstrong, Berks, Indiana, Mercer, Montgomery, and Northampton).

For short-term particle pollution, Allegheny and Lancaster counties each received a failing grade. Dauphin County received a D grade for short-term particle pollution and nine other Pennsylvania counties received a C grade (Beaver, Berks, Chester, Cumberland, Delaware, Lebanon, Northampton, Philadelphia, and York).

The grades and rankings for annual particle pollution in the 2024 report were calculated using the new, long-awaited National Ambient Air Quality Standards for fine particle pollution implemented by the EPA earlier this year. The EPA establishes these standards to be protective of public health, including sensitive populations, with an adequate margin of safety using the latest science and health data. The updated annual standard for fine particle pollution is now 9 micrograms per cubic meter, down from the previous standard of 12.

As a result of the report’s use of the updated standard for annual particle pollution, more places around the country earned a failing grade in this year’s report compared to the previous year, including counties in Pennsylvania. Seven Pennsylvania counties, Allegheny, Cambria, Dauphin, Delaware, Lancaster, Philadelphia, and York, all received failed grades for annual particle pollution. Overall, 18 counties in Pennsylvania received a C grade or lower for at least one pollutant measure.

Pittsburgh Metro Area Remains Worst in Region for Particle Pollution

This year’s report once again showed that the cities with the highest levels of short-term particle pollution were those cities in the western U.S. The report identifies wildfires in the western U.S. and Canada as the major contributing factor to the increasing number of days and places with unhealthy levels of particle pollution in recent years. As a result, the 25 cities most polluted by daily particle pollution are all located west of the Mississippi River.

For the first time, the 12-county Pittsburgh-New Castle-Weirton, PA-OH-WV metropolitan area was edged out of the report’s list of the 25 worst cities for daily particle pollution, coming in 26th in this year’s report. The Pittsburgh metropolitan area remained in the top 25 list for worst polluted cities for annual particle pollution, ranking 19th in this year’s report. However, despite incremental improvement in particle pollution levels, the Pittsburgh metropolitan area retains the dubious distinction of being the worst in the Mid-Atlantic region for annual particle pollution and the worst in the country east of Fargo, North Dakota for daily particle pollution levels.

Allegheny County received failing grades for both daily and annual particle pollution under the new EPA standard, despite incremental improvements in particle pollution levels.  Allegheny County saw a slight increase in the annual weighted average of unhealthy air days for ozone smog, earning it a D grade, down from the C grade it received in last year’s report.

The Pittsburgh area’s continued status as the worst in the region for particle pollution and its high ranking nationwide, even without the acute impacts of wildfires experienced by the higher-ranked cities in the West, demonstrates the impact of local pollution sources on our region’s air quality and the need for holding local industrial polluters accountable for particle pollution.

Overall, the 2024 “State of the Air” reports shows that many Pennsylvania residents are still experiencing the harmful effects of air pollution in their daily lives, and that much more needs to be done to ensure communities across the state can breathe clean air.

PennFuture is dedicated to protecting and improving air quality for all of Pennsylvania. If you are interested in supporting our work, please become a member today!