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Pittsburgh metro area again makes Worst 25 in U.S. lists for Fine Particle Pollution; Ozone levels improve for third year to best ever, but still fail standard, finds 2018 State of the Air report

Editors Note: Updated Trend Charts and rankings for metropolitan areas and county grades are available at on April 18, 2018 at 12:01 a.m. EDT.

(April 18, 2018) - Pittsburgh, PA

The American Lung Association’s 2018 “State of the Air” report found that air quality in the Pittsburgh-New Castle-Weirton, PA-OH-WV metro area remained poor for ground level ozone; and because of results for fine particle pollution, Allegheny County placed the metro area among the worst ten in the nation. 


The “State of the Air” report gives results for three measures of air pollution—days with elevated ozone, and daily and annual values for fine particle pollution. Outside of California, Allegheny County is the only county in the United States that recorded failing grades for all three.  


For ozone, the 3-state, 12-county metro area showed general improvement, posting its best outcome for the third consecutive report, but in Allegheny County alone, the levels were frequently high enough that the metro area still ranked 32nd worst out of 227 across the country.  In Pennsylvania, the metro area ranked second worst after Philadelphia.


For fine particle pollution, the metro area’s rank worsened for the daily measure from 17th worst in the country to 10th worst out of 201, with Allegheny County’s frequency of unhealthy days for this pollutant not only showing the only increase in Pennsylvania, but also worsening enough to come in as the highest for any county east of Utah.  For the annual measure, the average increased from last year’s best-ever result, but the metro area’s rank held at 8th worst (of 187 this year) for the third report in a row. The metro area is tied with the Lancaster, Pa., area for the worst in the country east of California.


Compared to the 2017 report, the Pittsburgh-New Castle-Weirton metro area has seen a general decrease in unhealthy days for ozone. This is despite a trend seen in most U.S. cities toward higher ozone pollution levels. In contrast, the upticks in the particle pollution results for Allegheny County end the steady decade-long improvement for both particle pollution measures beginning with the 2008 “State of the Air” report.


“The 2018 ‘State of the Air’ report finds that unhealthful levels of ozone and fine particle pollution in the Pittsburgh metro area put our citizens at risk for premature death and other serious health effects such as asthma attacks and greater difficulty breathing for those living with a lung disease such as COPD. High levels of year-round particle pollution mean our citizens also face an increased risk for lung cancer.  Daily spikes of particle pollution are dangerous and can even be lethal for people with lung and heart disease.  As long as there are many days with high ozone levels, people with lung diseases such as asthma will continue to need medical attention,” said Kevin Stewart, Director of Environmental Health, American Lung Association of the Mid-Atlantic. “Across the nation, the report found continued improvement in air quality, but still, more than four in 10 Americans – 133.9 million – live in counties that have unhealthful levels of either ozone or particle pollution, where their health is at risk.”


The trends in this year’s report, which covers data collected by states, cities, counties, tribes and federal agencies in 2014-2016, confirm the ongoing challenges to reduce each pollutant in the changing political and outdoor climate.


“We can and should do more to save lives,” Stewart said. “The American Lung Association in Pennsylvania calls on our members of Congress to defend the Clean Air Act, currently under threat from those who want to weaken this effective public health law. We also call on the U.S. Environmental Protection Agency to implement and enforce the law instead of trying to roll back major safeguards such as the Clean Power Plan and cleaner cars, both steps that help us fight climate change and reduce air pollution.” 


For 19 years, “State of the Air” has provided a report card on the two most widespread outdoor air pollutants, ozone pollution, also known as smog, and particle pollution, also called soot. The report analyzes particle pollution in two ways: through average annual particle pollution levels and short-term spikes in particle pollution. Both ozone and particle pollution are dangerous to public health and can increase the risk of premature death and other serious health effects such as lung cancer, asthma attacks, cardiovascular damage, and developmental and reproductive harm.


Ozone Pollution in the Pittsburgh-New Castle-Weirton, PA-OH-WV metro area

Compared to the 2017 report, the Pittsburgh metro area experienced fewer unhealthy days of high ozone in this year’s report. Eight of the nine counties in the metro area monitored for ozone posted a smaller weighted average number of days with unhealthy levels of this pollutant.  (Only Westmoreland County showed an increase.)  In fact, for the third consecutive year of the report, the metro area reported its fewest unhealthy ozone days ever, driven by Allegheny County’s results.  However, five counties (Allegheny, Armstrong, Beaver, Indiana, and Washington) posted “F’ grades--still too many more than would protect people from this harmful pollutant.


“Ozone especially harms children, older adults and those with asthma and other lung diseases,” said Stewart. “When older adults or children with asthma breathe ozone-polluted air, too often they end up in the doctor’s office, the hospital or the emergency room. Ozone can even shorten life itself.”


This report documents how warmer temperatures brought by climate change make ozone more likely to form and harder to clean up. This year’s report also revealed that ozone levels increased in most cities nationwide, in large part due to warmer temperatures in 2016, the second hottest year on record in the U.S. Over the past decades, ozone pollution has decreased nationwide, because the nation has cleaned up major sources of the emissions that create ozone, especially coal-fired power plants and vehicles.  This effect has been particularly noticeable in the Ohio Valley.


Particle Pollution in the Pittsburgh-New Castle-Weirton, PA-OH-WV metro area

The 2018 report also found year-round particle pollution levels to be rather lower than in the 2017 report. Nationwide, the best progress in this year’s report came in reducing year-round levels of particle pollution. In the metro area, only Allegheny County showed an increase, and a continued failing grade.  The other six monitored counties showed improvement and again earned passing grades.


“Particle pollution is made of soot, chemicals, and tiny particles that come from coal-fired power plants, diesel emissions, wildfires and wood-burning devices. These particles are so small that they can lodge deep in the lungs and trigger asthma attacks, heart attacks and strokes, and can even be lethal,” said Stewart. “Year-round particle pollution levels have dropped thanks to the cleanup of coal-fired power plants and the retirement of old, dirty diesel engines.”


“State of the Air” 2018 also tracked short-term spikes in particle pollution, as these can be extremely dangerous and even lethal. The report found that the metro area, driven by Allegheny County’s results, had more days when short-term particle pollution reached unhealthy levels in 2014-2016. But of the eight counties in the metro area with results for this pollutant, only two (the other being Jefferson County, Ohio) showed an increase, and the remaining six equaled last year’s marks.  In fact, four counties (Armstrong and Westmoreland in Pennsylvania, and Brooke and Hancock in West Virginia) posted “A” grades for at least the third consecutive year, and are listed among the nation’s cleanest counties for this pollutant.


In other areas of the country, many of the daily spikes fine particle pollution were directly linked to weather patterns such as drought or to events such as wildfires, which are likely to increase because of climate change.  In some localities, high emissions from wood-burning devices have also been a factor.


While the report examined data from 2014-2016, this 19th annual report provides online information on air pollution trends back to the first report covering 1996-1998. Learn more about Pennsylvania and West Virginia’s rankings, as well as air quality in the Pittsburgh-New Castle-Weirton metro area and across the nation in the “State of the Air” report at For media interested in speaking with an expert about lung health and healthy air, contact the American Lung Association in Pennsylvania Communications Director Ewa Dworakowski by calling 717-971-1123 or 717-503-3903 (cell) or emailing [email protected] .




About the American Lung Association in Pennsylvania

The American Lung Association in Pennsylvania is the leading organization working to save lives by improving lung health and preventing lung disease, through research, education and advocacy. The work of the American Lung Association in Pennsylvania is focused on four strategic imperatives: to defeat lung cancer; to improve the air we breathe; to reduce the burden of lung disease on individuals and their families; and to eliminate tobacco use and tobacco-related diseases. For more information about the American Lung Association in Pennsylvania, a holder of the Better Business Bureau Wise Giving Guide Seal, or to support the work it does, call 1-800-LUNGUSA (1-800-586-4872) or visit:


American Lung Association in Pennsylvania

810 River Ave., Suite 140 • Pittsburgh, PA 15212


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