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Ozone air pollution worse, fine particle pollution levels best ever in Philadelphia-Reading-Camden metro area, 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) - Philadelphia, PA

The American Lung Association’s 2018 “State of the Air” report found that ozone air pollution in the 4-state, 16-county Philadelphia-Reading-Camden, PA-NJ-DE-MD metro area and throughout much of the Mid-Atlantic worsened when compared with last year’s report, even as fine particle pollution levels continued their steady improvement.  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. 


For the second year, the large metro area, centered in Philadelphia and covering northern Delaware and southern New Jersey, met the current national standard for year-round particle pollution, according to the 19th annual “State of the Air report.  The metro area ranked 12th worst of 187 across the country in the current report, despite posting its best-ever results for the sixth consecutive year.


For the daily measure of fine particle pollution, not only did all 10 counties posting grades either show improvement or equal last year’s performance, but for the first time ever, the Philadelphia metro area earned passing grades for all counties posting results.  The metro area’s rank also improved, from 20th worst last year to 31st worst of 201 metro areas in the current report.


For ozone, with the sole exception of Atlantic County, NJ, all monitored counties in the Philadelphia metro area posted worse results than in last year’s report.  As many other areas also had problems with ozone increases, the metro area’s rank nevertheless improved a bit from 22nd worst last year to 24th worst of 227 in the current report. 


Compared to the 2017 report, the Philadelphia-Reading-Camden metro area has seen a distinct increase in unhealthy days for ozone and a continuing gradual improvement in both measures of particle pollution.  This is in keeping with trends seen across the nation for both higher ozone and lower particle pollution levels than in last year’s report. In the case of year-round particle pollution, the Philadelphia metro area posted its 14th consecutive improvement in its worst county’s level since the 2004 report.


“The 2018 ‘State of the Air’ report finds that unhealthful levels of ozone in the Delaware Valley 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. 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 Philadelphia-Reading-Camden, PA-NJ-DE-MD metro area

Compared to the 2017 report, the Philadelphia-Reading-Camden metro area experienced more unhealthy days of high ozone in this year’s report. Of the 13 counties posting grades for ozone air pollution, 12 performed more poorly, with all six Pennsylvania Counties in the metro recording “F” grades.  Bucks and Philadelphia in PA, Camden and Gloucester Counties in NJ, Cecil County MD and New Castle County DE, all earned their 19th straight “F” for this pollutant in the Lung Association’s report.  Philadelphia County’s poor performance resulted in its ranking 42nd worst of 768 counties nationwide.


“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.


Particle Pollution in the Philadelphia-Reading-Camden, PA-NJ-DE-MD metro area

Nationwide, the best progress in this year’s report came in reducing year-round levels of particle pollution. 

With the exception of some counties now posting “Incomplete” grades, the 2018 report also found year-round particle pollution levels were all distinctly lower than in the 2017 report, continuing a steady decrease over at least six years. The nine counties that did have monitored values all performed much better than the national standard. Nevertheless, the two counties with the highest results traded the worst position in the metro area, from Philadelphia County (now ranking 20th worst of 497 counties nationwide) to Delaware County (now 19th). 


“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. According to the 2018 report, six counties had zero days when short-term particle pollution reached unhealthy levels in 2014-2016.  Three of them (Kent in DE, and Atlantic and Gloucester in NJ) continued their streak among the nation’s cleanest counties for the 7th straight year.  In addition, Cecil County, MD, Camden County, NJ, and Chester County, PA also joined the ranks of the country’s cleanest counties by moving to “A’s” from last year’s “B’s.”  Berks County, PA bettered the metro area’s worst grade by improving from a long-standing “F” to a “D.”  (Bucks County, PA, with its even longer history of straight “F’s,” was marked “Incomplete” for this year’s report.)  These improvements continue a general trend toward fewer short-term spikes in particle pollution in the Philadelphia-Reading-Camden, PA-NJ-DE-MD metro area.


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’s rankings, as well as air quality in the Delaware Valley 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

527 Plymouth Road, Suite 415 • Plymouth Meeting, PA 19462


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