Washington Metro Area Sets Best-Ever Record for Ozone Smog, Still Reporting an F Grade and Places 2nd Worst in Mid-Atlantic Region; Ranked 4th Most Polluted in Region for Daily Particle Pollution

The Washington-Baltimore-Arlington, DC-MD-VA-WV-PA metro area was named 44th most polluted in the nation for ozone pollution and 2nd worst in the Mid-Atlantic region (defined for this report as DC, DE, MD, NJ, PA, VA, WV), with Philadelphia ranking as that region’s worst, according to the American Lung Association’s 2024 “State of the Air” report, released today. The ozone ranking marks a new best-ever record for the metro area, but its failing grade continues. The Washington-Baltimore-Arlington metro area’s year-round particle pollution also improved to a new best-ever level; and daily particle pollution improved slightly, but the metro area ranks fourth worst in the Mid-Atlantic region for the latter measure.

The Lung Association’s 25th annual “State of the Air” report grades exposure to unhealthy levels of ground-level ozone air pollution, annual particle pollution and short-term spikes in particle pollution over a three-year period. This year’s report includes air quality data from 2020-2022 and is updated to reflect the new annual particle pollution standard that the U.S. Environmental Protection Agency (EPA) finalized in February.

“In the 25 years that the American Lung Association has been doing our ‘State of the Air’ report, we have seen incredible improvement in the nation’s air quality. Unfortunately, more than 131 million people still live in places with unhealthy levels of air pollution, and the Washington-Baltimore-Arlington metro area still has work to do,” said Aleks Casper, Director of Advocacy for the American Lung Association. “Climate change is making air pollution more likely to form and more difficult to clean up. There are more actions we can and must take to improve air quality, the district has made strong commitments to healthy air policies, including the recent adoption of Advanced Clean Cars II which would facilitate the transition to zero emission vehicles.  The American Lung Association supports the district’s ongoing commitment and opposes any policies that would threaten forward progress. We are also calling on EPA to set long-overdue stronger national limits on ozone pollution.”

Ground-level Ozone Pollution in the Washington-Baltimore-Arlington metro area:

The “State of the Air” report looked at levels of ozone “smog,” the air pollutant affecting the largest number of  people in the United States. The metro area ranked 44th worst in the nation for ozone pollution. The ranking was based on the area’s worst county’s average number of unhealthy days—4.3 days per year, an F grade, in Baltimore County, MD. This was better than the area's ranking in last year's report of 26th worst, with 6.7 days per year, also an F grade. 

Particle Pollution in the Washington-Baltimore-Arlington metro area:

The report also tracked short-term spikes in particle pollution, which can be extremely dangerous and even deadly. The metro area ranked 64th worst in the nation for short-term particle pollution. The ranking was based on the area’s worst county’s average number of unhealthy days—1.7 days per year, a C grade, in the District of Columbia. This was better than the area's ranking in last year's report of 62nd worst, with 1.8 days per year, also a C grade.

For the year-round average level of particle pollution, the District was the area’s worst, and received a passing grade for pollution levels below the federal standard that was recently updated by the United States Environmental Protection Agency. The metro area ranked 90th worst in the nation. This was better than the area's ranking in last year's report of 79th worst in the nation.

In addition to the Washington-Baltimore-Arlington metro area, other notable findings across the Mid-Atlantic region include:

• The Philadelphia-Reading-Camden (PA-NJ-DE-MD) metro area improved for all three pollutant measures in the report, including setting new record best-ever values for ozone smog and year-round particle pollution. Despite improvement in ozone, the metro area still earns a failing grade and is now the worst ranked in the mid-Atlantic region.
• After consistently making the cleanest cities list for daily particle pollution over a recent decade of reports, the Richmond, VA metro area has fallen from the list but still earns a B grade for the measure; and continues to have best-ever results for ozone smog for fourth consecutive year.
• The Virginia Beach-Norfolk, VA-NC metro area (Hampton Roads) ranks among the cleanest in the nation for short-term particle pollution for ninth consecutive year; ozone smog earns a B grade, but is worse than the last three reports, falling from the nation’s cleanest for the measure.

The “State of the Air” report found that nationally, more than 131 million people live in an area that received a failing grade for at least one measure of air pollution, and 43.9 million people live in areas with failing grades for all three measures. In the three years covered by this report, individuals in the U.S. experienced the highest number of days when particle pollution reached “very unhealthy” and “hazardous” levels in the history of reporting the “State of the Air.” Communities of color are disproportionately exposed to unhealthy air and are also more likely to be living with one or more chronic conditions that make them more vulnerable to air pollution, including asthma, diabetes and heart disease. The report found that a person of color in the U.S. is more than twice as likely as a white individual to live in a community with a failing grade on all three pollution measures.

Both ozone and particle pollution can cause premature death and other serious health effects such as asthma attacks, heart attacks, strokes, preterm births and impaired cognitive functioning later in life. Particle pollution can also cause lung cancer.

The District has made strong commitments to healthy air policies, including the recent adoption of Advanced Clean Cars II which would facilitate the transition to zero emission vehicles.  The American Lung Association supports the district’s ongoing commitment and opposes any policies that would threaten forward progress.

EPA recently finalized new air pollution rules that will help clean up particle pollution and address climate change. Now, the Lung Association is urging EPA to set long overdue stronger national limits on ozone pollution. Stronger limits would help people protect themselves and drive cleanup of polluting sources across the country. See the full report results and sign the petition at Lung.org/SOTA.