New Report: For Ozone Smog in Maryland, 8 Counties Post New Best Results But Most Counties Part of Metro Areas Ranking Among Worst 45 in Nation. Nine Locations Earn “A’s” for Daily Particle Pollution

The 2024 “State of the Air” report, released today by the American Lung Association, finds that Maryland’s air quality showed mixed results of best performances and continuing problems for some of the most harmful and widespread types of air pollution: fine particle pollution and ozone smog. Nationally, the report found that nearly four in ten people in the U.S. live in counties that had unhealthy levels of ozone or particle pollution.

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 report also tracked both daily spikes and year-round averages in particle pollution, which can be extremely dangerous and even deadly. The report grades air quality data for these pollutants over the three-year period 2020-2022 and is updated to reflect the new annual particle pollution standard that the U.S. Environmental Protection Agency (EPA) finalized in February. Air quality is measured in 16 of Maryland’s 24 jurisdictions, which are covered mostly by three metropolitan areas ranked in the 2024 “State of the Air” report.

“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 Maryland 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, Maryland has made strong commitments to healthy air policies, including the recent adoption of Advanced Clean Cars II and Advanced Clean Trucks which would facilitate the transition to zero emission vehicles. We are also calling on EPA to set long-overdue stronger national limits on ozone pollution.”

In Maryland, although counties more often had fewer days with unhealthy levels of ozone pollution, two metro areas, the Washington-Baltimore-Arlington, DC-VA-MD-WV-PA and the Philadelphia-Reading-Camden, PA-NJ-DE-MD, covering 16 of Maryland’s 24 jurisdictions, ranked 44th worst and 35th worst, respectively, out of 228 ranked metro areas across the country, though placing better than in last year’s report. These metro areas ranked 2nd worst and worst for ozone, respectively, in the Lung Association’s Mid-Atlantic region (defined for this report as DC, DE, MD, NJ, PA, VA, WV).

Eight Maryland jurisdictions improved for ozone smog, all posting their new best performances ever—Anne Arundel from an “F” to a “C,” Prince George’s from an “F” to its first passing grade (a “D”), and Baltimore City and Dorchester Counties from “C’s” to “B’s,” while the four others with smaller average numbers of days with unhealthy levels of ozone still kept last year’s grades—Baltimore and Harford Counties with “F’s,” Cecil with a “C” and Kent with a “B.” 

Three other counties remained unchanged from last year’s report, Calvert and Charles Counties, with “B’s,” and Garrett County, the only county in the state with an “A” grade for its zero days high in ozone smog, which continued for its seventh consecutive year among the nation’s cleanest counties. Only two Maryland counties, two fewer than in last year’s report, earned “F” grades—Baltimore and Harford, both in the Washington metro area. Only one Maryland county, Montgomery, had a slightly worse performance for ozone, but kept its “C” grade.

In contrast to Maryland’s lone “A” grade for ozone, nine jurisdictions reported “A” grades for the daily measure of fine particle pollution. Baltimore City improved from the “B” grade in last year’s report to post its first “A.” The other eight remained unchanged at “A” for their average of zero days per year high in particle pollution—Harford for its 3rd year in a row, Washington its 4th and Howard its 7th, while Dorchester, Kent and Prince George’s each marked their 9th, and Garrett and Montgomery each had their 10th consecutive “A” grade. The remaining two graded counties both earned “B” grades—Cecil being unchanged, and Baltimore County, to a better “B,” but not matching its best past performance of six straight years of reports with “A’s.”

Much like last year’s report, four of Maryland’s ten counties graded for the year-round measure of fine particle pollution had worse long-term averages in this year’s report, and the other six did better, though all changes were small. All Maryland counties earned passing grades based on the federal standard that was recently updated by the United States Environmental Protection Agency. One of the six improving counties, Baltimore, though worst in the state, posted a value that equaled its best mark previously achieved. Harford County improved but did not match its recent best past record low level. The four others—Garrett, Howard, Prince George’s, and Washington Counties—posted their respective best-ever values. Cecil, Dorchester, Kent and Montgomery Counties were those that recorded slightly worse long-term average levels.

The Lung Association’s 25th annual “State of the Air” report grades Americans’ 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 covers 2020-2022. All but three of Maryland’s counties are part of one of four metropolitan areas, for which some key findings include:

• The Washington-Baltimore-Arlington, DC-MD-VA-WV-PA metro area, covering the District of Columbia and 40 other counties and independent cities, includes Baltimore City and 14 Maryland counties set new best-ever values for ozone smog and for year-round particle pollution:
  • Baltimore County, MD again posted the worst performance for ozone in this year’s report, improving to its best-ever weighted average of 4.3 days per year with unhealth levels of ozone, continuing to earn an “F” grade as in last year’s report. The area’s ranking improved significantly, to 44th worst in the nation out of 228 metro areas, from 26th worst in last year’s report.
  • The Washington-Baltimore-Arlington metro area’s air quality very slightly improved for 24-hour particle pollution since last year’s report, and the area’s metro area rank improved slightly to 64th worst from 62nd most polluted in last year’s report, with fewer unhealthy air days.  For year-round particle pollution, the metro area improved just enough to set a new best-ever record, with the area’s rank improving to 90th worst from 79th worst last year.
  • Though the District of Columbia drove the metro area’s rankings for both the short-term and long-term measures of fine particle pollution, Baltimore County was worst in Maryland for both of these measures and (with Cecil County) earned a “B” for the daily measure.
• The 16-county Philadelphia-Reading-Camden, PA-NJ-DE-MD metro area, covering Cecil County, MD, improved for all three pollutants measured in the American Lung Association’s 2024 “State of the Air” report, including setting new best-ever values for ozone smog for the third consecutive year and for year-round particle pollution for the second straight year: 
  • Despite the improvement in ozone, the metro area was named 35th most polluted in the nation and worst for the measure in the Mid-Atlantic region (defined for this report as DC, DE, MD, NJ, PA, VA, WV).
  • The metro area’s worst grade for short-term particle pollution was a “C” in Philadelphia County, ranking the metro area at 73rd most polluted, an improvement over the area’s worst grade (a “D” in Delaware County, PA) and 55th worst rank in last year’s report.
  • For the year-round average level of particle pollution, the area’s worst counties, Delaware and Philadelphia, PA, and Camden, NJ, all received a failing grade for the same levels of pollution above the federal standard that was recently updated by the United States Environmental Protection Agency. The Philadelphia metro area ranked 65th worst in the nation, better than the area's ranking in last year's report of 46th worst when Camden County alone was worst in the metro area.
• The 5-county Salisbury-Cambridge, MD-DE metro area, covering Sussex County in Delaware, and four counties in Maryland, typically posts its worst (often, only) results in Dorchester County, Maryland:
  • Levels of ozone smog were highest in the metro area in Dorchester County, but it set the area’s new best-ever record and posted the area’s first “B” grade, improving the metro area’s rank from 65th worst in last year’s report to 116th worst.
  • For a 13th consecutive year (and Dorchester County’s 9th) the metro area ranked among the nation’s cleanest for the daily measure of particle pollution.
  • Based on Dorchester County’s results, along with the absence of data from Sussex County, the year-round average of particle pollution again worsened, though the levels are still low enough to rank the area as tied for the nation’s 16th cleanest among 204 metro areas, slightly worse than last year’s 9th best placement among 200 metro areas ranked.
• Of the counties remaining, Allegany County in the Cumberland, MD-WV metro area as well as Caroline County did not collect any data. The other two, Garrett and Kent, both posted good grades, including continuing “A” grades for short-term particle pollution and ranking 33rd and 41st cleanest, respectively, of 523 counties in the country with data for the long-term 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.  

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.