American Lung Association Report: Many Marylanders Exposed to Less Ozone Smog Air Pollution, But Four Counties Still Earn “F” Grades; Most Counties in Metro Area Ranking Among Worst 30 in Nation

1 in 3 Nationwide Exposed to Unhealthy Air
The 2023 “State of the Air” report, released today by the American Lung Association, found that nationally, nearly 120 million people, or more than one in three, in the U.S. live in counties that had unhealthy levels for some of the most harmful and widespread types of air pollution: ozone or particle pollution. Locally, air quality showed mixed results.

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 Combined Statistical Areas, covering 15 of Maryland’s 23 counties, ranked 26th worst and 28th worst, respectively, out of 227 metro areas across the country, both worse than in last year’s report. Four Maryland Counties, two fewer than in last year’s report, earned ‘F’ grades, all in the Washington metro area: Anne Arundel, Baltimore, Harford, and Prince George’s. Only four Maryland counties—Baltimore, Carroll, Frederick, and Montgomery—posted worse grades for ozone while seven counties improved, and three remained the same. One of the lattermost group was Garrett County, the only county in the state with an ‘A’ grade for its zero days high in ozone smog, continuing for its sixth consecutive year among the nation’s cleanest counties.

In contrast, although half of Maryland’s counties graded for the year-round measure of fine particles—Baltimore, Cecil, Dorchester, Harford and Prince George’s—had worse long-term averages in this year’s report, the ranking for the Washington-Baltimore-Arlington metro area still improved slightly, from 75th worst to 79th worst in the nation.  Four Maryland counties improved for this measure and one remained the same, while the remaining 13 counties did not collect data. And although no county in Maryland improved for the short-term measure of fine particles, performance there was typically good, with seven counties continuing to earn ‘A’ grades, posting zero days with unhealthy levels of fine particle pollution, the other three graded jurisdictions earning ‘B’s’: Baltimore City remained the same, and only two (Baltimore and Cecil Counties) posted worse weighted averages. 

“As we can see from this year’s report data, there is much work to be done in the Washington-Baltimore-Arlington metro area to improve our air quality,” said Aleks Casper, Advocacy Director, DC, MD, VA, DE for the Lung Association. “Even one poor air quality day is one too many for our residents at highest risk, such as children, older adults, individuals who are pregnant and those living with chronic disease. That’s why we are calling on lawmakers at the local, state and federal levels to take action to ensure that everyone has clean air to breathe.”

Nationally, the report found that ozone pollution has generally improved across the nation, thanks in large part to the success of the Clean Air Act. However, more work remains to fully clean up harmful pollution, and short-term particle pollution continues to get worse. In addition, some communities bear a greater burden of air pollution. Out of the nearly 120 million people who live in areas with unhealthy air quality, a disproportionate number – more than 64 million (54%) – are people of color. In fact, people of color were 64% more likely than white people to live in a county with a failing grade for at least one measure, and 3.7 times as likely to live in a county with a failing grade for all three measures. 

The Lung Association’s 24th 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 2019-2021. 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 13 Maryland Counties and matched its best-ever performance for ozone smog, but worsened for both measures of fine particle pollution:
o    Baltimore County, MD displaced Harford County, MD as the county in the entire metro area with the worst performance for ozone in this year’s report, earning an ‘F’ grade with the same weighted average of 6.7 days annually with unhealthy levels of ozone recorded in last year’s report. Though best-ever for the metro area, the area’s ranking worsened to 26th worst in the nation from 30th in last year’s report out of 227 metro areas.
o    The Washington-Baltimore-Arlington metro area’s air quality worsened for 24-hour and year-round particle pollution since last year’s report. The metro area ranked tied for 62nd most polluted for short-term particle pollution (compared to tied for 63rd in last year’s report), with more unhealthy air days. 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 earned a “B” for the daily measure. 

•    The 16-county Philadelphia-Reading-Camden, PA-NJ-DE-MD metro area, which includes Maryland’s Cecil County, improved for two measures of air pollution and remained unchanged for the third: 
o    Although the metro area posted its fewest-ever days with unhealthy levels of ozone smog, Philadelphia County continued to drive the area’s ranking with its 6.5 days (an ‘F’ grade), a high enough weighted average number of high ozone days for the metro area to rank 28th worst in the nation, worse than 29th most polluted last year. Cecil County earned a ‘C.’
o    Although the weighted average number of days with unhealthy levels of fine particle pollution in Delaware County, PA remained unchanged from last year’s report (2.3 days, earning a ‘D’ grade), the metro area’s rank improved from 44th in last year’s report to 55th this year since poorer performance for this pollutant measure was widespread across the country. After five years in a row with ‘A’ grades, Cecil County worsened to a ‘B.’
o    The area’s worst year-round average level of fine particle pollution (measured in Camden County, NJ) improved significantly to its best ever; the metro area had ranked as the 18th most polluted city in the nation, but this year has improved to 46th worst. Cecil County worsened very slightly from last year’s report to its second-best level ever.

•    Results from the 5-county Salisbury-Cambridge, MD-DE metro area were led by Dorchester County, MD. 
o    While Sussex County, DE earned an ‘A’ grade for ozone, Dorchester County improved only slightly, and continued to earn a ‘C’ grade, but the metro area’s rank still worsened from 75th worst in last year’s report to 65th worst.
o    Not only did Dorchester, along with Sussex County, DE, post zero days high in the daily measure of fine particle pollution, helping to rank the area among the nation’s cleanest for the 12th straight year, but…
o    Dorchester County’s long-term average level of particle pollution was low enough, along with the absence this year of data from Sussex County, DE, to place the metro area in a tie for 9th cleanest in the country 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 40th and 44th cleanest, respectively, of 517 counties in the country with data for the long-term measure.

The American Lung Association is calling on President Biden to urgently move forward on several measures to clean up air pollution nationwide, including new pollution limits on ozone and particle pollution and new measures to clean up power plants and vehicles. See the full report results and sign the petition at

“Maryland has an opportunity to make a significant commitment to the health and wellbeing of all Marylanders by moving forward with a suite of policies that would accelerate the transition to zero emission vehicles of all sizes.  We urge Maryland to move quickly with the adoption and implementation policies to cut harmful pollution from cars, trucks and buses,” said Casper.
For more information, contact:

Valerie Gleason
[email protected]

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