A new air quality report has determined where in Maryland to find the highest and lowest levels of air pollution. The American Lung Association released its "State of the Air 2018" report this week and concluded that ozone pollution overall worsened significantly in America from 2014-2016 compared to its previous report, which looked at 2013-2015.

Many cities had more days when ground-level ozone — known as "smog" — reached unhealthy levels, the report said. Baltimore ranked No. 17 for the number of high-ozone days among 227 metropolitan areas. When it comes to the number of smoggy or high-ozone days in Maryland, only one county received an "A" grade and eight received failing grades. The lone Maryland jurisdiction given an "A" for both smog and soot levels was Garrett County.



But it wasn't all bad news. There were not as many spikes in particle pollution, known as "soot." For soot levels, 10 counties received "A" grades, and zero counties received failing grades. Many counties across the country received a DNC grade, indicating there was no monitor collecting data.

Here are the grades for the counties in Maryland that provided enough data to assess: Anne Arundel Smog grade: F Soot grade: A

Baltimore City Smog grade: F Soot grade: B

Baltimore County Smog grade: F Soot grade: A

Calvert County Smog grade: C Soot grade: DNC

Carroll County Smog grade: C Soot grade: DNC

Cecil County Smog grade: F Soot grade: A

Charles County Smog grade: F Soot grade: DNC

Dorchester County Smog grade: C Soot grade: A

Frederick County Smog grade: C Soot grade: DNC

Garrett County Smog grade: A Soot grade: A

Harford County Smog grade: F Soot grade: A

Howard County Smog grade: DNC Soot grade: A

Kent County Smog grade: F Soot grade: A

Montgomery County Smog grade: C Soot grade: A

Prince George's County Smog grade: F Soot grade: A

Washington County Smog grade: C Soot grade: B

More than 40 percent of Americans live in counties with an unhealthy level of either smog or soot, the study said.

California had many cities with the most air pollution. Eight of the 10 smoggiest cities and eight of the 10 most soot-ridden cities are in the Golden State. Among these were Los Angeles, Fresno, Bakersfield and Visalia.

"Los Angeles remains the city with the worst ozone pollution as it has for nearly the entire history of the report," the authors wrote.

For the first time, Fairbanks, Alaska, ranked as one of the most polluted for year-round soot levels, while Bakersfield, California, maintained its badge of shame as the city with the worst short-term soot levels. The study used the latest quality-assured data available and examined soot levels in two ways: averaged year-round and over short-term levels, defined as 24 hours. The analysis also used a weighted average number of days. Click here to read the full methodology.