The air in Beaver County is among the worst in the region, according to a newly released report. The American Lung Association on Wednesday released its annual report that analyzes air quality across the country. Beaver County received an F grade for the level of ozone smog, alongside Allegheny and Washington counties. Lawrence County received an C grade, . Mercer County received a D grade. According to the report, the Pittsburgh metropolitan area covering 12 southwestern Pennsylvania counties, ranks as eighth worst in year-round particle pollution out of 184 areas studied.