Abstract: The Environmental Protection Agency (EPA) compiles data on emission tonnages of air pollutants for US counties.  US Air Quality Gradebook ("AirGrades") source sheets such as this one for Clay County, West Virginia, and

Doddridge County, West Virginia, give the percentage contributions from specific air pollution sources.  The Clay County Seat is Clay, West Virginia, and the Doddridge County Seat is West Union, West Virginia.