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 Prentiss County, Mississippi, and

Quitman County, Mississippi, give the percentage contributions from specific air pollution sources.  The Prentiss County Seat is Booneville, Mississippi, and the Quitman County Seat is Marks, Mississippi.