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 Marlboro County, South Carolina, and

McCormick County, South Carolina, give the percentage contributions from specific air pollution sources.  The Marlboro County Seat is Bennettsville, South Carolina, and the McCormick County Seat is McCormick, South Carolina.