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 Gallatin County, Illinois, and

Greene County, Illinois, give the percentage contributions from specific air pollution sources.  The Gallatin County Seat is Shawneetown, Illinois, and the Greene County Seat is Carrollton, Illinois.