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 Cape Girardeau County, Missouri, and

Carroll County, Missouri, give the percentage contributions from specific air pollution sources.  The Cape Girardeau County Seat is Jackson, Missouri, and the Carroll County Seat is Carrollton, Missouri.