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 Gaston County, North Carolina, and

Gates County, North Carolina, give the percentage contributions from specific air pollution sources.  The Gaston County Seat is Gastonia, North Carolina, and the Gates County Seat is Gatesville, North Carolina.