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 Volusia County, Florida, and

Wakulla County, Florida, give the percentage contributions from specific air pollution sources.  The Volusia County Seat is De Land, Florida, and the Wakulla County Seat is Crawfordville, Florida.