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 Coconino County, Arizona, and

Gila County, Arizona, give the percentage contributions from specific air pollution sources.  The Coconino County Seat is Flagstaff, Arizona, and the Gila County Seat is Globe, Arizona.