Abstract: The Environmental Protection Agency (EPA) compiles data on emission tonnages of air pollutants for US counties.  US Air Quality Gradebook ("AirGrades") source sheets give the percentage contributions from specific air pollution sources.  This source sheet is for

Santa Cruz County, Arizona; Yavapai County, Arizona; and Yuma County, Arizona.  The Santa Cruz County Seat is Nogales, Arizona; the Yavapai County Seat is Prescott, Arizona; and the Yuma County Seat is Yuma, Arizona.