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

Dallas County, Texas; Dawson County, Texas; and Deaf Smith County, Texas.  The Dallas County Seat is Dallas, Texas; the Dawson County Seat is Lamesa, Texas; and the Deaf Smith County Seat is Hereford, Texas.