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

Ionia County, Michigan; Iosco County, Michigan; and Iron County, Michigan.  The Ionia County Seat is Ionia, Michigan; the Iosco County Seat is Tawas City, Michigan; and the Iron County Seat is Crystal Falls, Michigan.