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 Hickory County, Missouri, and

Holt County, Missouri, give the percentage contributions from specific air pollution sources.  The Hickory County Seat is Hermitage, Missouri, and the Holt County Seat is Oregon, Missouri.