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 Le Sueur County, Minnesota, and

Lincoln County, Minnesota, give the percentage contributions from specific air pollution sources.  The Le Sueur County Seat is Le Center, Minnesota, and the Lincoln County Seat is Ivanhoe, Minnesota.