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 Juneau Borough, Alaska, and

Kenai Peninsula Borough, Alaska, give the percentage contributions from specific air pollution sources.  The Juneau Borough Seat is Juneau, Alaska, and the Kenai Peninsula Borough Seat is Soldotna, Alaska.