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 Wade Hampton Census Area, Alaska, and

Wrangell-Petersburg Census Area, Alaska, give the percentage contributions from specific air pollution sources.  Hooper Bay, Alaska, is in the Wade Hampton Census Area, and Petersburg, Alaska, is in the Wrangell-Petersburg Census Area.