Alabama: 67 counties covered
Of 67 rated Alabama counties, 13 are in EPA's highest radon-potential zone (Zone 1) — but every county page links to testing guidance regardless of zone, because a county rating is a county-wide average, not a reading for any one house.
- Jefferson County
- Madison County
- Mobile County
- Baldwin County
- Tuscaloosa County
- Shelby County
- Montgomery County
- Lee County
- Morgan County
- Limestone County
- Calhoun County
- Houston County
- Etowah County
- Marshall County
- Lauderdale County
- St. Clair County
- Cullman County
- Elmore County
- Talladega County
- DeKalb County
- Walker County
- Autauga County
- Blount County
- Russell County
- Colbert County
- Coffee County
- Jackson County
- Dale County
- Chilton County
- Tallapoosa County
- Covington County
- Escambia County
- Dallas County
- Chambers County
- Lawrence County
- Pike County
- Franklin County
- Marion County
- Geneva County
- Cherokee County
- Barbour County
- Winston County
- Randolph County
- Bibb County
- Clarke County
- Monroe County
- Marengo County
- Pickens County
- Butler County
- Macon County
- Henry County
- Cleburne County
- Fayette County
- Hale County
- Washington County
- Clay County
- Lamar County
- Crenshaw County
- Choctaw County
- Sumter County
- Conecuh County
- Coosa County
- Bullock County
- Wilcox County
- Lowndes County
- Perry County
- Greene County