Tennessee: 95 counties covered
Of 95 rated Tennessee counties, 38 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.
- Shelby County
- Davidson County
- Knox County
- Hamilton County
- Rutherford County
- Williamson County
- Montgomery County
- Sumner County
- Wilson County
- Sullivan County
- Blount County
- Washington County
- Bradley County
- Maury County
- Madison County
- Sevier County
- Putnam County
- Anderson County
- Robertson County
- Greene County
- Hamblen County
- Cumberland County
- Tipton County
- Loudon County
- Coffee County
- Hawkins County
- Jefferson County
- Dickson County
- Carter County
- McMinn County
- Roane County
- Bedford County
- Gibson County
- Monroe County
- Lawrence County
- Franklin County
- Fayette County
- Warren County
- Cheatham County
- Campbell County
- Marshall County
- Cocke County
- Lincoln County
- Dyer County
- Rhea County
- Weakley County
- Claiborne County
- Henry County
- Giles County
- Obion County
- Marion County
- White County
- Carroll County
- Henderson County
- Hardin County
- Macon County
- McNairy County
- Hickman County
- Hardeman County
- Grainger County
- Lauderdale County
- Overton County
- Scott County
- Morgan County
- DeKalb County
- Union County
- Smith County
- Fentress County
- Humphreys County
- Johnson County
- Polk County
- Chester County
- Unicoi County
- Sequatchie County
- Haywood County
- Benton County
- Wayne County
- Bledsoe County
- Cannon County
- Stewart County
- Grundy County
- Crockett County
- Meigs County
- Lewis County
- Jackson County
- Trousdale County
- Decatur County
- Perry County
- Houston County
- Clay County
- Hancock County
- Moore County
- Van Buren County
- Lake County
- Pickett County