Jurisdiction by jurisdiction
County rules can differ from the nearest city. We track residential code editions and radon appendix adoption separately where the record allows.
Start here
Test the building. Then act on the number.
County averages and EPA zones are useful context, but neither can tell you the radon level in a particular home.
A clear four-step path
- Choose your county
See the local risk zone, code findings, available testing data, and testing-access picture.
- Test the lowest lived-in level
Use a home kit or hire a certified measurement professional. Follow the device instructions exactly.
- Read the result in context
EPA recommends fixing at 4 pCi/L or more and considering action between 2 and 4 pCi/L.
- Mitigate and retest
If levels are elevated, use a qualified professional and confirm the reduction with a follow-up test.
All 95 counties
Find the guide written for your county.
Each page separates verified facts from open questions and links back to the sources behind the findings.
95 counties
Anderson County
Bedford County
Benton County
Bledsoe County
Blount County
Bradley County
Campbell County
Cannon County
Carroll County
Carter County
Cheatham County
Chester County
Claiborne County
Clay County
Cocke County
Coffee County
Crockett County
Cumberland County
Davidson County
DeKalb County
Decatur County
Dickson County
Dyer County
Fayette County
Fentress County
Franklin County
Gibson County
Giles County
Grainger County
Greene County
Grundy County
Hamblen County
Hamilton County
Hancock County
Hardeman County
Hardin County
Hawkins County
Haywood County
Henderson County
Henry County
Hickman County
Houston County
Humphreys County
Jackson County
Jefferson County
Johnson County
Knox County
Lake County
Lauderdale County
Lawrence County
Lewis County
Lincoln County
Loudon County
Macon County
Madison County
Marion County
Marshall County
Maury County
McMinn County
McNairy County
Meigs County
Monroe County
Montgomery County
Moore County
Morgan County
Obion County
Overton County
Perry County
Pickett County
Polk County
Putnam County
Rhea County
Roane County
Robertson County
Rutherford County
Scott County
Sequatchie County
Sevier County
Shelby County
Smith County
Stewart County
Sullivan County
Sumner County
Tipton County
Trousdale County
Unicoi County
Union County
Van Buren County
Warren County
Washington County
Wayne County
Weakley County
White County
Williamson County
Wilson County
No county matches that search.
Why these guides are different
Local rules. Visible uncertainty. Primary sources.
Data without false precision
If a dashboard value cannot be reproduced or belongs to a larger health region, it stays off the county page.
Directory checks are dated
Certified-professional listings change. Each search is time-stamped and treated as a floor, not a complete census.
Open questions stay open
“Not found online” is not rewritten as “does not exist.” Unverified claims remain labeled and specific.
Statewide reference desk
Go straight to the official source.
Use these statewide resources alongside the local reporting in each county guide.
Tennessee Radon Testing dashboardState testing data for 2022–2023. County tooltips and regional band charts require careful interpretation.Open dashboard →EPA map of radon zonesRegional potential based on geology, measurements, soil, aerial radioactivity, and foundation types.See EPA zones →Find a qualified professionalEPA explains how to find credentialed measurement and mitigation providers through recognized programs.See EPA guidance →
Your county guide is the next step.
See what is known locally, what still needs verification, and how to test the home in front of you.