Radon in Knoxville, Tennessee

Is radon a problem in Knoxville, TN?

Yes, it can be. Knoxville is in Knox County, which EPA places in Zone 1, the highest radon-potential category: the predicted average indoor screening level is above 4 pCi/L. Levels vary from house to house, so a test is the only way to know your home's level.

Do new homes in Knoxville have to be built radon-resistant?

No. Knoxville's 2024 code, effective January 1, 2025, dropped the radon appendix the city had under its 2012 and 2018 codes. Unincorporated Knox County, outside city limits, still requires a passive radon system. Either way, ask your builder which radon features were installed and test after you move in: radon-resistant construction lowers the chance of high radon but doesn't replace a test. What your result means · Choosing a radon professional

How do I get a free radon test kit in Knoxville?

Order a free short-term kit from the Tennessee Radon Program online or by calling 1-800-232-1139. Place it on the lowest lived-in floor, about 3 feet off the floor, for 3 to 5 days, then mail it back right away; return postage is prepaid. How to test your home

What if my Knoxville home tests high for radon?

EPA recommends fixing your home at 4 pCi/L or higher and considering a fix between 2 and 4 pCi/L. Confirm a high short-term result with a second test, then hire an NRPP- or NRSB-certified mitigation professional; Tennessee doesn't license radon contractors. What your result means · Choosing a radon professional

Where can I learn more about radon in Knox County?

The Knox County, TN radon guide covers every permitting jurisdiction in the county, state test data and sources.

Sources: Knox County radon guide and its sources · EPA Map of Radon Zones: Tennessee · Tennessee Radon Program · EPA, Health Risk of Radon

Last reviewed October 17, 2026 by the Tennessee Radon Authority editorial team. How we research.