Tennessee Radon Authority
Updated October 17, 2026

95 county guides · Data snapshot October 16, 2026

Tennessee radon by county: all 95 county guides

Start with the county, not the statewide label. Compare EPA zone classifications with carefully reviewed Tennessee dashboard observations, then open the local guide for building-code findings, testing access, and the evidence behind each number.

95county guides
38EPA Zone 1 counties
34counties with verified figures
10verified averages at or above 4.0 pCi/L
Showing all 95 counties
Division
EPA zone
Evidence

County directory

Alphabetical · figures in pCi/L

All 95 Tennessee counties, A–Z

Each guide covers the county’s EPA radon zone, local building-code rules for new homes, state test data where it could be confirmed, and how to test.

Town radon guides

Whether new homes must be built radon-resistant depends on the town that issues the permit. These towns have their own short guides.

Read the gaps as carefully as the numbers.

The dashboard figures come from a small, self-selected set of tests—not a census of county homes. A dash means a value was unavailable or intentionally withheld, never that the level was zero. “No events” means no tests were mapped in the 2022–2023 dashboard dataset; it does not mean no radon. EPA zones describe broad potential, not the result in a particular home.

VerifiedTwo or more consistent, county-confirmed tooltip reads.
ProvisionalA single or partial observation, shown with its caveat.
WithheldCould not be isolated, reproduced, or trusted.
No eventsNo tests mapped in the dataset—not a safety finding.