Tennessee Radon Levels
39Zone 1 (High)
32Zone 2 (Moderate)
24Zone 3 (Low)
41% of counties in Tennessee are classified as EPA Zone 1 (highest radon potential), meaning predicted average indoor radon levels exceed 4 pCi/L — the EPA action level. The EPA recommends that all homes be tested for radon, regardless of zone classification.
| County | EPA Zone | Risk Level |
|---|---|---|
| Anderson County | Zone 1 | Highest Potential |
| Bedford County | Zone 1 | Highest Potential |
| Benton County | Zone 2 | Moderate Potential |
| Bledsoe County | Zone 3 | Lowest Potential |
| Blount County | Zone 1 | Highest Potential |
| Bradley County | Zone 1 | Highest Potential |
| Campbell County | Zone 3 | Lowest Potential |
| Cannon County | Zone 2 | Moderate Potential |
| Carroll County | Zone 3 | Lowest Potential |
| Carter County | Zone 2 | Moderate Potential |
| Cheatham County | Zone 2 | Moderate Potential |
| Chester County | Zone 2 | Moderate Potential |
| Claiborne County | Zone 1 | Highest Potential |
| Clay County | Zone 2 | Moderate Potential |
| Cocke County | Zone 2 | Moderate Potential |
| Coffee County | Zone 2 | Moderate Potential |
| Crockett County | Zone 3 | Lowest Potential |
| Cumberland County | Zone 3 | Lowest Potential |
| Davidson County | Zone 1 | Highest Potential |
| Decatur County | Zone 2 | Moderate Potential |
| DeKalb County | Zone 2 | Moderate Potential |
| Dickson County | Zone 2 | Moderate Potential |
| Dyer County | Zone 3 | Lowest Potential |
| Fayette County | Zone 3 | Lowest Potential |
| Fentress County | Zone 2 | Moderate Potential |
| Franklin County | Zone 3 | Lowest Potential |
| Gibson County | Zone 3 | Lowest Potential |
| Giles County | Zone 1 | Highest Potential |
| Grainger County | Zone 1 | Highest Potential |
| Greene County | Zone 1 | Highest Potential |
| Grundy County | Zone 3 | Lowest Potential |
| Hamblen County | Zone 1 | Highest Potential |
| Hamilton County | Zone 2 | Moderate Potential |
| Hancock County | Zone 1 | Highest Potential |
| Hardeman County | Zone 3 | Lowest Potential |
| Hardin County | Zone 2 | Moderate Potential |
| Hawkins County | Zone 1 | Highest Potential |
| Haywood County | Zone 3 | Lowest Potential |
| Henderson County | Zone 2 | Moderate Potential |
| Henry County | Zone 3 | Lowest Potential |
| Hickman County | Zone 1 | Highest Potential |
| Houston County | Zone 2 | Moderate Potential |
| Humphreys County | Zone 1 | Highest Potential |
| Jackson County | Zone 1 | Highest Potential |
| Jefferson County | Zone 1 | Highest Potential |
| Johnson County | Zone 2 | Moderate Potential |
| Knox County | Zone 1 | Highest Potential |
| Lake County | Zone 3 | Lowest Potential |
| Lauderdale County | Zone 3 | Lowest Potential |
| Lawrence County | Zone 1 | Highest Potential |
| Lewis County | Zone 1 | Highest Potential |
| Lincoln County | Zone 1 | Highest Potential |
| Loudon County | Zone 1 | Highest Potential |
| McMinn County | Zone 1 | Highest Potential |
| McNairy County | Zone 2 | Moderate Potential |
| Macon County | Zone 1 | Highest Potential |
| Madison County | Zone 1 | Highest Potential |
| Marion County | Zone 2 | Moderate Potential |
| Marshall County | Zone 1 | Highest Potential |
| Maury County | Zone 3 | Lowest Potential |
| Meigs County | Zone 1 | Highest Potential |
| Monroe County | Zone 1 | Highest Potential |
| Montgomery County | Zone 2 | Moderate Potential |
| Moore County | Zone 1 | Highest Potential |
| Morgan County | Zone 3 | Lowest Potential |
| Obion County | Zone 3 | Lowest Potential |
| Overton County | Zone 2 | Moderate Potential |
| Perry County | Zone 1 | Highest Potential |
| Pickett County | Zone 2 | Moderate Potential |
| Polk County | Zone 2 | Moderate Potential |
| Putnam County | Zone 2 | Moderate Potential |
| Rhea County | Zone 3 | Lowest Potential |
| Roane County | Zone 1 | Highest Potential |
| Robertson County | Zone 2 | Moderate Potential |
| Rutherford County | Zone 1 | Highest Potential |
| Scott County | Zone 3 | Lowest Potential |
| Sequatchie County | Zone 3 | Lowest Potential |
| Sevier County | Zone 2 | Moderate Potential |
| Shelby County | Zone 3 | Lowest Potential |
| Smith County | Zone 1 | Highest Potential |
| Stewart County | Zone 2 | Moderate Potential |
| Sullivan County | Zone 1 | Highest Potential |
| Sumner County | Zone 2 | Moderate Potential |
| Tipton County | Zone 3 | Lowest Potential |
| Trousdale County | Zone 1 | Highest Potential |
| Unicoi County | Zone 2 | Moderate Potential |
| Union County | Zone 1 | Highest Potential |
| Van Buren County | Zone 2 | Moderate Potential |
| Warren County | Zone 2 | Moderate Potential |
| Washington County | Zone 1 | Highest Potential |
| Wayne County | Zone 1 | Highest Potential |
| Weakley County | Zone 3 | Lowest Potential |
| White County | Zone 2 | Moderate Potential |
| Williamson County | Zone 1 | Highest Potential |
| Wilson County | Zone 1 | Highest Potential |