Kentucky Radon Levels
30Zone 1 (High)
82Zone 2 (Moderate)
8Zone 3 (Low)
25% of counties in Kentucky 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 |
|---|---|---|
| Adair County | Zone 1 | Highest Potential |
| Allen County | Zone 1 | Highest Potential |
| Anderson County | Zone 2 | Moderate Potential |
| Ballard County | Zone 3 | Lowest Potential |
| Barren County | Zone 1 | Highest Potential |
| Bath County | Zone 2 | Moderate Potential |
| Bell County | Zone 2 | Moderate Potential |
| Boone County | Zone 2 | Moderate Potential |
| Bourbon County | Zone 1 | Highest Potential |
| Boyd County | Zone 2 | Moderate Potential |
| Boyle County | Zone 1 | Highest Potential |
| Bracken County | Zone 2 | Moderate Potential |
| Breathitt County | Zone 2 | Moderate Potential |
| Breckinridge County | Zone 2 | Moderate Potential |
| Bullitt County | Zone 1 | Highest Potential |
| Butler County | Zone 2 | Moderate Potential |
| Caldwell County | Zone 2 | Moderate Potential |
| Calloway County | Zone 3 | Lowest Potential |
| Campbell County | Zone 2 | Moderate Potential |
| Carlisle County | Zone 3 | Lowest Potential |
| Carroll County | Zone 2 | Moderate Potential |
| Carter County | Zone 2 | Moderate Potential |
| Casey County | Zone 1 | Highest Potential |
| Christian County | Zone 2 | Moderate Potential |
| Clark County | Zone 1 | Highest Potential |
| Clay County | Zone 2 | Moderate Potential |
| Clinton County | Zone 2 | Moderate Potential |
| Crittenden County | Zone 2 | Moderate Potential |
| Cumberland County | Zone 1 | Highest Potential |
| Daviess County | Zone 2 | Moderate Potential |
| Edmonson County | Zone 2 | Moderate Potential |
| Elliott County | Zone 2 | Moderate Potential |
| Estill County | Zone 2 | Moderate Potential |
| Fayette County | Zone 1 | Highest Potential |
| Fleming County | Zone 2 | Moderate Potential |
| Floyd County | Zone 2 | Moderate Potential |
| Franklin County | Zone 1 | Highest Potential |
| Fulton County | Zone 3 | Lowest Potential |
| Gallatin County | Zone 2 | Moderate Potential |
| Garrard County | Zone 2 | Moderate Potential |
| Grant County | Zone 2 | Moderate Potential |
| Graves County | Zone 3 | Lowest Potential |
| Grayson County | Zone 2 | Moderate Potential |
| Green County | Zone 1 | Highest Potential |
| Greenup County | Zone 2 | Moderate Potential |
| Hancock County | Zone 2 | Moderate Potential |
| Hardin County | Zone 2 | Moderate Potential |
| Harlan County | Zone 2 | Moderate Potential |
| Harrison County | Zone 1 | Highest Potential |
| Hart County | Zone 1 | Highest Potential |
| Henderson County | Zone 2 | Moderate Potential |
| Henry County | Zone 2 | Moderate Potential |
| Hickman County | Zone 3 | Lowest Potential |
| Hopkins County | Zone 2 | Moderate Potential |
| Jackson County | Zone 2 | Moderate Potential |
| Jefferson County | Zone 1 | Highest Potential |
| Jessamine County | Zone 1 | Highest Potential |
| Johnson County | Zone 2 | Moderate Potential |
| Kenton County | Zone 2 | Moderate Potential |
| Knott County | Zone 2 | Moderate Potential |
| Knox County | Zone 2 | Moderate Potential |
| Larue County | Zone 2 | Moderate Potential |
| Laurel County | Zone 2 | Moderate Potential |
| Lawrence County | Zone 2 | Moderate Potential |
| Lee County | Zone 2 | Moderate Potential |
| Leslie County | Zone 2 | Moderate Potential |
| Letcher County | Zone 2 | Moderate Potential |
| Lewis County | Zone 2 | Moderate Potential |
| Lincoln County | Zone 1 | Highest Potential |
| Livingston County | Zone 2 | Moderate Potential |
| Logan County | Zone 2 | Moderate Potential |
| Lyon County | Zone 2 | Moderate Potential |
| McCracken County | Zone 3 | Lowest Potential |
| McCreary County | Zone 2 | Moderate Potential |
| McLean County | Zone 2 | Moderate Potential |
| Madison County | Zone 2 | Moderate Potential |
| Magoffin County | Zone 2 | Moderate Potential |
| Marion County | Zone 1 | Highest Potential |
| Marshall County | Zone 3 | Lowest Potential |
| Martin County | Zone 2 | Moderate Potential |
| Mason County | Zone 2 | Moderate Potential |
| Meade County | Zone 2 | Moderate Potential |
| Menifee County | Zone 2 | Moderate Potential |
| Mercer County | Zone 1 | Highest Potential |
| Metcalfe County | Zone 1 | Highest Potential |
| Monroe County | Zone 1 | Highest Potential |
| Montgomery County | Zone 2 | Moderate Potential |
| Morgan County | Zone 2 | Moderate Potential |
| Muhlenberg County | Zone 2 | Moderate Potential |
| Nelson County | Zone 1 | Highest Potential |
| Nicholas County | Zone 2 | Moderate Potential |
| Ohio County | Zone 2 | Moderate Potential |
| Oldham County | Zone 2 | Moderate Potential |
| Owen County | Zone 2 | Moderate Potential |
| Owsley County | Zone 2 | Moderate Potential |
| Pendleton County | Zone 1 | Highest Potential |
| Perry County | Zone 2 | Moderate Potential |
| Pike County | Zone 2 | Moderate Potential |
| Powell County | Zone 2 | Moderate Potential |
| Pulaski County | Zone 1 | Highest Potential |
| Robertson County | Zone 1 | Highest Potential |
| Rockcastle County | Zone 2 | Moderate Potential |
| Rowan County | Zone 2 | Moderate Potential |
| Russell County | Zone 1 | Highest Potential |
| Scott County | Zone 1 | Highest Potential |
| Shelby County | Zone 2 | Moderate Potential |
| Simpson County | Zone 2 | Moderate Potential |
| Spencer County | Zone 2 | Moderate Potential |
| Taylor County | Zone 1 | Highest Potential |
| Todd County | Zone 2 | Moderate Potential |
| Trigg County | Zone 2 | Moderate Potential |
| Trimble County | Zone 2 | Moderate Potential |
| Union County | Zone 2 | Moderate Potential |
| Warren County | Zone 1 | Highest Potential |
| Washington County | Zone 2 | Moderate Potential |
| Wayne County | Zone 2 | Moderate Potential |
| Webster County | Zone 2 | Moderate Potential |
| Whitley County | Zone 2 | Moderate Potential |
| Wolfe County | Zone 2 | Moderate Potential |
| Woodford County | Zone 1 | Highest Potential |