Radon in Kentucky

About 4 in 10 homes tested in Kentucky were at or above the EPA action level of 4 pCi/L.

20,870 homes tested, 2008–2017
  • Below 2 pCi/L: 34%
  • 2 to 4 pCi/L: 23%
  • 4 pCi/L or more: 43%
The line marks the EPA action level, 4 pCi/L.

The EPA puts 30 of Kentucky's 120 counties in Zone 1, its highest radon category, 82 in Zone 2 and 8 in Zone 3.

Every county in Kentucky

Sorted by the share of homes tested at or above 4 pCi/L. Select a county for local details and costs.

CountyHomes testedAt or above 4MedianEPA zone
Meade County
68%8.2 pCi/L2
Nelson County
66%6.3 pCi/L1
Hart County
66%8.0 pCi/L1
Owsley County5 tests––2
Warren County
62%6.3 pCi/L1
Wayne County
61%5.0 pCi/L2
Pulaski County
60%5.1 pCi/L1
Woodford County
58%4.9 pCi/L1
Taylor County
57%4.4 pCi/L1
Cumberland County12 tests––1
Jessamine County
56%4.7 pCi/L1
Fayette County
55%4.5 pCi/L1
Boyle County
54%4.4 pCi/L1
Bourbon County
54%4.8 pCi/L1
Monroe County
53%4.6 pCi/L1
Barren County
52%4.0 pCi/L1
Montgomery County
51%4.1 pCi/L2
Hardin County
50%4.0 pCi/L2
McLean County2 tests––2
Marion County
49%3.9 pCi/L1
Bullitt County
48%3.6 pCi/L1
Clinton County
48%3.5 pCi/L2
Larue County
47%3.7 pCi/L2
Scott County
47%3.6 pCi/L1
Harrison County
47%3.4 pCi/L1
Trimble County18 tests––2
Metcalfe County
46%3.5 pCi/L1
Powell County
45%3.2 pCi/L2
Estill County
44%3.2 pCi/L2
Adair County
43%3.8 pCi/L1
Franklin County
43%3.3 pCi/L1
Boone County
43%3.5 pCi/L2
Rockcastle County11 tests––2
Bath County12 tests––2
Caldwell County15 tests––2
Elliott County5 tests––2
Floyd County13 tests––2
Garrard County
40%2.6 pCi/L2
Jefferson County
39%2.7 pCi/L1
Madison County
39%2.9 pCi/L2
Carroll County
39%3.5 pCi/L2
Mercer County
38%2.7 pCi/L1
Shelby County
38%3.0 pCi/L2
Oldham County
37%2.7 pCi/L2
Henry County
37%3.2 pCi/L2
Fleming County17 tests––2
Owen County
36%2.5 pCi/L2
Christian County
36%3.2 pCi/L2
Lyon County13 tests––2
Lincoln County
36%2.8 pCi/L1
Grant County
33%2.5 pCi/L2
Lewis County8 tests––2
Casey County
33%3.1 pCi/L1
Simpson County
33%2.6 pCi/L2
Green County
32%2.5 pCi/L1
Letcher County19 tests––2
Carter County
32%2.2 pCi/L2
Logan County
32%2.4 pCi/L2
Breckinridge County
31%2.5 pCi/L2
Spencer County
31%2.5 pCi/L2
Allen County
29%1.9 pCi/L1
Clark County
29%2.4 pCi/L1
Grayson County
28%2.2 pCi/L2
Washington County
27%2.4 pCi/L2
Pendleton County
27%1.9 pCi/L1
Campbell County
26%2.3 pCi/L2
Kenton County
26%2.3 pCi/L2
Anderson County
25%2.2 pCi/L2
Crittenden County7 tests––2
Gallatin County13 tests––2
Harlan County4 tests––2
Mason County
25%2.6 pCi/L2
Robertson County4 tests––1
Russell County
25%2.9 pCi/L1
Union County8 tests––2
Henderson County
24%2.3 pCi/L2
Knott County11 tests––2
Calloway County
22%2.4 pCi/L3
Trigg County
22%2.4 pCi/L2
Laurel County
22%1.9 pCi/L2
Menifee County
22%1.4 pCi/L2
McCracken County
21%1.6 pCi/L3
Edmonson County
21%1.6 pCi/L2
Perry County
21%1.4 pCi/L2
Bracken County5 tests––2
Clay County7 tests––2
Daviess County
20%1.8 pCi/L2
Breathitt County
19%1.7 pCi/L2
Rowan County
19%1.6 pCi/L2
Boyd County
18%2.1 pCi/L2
Todd County
18%1.8 pCi/L2
Muhlenberg County16 tests––2
Pike County
17%1.1 pCi/L2
Hancock County5 tests––2
Bell County7 tests––2
Greenup County
13%2.0 pCi/L2
Webster County7 tests––2
Ohio County16 tests––2
Marshall County
11%1.5 pCi/L3
Knox County
10%2.1 pCi/L2
Leslie County5 tests––2
Nicholas County17 tests––2
Hopkins County
10%1.7 pCi/L2
Graves County
8%1.5 pCi/L3
Lee County13 tests––2
Morgan County15 tests––2
Whitley County
4%1.6 pCi/L2
Butler County
4%1.5 pCi/L2
Ballard County4 tests––3
Carlisle County1 tests––3
Fulton County1 tests––3
Hickman County4 tests––3
Jackson County9 tests––2
Johnson County
0%0.8 pCi/L2
Lawrence County8 tests––2
Livingston County6 tests––2
Magoffin County8 tests––2
Martin County2 tests––2
McCreary County8 tests––2
Wolfe County4 tests––2

"–" means fewer than 20 tests or no lab data, too few for a reliable figure.

Sources

Last updated October 2026. How we calculate these numbers.