Radon in North Carolina

About 1 in 4 homes tested in North Carolina were at or above the EPA action level of 4 pCi/L.

43,945 homes tested, 2008–2017
  • Below 2 pCi/L: 56%
  • 2 to 4 pCi/L: 22%
  • 4 pCi/L or more: 23%
The line marks the EPA action level, 4 pCi/L.

The EPA puts 8 of North Carolina's 100 counties in Zone 1, its highest radon category, 31 in Zone 2 and 61 in Zone 3.

Every county in North Carolina

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
Transylvania County
48%3.7 pCi/L1
Watauga County
45%3.5 pCi/L1
Wilkes County
44%3.5 pCi/L2
Swain County
44%3.4 pCi/L2
Cherokee County
43%3.4 pCi/L1
Clay County
43%3.0 pCi/L2
Warren County
43%3.0 pCi/L2
Halifax County
42%2.6 pCi/L3
Graham County
42%3.0 pCi/L2
Henderson County
42%3.3 pCi/L1
Alleghany County
41%3.3 pCi/L1
Northampton County
40%3.4 pCi/L3
Cleveland County
40%2.8 pCi/L2
Avery County
39%2.8 pCi/L2
McDowell County
38%2.7 pCi/L2
Pasquotank County5 tests––3
Ashe County
34%2.5 pCi/L2
Surry County
33%2.4 pCi/L2
Alexander County
33%2.5 pCi/L2
Yancey County
31%1.9 pCi/L2
Haywood County
31%2.2 pCi/L2
Polk County
30%2.4 pCi/L2
Buncombe County
29%2.3 pCi/L1
Lincoln County
29%2.4 pCi/L2
Forsyth County
29%2.3 pCi/L2
Mitchell County
29%2.1 pCi/L1
Yadkin County
29%2.2 pCi/L2
Burke County
28%2.4 pCi/L2
Jackson County
28%2.2 pCi/L2
Caldwell County
28%2.5 pCi/L2
Rockingham County
27%2.1 pCi/L1
Dare County
27%0.1 pCi/L3
Rutherford County
26%2.4 pCi/L2
Davidson County
26%1.8 pCi/L3
Stanly County
25%2.2 pCi/L3
Bertie County3 tests––3
Catawba County
25%2.0 pCi/L2
Iredell County
22%1.8 pCi/L2
Stokes County
22%1.8 pCi/L2
Montgomery County
20%1.5 pCi/L3
Moore County
19%1.3 pCi/L3
Franklin County
19%1.4 pCi/L2
Gaston County
19%1.5 pCi/L2
Rowan County
18%1.4 pCi/L3
Davie County
17%1.7 pCi/L3
Person County
17%1.3 pCi/L3
Macon County
17%1.4 pCi/L2
Madison County
17%1.3 pCi/L2
Caswell County
15%1.6 pCi/L2
Vance County
15%1.5 pCi/L2
Pender County15 tests––3
Union County
11%1.1 pCi/L3
Chatham County
11%1.1 pCi/L3
Orange County
11%1.1 pCi/L3
Granville County
11%0.8 pCi/L3
Wake County
10%1.0 pCi/L2
Cabarrus County
9%1.0 pCi/L3
Mecklenburg County
9%0.9 pCi/L3
Johnston County
8%0.7 pCi/L3
Wayne County
8%0.6 pCi/L3
Guilford County
8%0.9 pCi/L3
Randolph County
7%0.9 pCi/L3
Durham County
4%0.7 pCi/L3
Robeson County
4%0.8 pCi/L3
Alamance County
4%0.5 pCi/L3
New Hanover County
3%0.1 pCi/L3
Scotland County
3%1.0 pCi/L3
Onslow County
3%0.5 pCi/L3
Cumberland County
2%0.7 pCi/L3
Lee County
1%0.9 pCi/L3
Pitt County
1%0.1 pCi/L3
Harnett County
1%0.6 pCi/L3
Anson County
0%0.6 pCi/L3
Beaufort County
0%0.1 pCi/L3
Bladen County12 tests––3
Brunswick County
0%0.5 pCi/L3
Carteret County
0%0.1 pCi/L3
Chowan County4 tests––3
Columbus County
0%0.1 pCi/L3
Craven County
0%0.2 pCi/L3
Currituck County6 tests––3
Duplin County5 tests––3
Edgecombe County8 tests––3
Gates County1 tests––3
Greene County7 tests––3
Hertford County2 tests––3
Hoke County18 tests––3
Hyde County4 tests––3
Jones County1 tests––3
Lenoir County13 tests––3
Martin County4 tests––3
Nash County
0%0.2 pCi/L3
Pamlico County1 tests––3
Perquimans County4 tests––3
Richmond County
0%0.6 pCi/L3
Sampson County11 tests––3
Tyrrell County1 tests––3
Washington County1 tests––3
Wilson County17 tests––3
Camden CountyNo data––3

"–" 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.