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North Carolina Radon Map and Levels by County

North Carolina's counties span all three EPA radon zones. Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

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  • Share at 4+ pCi/L

    22.6%

    13.1 pts below U.S.

    North Carolina
    22.6%
    U.S.
    35.7%

    73,139 tests across 99 counties, 2008 to 2017

  • Rank among states

    36 of 47

    Middle of the states

    North Carolina
    22.6%
    North Dakota
    59.3%

    By share, every state pooled the same way, 2008 to 2017

  • Counties in EPA Zone 1

    8 of 100

    Some at highest potential

    Zone 1
    8
    Zone 2
    31

    Most counties sit in Zone 3; Zone 1 is the highest potential

  • Highest county

    47.8%

    Transylvania County

    Transylvania
    47.8%
    Nash
    0.0%

    Counties with 30+ tests, 2008 to 2017

Read a result for North Carolina

Starts at EPA's action level

4.0pCi/L

EPA’s own thresholds; the figures are the area’s, never this home’s.

EPA’s reading of 4.0 pCi/L

At or above 4 pCi/L

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 4 and aboveEPA says fix it

This result is at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. 22.6% of North Carolina's reported tests reached 4 pCi/L, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

North Carolina, At a glance

North Carolina at a glance

Predicted: EPA radon zone

100 of 100 counties classified

EPA classifies counties, not states. Of the 100 counties in North Carolina with a zone, 8 are in Zone 1, 31 in Zone 2 and 61 in Zone 3.

  • Zone 1: Highest predicted potentialgreater than 4 pCi/L8 of 100 counties · 8.0%
  • Zone 2: Moderate predicted potential2 to 4 pCi/L31 of 100 counties · 31.0%
  • Zone 3: Lower predicted potentialless than 2 pCi/L61 of 100 counties · 61.0%

An EPA radon zone predicts a whole county. It is not intended to determine whether any individual home should be tested: homes with elevated levels occur in all three zones, and EPA recommends testing every home regardless of zone.

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

CDC test figures, county by county

CDC publishes North Carolina's radon test figures by county: 100 of its 100 counties have one. Each one's share is in the county list.

How to read these figures

North Carolina, Compared

North Carolina radon figures, compared

Calculated by Radon411
North Carolina, 2008 to 2017, laboratory
22.6%
of 73,139 tests at or above 4 pCi/L, pooled
Against the U.S.
−13.1points
35.7% pooled
Rank among the states
36 of 47
1 is the highest share
Counties with 30 or more tests
75
Highest
47.8%
Transylvania County
Lowest
0.0%
Nash County

About 2 in 10 of the 73,139 tests reported for North Carolina over the 2008 to 2017 laboratory totals came back at or above 4 pCi/L (22.6%, 99 counties pooled). That is 36th of 47 states with county figures for the period; Florida (22.7%) above it and Alabama (21.9%) below.

By band, 20 counties at 30% to 50%, 26 counties at 15% to 30%, 13 counties at 5% to 15%, 16 counties at under 5%. Its 75 counties with 30 or more tests run from 0.0% in Nash County to 47.8% in Transylvania County; in 0 of them half or more of the reported tests reached 4 pCi/L.

EPA's 1993 map puts 8 of its 100 classified counties in Zone 1; the tests reported since bear that out at 22.6%. The national pool for the same period is 35.7%, so North Carolina runs 13.1 points below the country.

Across its 4 overlapping ten-year totals, the share went from 24.0% (2005 to 2014) to 22.6% (2008 to 2017), within 2 points, with 2006 to 2015 the highest at 24.1%.

North Carolina ranked among 47 states by pooled share of tests at or above 4 pCi/L, 2008 to 2017, laboratory
StateRankCountiesTestsAt or above 4 pCi/L
Massachusetts31 of 4714234,15223.8%
Rhode Island32 of 47537,87423.8%
Arkansas33 of 475866823.2%
Nevada34 of 471610,93022.8%
Florida35 of 476253,79422.7%
North Carolina36 of 479973,13922.6%
Alabama37 of 476512,56921.9%
Vermont38 of 471410,60021.7%
South Carolina39 of 474626,48119.4%
Alaska40 of 47983018.2%
Arizona41 of 47133,58916.8%
North Carolina's highest and lowest counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/L
Transylvania County1 of 753,86247.8%
Watauga County2 of 751,21545.1%
Wilkes County3 of 7540244.3%
Swain County4 of 7511644.0%
Cherokee County5 of 751,04543.2%
Clay County6 of 7532343.0%
Warren County7 of 758242.7%
Halifax County8 of 755942.4%
Graham County9 of 756942.0%
Henderson County10 of 754,09341.8%
Nash County75 of 75300.0%
Columbus County74 of 75310.0%
Carteret County73 of 75410.0%
Richmond County72 of 75520.0%
Brunswick County71 of 75620.0%
North Carolina's counties with 30 or more tests, by their own share at or above 4 pCi/L, 2008 to 2017, laboratory
ShareCountiesTheir testsFor example
50% or more00None
30% to 50%2017,069Transylvania County, Watauga County, Wilkes County
15% to 30%2627,362Polk County, Buncombe County, Lincoln County
5% to 15%1325,163Caswell County, Vance County, Union County
Under 5%163,339Durham County, Robeson County, Alamance County
North Carolina ten-year laboratory totals, pooled, against the United States
PeriodCountiesTestsAt or above 4 pCi/LUnited StatesChange from the row before
2008 to 20179973,13922.6%35.7%−0.6 points
2007 to 20169970,56623.2%35.8%−0.9 points
2006 to 20159764,90224.1%36.3%+0.1 points
2005 to 20149659,04324.0%36.0%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period. CDC publishes no state or national figure.

North Carolina, Counties

North Carolina counties by EPA zone

Predicted

The map of North Carolina, then its 100 counties zone by zone, each with its reported share at or above 4 pCi/L and a report of its own.

North Carolina radon map by county: EPA radon zones. Map of North Carolina's 100 counties shaded by EPA radon zone: Zone 1 in red-orange, Zone 2 in amber, Zone 3 in pale sand. 8 in Zone 1, 31 in Zone 2, 61 in Zone 3.
North Carolina radon map by countyEPA radon zones for North Carolina's counties: 8 counties in Zone 1, 31 counties in Zone 2, 61 counties in Zone 3.A prediction for each county, not a reading of any home; elevated homes occur in all three zones.

The 12 highest in North Carolina, 2008 to 2017

Zone 1: highest predicted potential8

Local help

North Carolina, Local resources

Local resources in North Carolina

Who to ask in North Carolina: its radon program, test kits and professionals.

What North Carolina's program says
Licensing of radon professionals
The North Carolina Radon Program is presently developing a Radon Proficiency Program as directed by Session Law 2023-91 House Bill 782 .

What it means

North Carolina, Questions

Questions about radon in North Carolina

Is radon a problem in North Carolina?

North Carolina has 100 counties on EPA's Map of Radon Zones: Zone 1, the highest predicted potential, for 8; Zone 2 for 31; Zone 3 for 61. Pooled from 99 counties, 22.6% of the 73,139 radon tests reported to CDC over the 2008 to 2017 laboratory totals were at or above 4 pCi/L, 36th of 47 states.

Which North Carolina counties are in EPA radon Zone 1?

8 counties are in Zone 1: Alleghany County, Buncombe County, Cherokee County, Henderson County, Mitchell County, Rockingham County, Transylvania County, Watauga County.

Who does radon mitigation in North Carolina?

Radon411's North Carolina directory lists 2 radon businesses for testing, mitigation or both, each with the licensing list it was read from.

Which North Carolina counties have the highest radon?

By the share of reported tests at or above 4 pCi/L, 2008 to 2017, laboratory: Transylvania County 47.8% (3,862 tests), Watauga County 45.1% (1,215 tests), Wilkes County 44.3% (402 tests), Swain County 44.0% (116 tests), Cherokee County 43.2% (1,045 tests).

Which EPA region is North Carolina in?

North Carolina is in EPA Region 4: Southeast.

Products

North Carolina, Products

Testing a home in North Carolina

22.6% of the 73,139 tests reported to CDC for North Carolina over the 2008 to 2017 laboratory totals reached 4 pCi/L: a short-term kit (2 to 90 days) gives a first answer in days, a long-term test the year-round average. A short-term kit (2 to 90 days) is the quick first check for a home in North Carolina; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for North Carolina homes, compared

Explore

Cities in North Carolina with their own page

Radon data is published by county, not by city. Each city page sets the figures of the counties the city lies in side by side.