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Radon Levels in Greenbrier County, West Virginia

EPA puts Greenbrier County in Zone 1, its highest radon zone, and high results are common there: 52.3% of the 176 radon tests reported to CDC (2008 to 2017, laboratory totals) came back at or above 4 pCi/L. 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

    52.3%

    14.8 pts above WV

    Greenbrier
    52.3%
    WV
    37.5%

    176 tests, 2008 to 2017

  • Median result

    4.5pCi/L

    Action level reached

    Greenbrier
    4.5 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    176

    12th of 27 by tests

    Greenbrier
    176
    Berkeley
    2,888

    Reported to CDC before any fix, 2008 to 2017

  • EPA radon zone

    Zone 1

    Highest potential

    1. Zone 1
    2. 2
    3. 3

    1 highest, 3 lowest

    EPA predicts over 4 pCi/L indoors

  • Rank in WV

    3 of 27

    Top quarter

    Greenbrier
    52.3%
    Morgan
    58.1%

    By share, of 27 with 30+ tests

Read a result for Greenbrier County

Starts at Greenbrier County's median, 4.5 pCi/L

4.5pCi/L

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

EPA’s reading of 4.5 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. Greenbrier County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Greenbrier County, At a glance

Greenbrier County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Greenbrier County in and predicts an average indoor of greater than 4 pCi/L (greater than 150 Bq/m³) across the county. That is one forecast for the whole county, not a reading of any address in it; homes above EPA's turn up in all three zones.

USGS geologic potential: Moderate across 76% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Greenbrier County, 2008 to 2017, laboratory

Reported results by concentration band, Greenbrier County, 2008 to 2017, laboratory
Under 2 pCi/L: 31%2 to 4 pCi/L: 17%4 pCi/L and above: 52%

Of 176 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Greenbrier County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L5430.7%
2 to 4 pCi/L3017.0%
4 pCi/L and above9252.3%
What these figures count

These are the 176 tests reported to CDC for Greenbrier County over 2008 to 2017 (laboratory totals), many from homes being sold or already suspected of a problem: they describe the county's reported tests, not this house.

Measured: CDC tracking data. Figure above: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).

How to read these figures

Greenbrier County, Compared

Greenbrier County radon figures, compared

Calculated by Radon411

More than half: 52.3% of the 176 radon tests reported to CDC for Greenbrier County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 3rd of 27 West Virginia counties with 30 or more tests for the same period. That is 14.8 points above the 37.5% pooled from 55 West Virginia counties.

The median result, 4.5 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 129.7 pCi/L. The rest split 30.7% under 2 pCi/L and 17.0% from 2 to 4 (West Virginia: 37.7% and 24.7%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 52.3% share point the same way here.

Alleghany County, VA, the one bordering county with a figure for the same period, reported 40.0%. Statewide for the same period, Morgan County reported the highest share (58.1%) and Grant County the lowest (9.8%).

CDC's ten-year totals for Greenbrier County went from 206 tests (2005 to 2014) to 176 (2008 to 2017), the share going from 43.7% to 52.3%.

Nationally, every county with a figure for the same period pools to 35.7%; Greenbrier County sits 16.6 points above it. CDC also counts 35 tests taken after mitigation in Greenbrier County for the same period: tests in homes where a fix was already in.

Greenbrier County against West Virginia, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Greenbrier County
Greenbrier County17652.3%4.5 pCi/LThis county
West Virginia, pooled55 counties, pooled10,06137.5%Not pooled−14.8 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−16.6 points
Morgan Countyhighest in the state24158.1%5.8 pCi/L+5.8 points
Grant Countylowest in the state1649.8%1.1 pCi/L−42.5 points
Alleghany County, VAborders it5040.0%3.0 pCi/L−12.3 points
Monroe County, WVborders it1833.3%3.6 pCi/L−19.0 points
Nicholas County, WVborders it1330.8%2.6 pCi/L−21.5 points
Webster County, WVborders it1421.4%1.3 pCi/L−30.9 points
Bath County, VAborders it2218.2%2.3 pCi/L−34.1 points
Summers County, WVborders it1513.3%1.5 pCi/L−39.0 points
Pocahontas County, WVborders it1612.5%1.0 pCi/L−39.8 points
Fayette County, WVborders it200.0%0.8 pCi/L−52.3 points
Where Greenbrier County's reported results fell, 2008 to 2017, laboratory, beside West Virginia and the United States
ResultGreenbrier County testsGreenbrier County shareWest Virginia shareU.S. shareAgainst West Virginia
Under 2 pCi/L5430.7%37.7%39.6%−7.0 points
2 to 4 pCi/L3017.0%24.7%24.7%−7.7 points
4 pCi/L and above9252.3%37.5%35.7%+14.8 points
Greenbrier County ranked among the 27 West Virginia counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Morgan County1 of 2724158.1%5.8 pCi/L
Jefferson County2 of 2789853.2%4.4 pCi/L
Greenbrier County3 of 2717652.3%4.5 pCi/L
Berkeley County4 of 272,88850.7%4.0 pCi/L
Hancock County5 of 2732649.1%3.9 pCi/L
Brooke County6 of 2715743.9%3.4 pCi/L
Mineral County7 of 2710742.1%2.8 pCi/L
Ohio County8 of 2785340.3%3.2 pCi/L
Hampshire County9 of 279038.9%2.8 pCi/L
Preston County10 of 2717636.9%2.5 pCi/L
Harrison County11 of 2718736.4%2.6 pCi/L
Greenbrier County ten-year laboratory totals, against West Virginia's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestWest Virginia, pooledChange from the row before
2008 to 201717652.3%4.5 pCi/L129.7 pCi/L37.5%+2.8 points
2007 to 201618649.5%3.8 pCi/L129.7 pCi/L37.3%−1.0 points
2006 to 201519050.5%4.2 pCi/L129.7 pCi/L37.7%+6.8 points
2005 to 201420643.7%3.2 pCi/L71.7 pCi/L37.3%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period.

Greenbrier County, Geology

The ground under Greenbrier County

Predicted

Most of the ground under Greenbrier County is one class on USGS's geologic map: 76.5% of its land is moderate radon potential, with 23.5% high. The map puts 64.0% of Greenbrier County in the area it calls Southern Appalachian Valley and Ridge and 23.2% in Northern Appalachian Valley and Ridge, with one smaller area beside them. USGS gives the first a radon index of 11, in the moderate band (9 to 11), and the second 14, in the high band (12 to 17).

USGS's geologic areas under Greenbrier County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Southern Appalachian Valley and RidgeOrdovician-Mississippian shale, siltstone, sandstone, limestone.Moderate1164.0%
Northern Appalachian Valley and RidgeSandstone ridges, shale and limestone valleys, mostly DevonianHigh1423.2%
Eastern Allegheny Plateau and MtnsDevonian-Pennsylvanian shale, siltstone, sandstone, minor limestone and coalModerate1012.5%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

Greenbrier County beside the ground around it

On high-potential ground Greenbrier County is close to West Virginia as a whole: 23.5% of its land against 18.7%. Of the 8 counties that border it, 4 have more high-potential ground, Bath County, VA the most at 100%.

Share of land by USGS radon potential: Greenbrier County, the 8 counties bordering it and West Virginia
AreaEPA zoneLow potentialModerate potentialHigh potential
Greenbrier CountyZone 1None76.5%23.5%
Alleghany County, VAZone 1NoneNone100%
Monroe CountyZone 1None54.8%45.2%
Summers CountyZone 1None100%None
Nicholas CountyZone 210.3%89.7%None
Webster CountyZone 2None100%None
Bath County, VAZone 1NoneNone100%
Pocahontas CountyZone 1None53.3%46.7%
Fayette CountyZone 232.5%67.5%None
West Virginia55 counties, pooled by land areaVaries14.0%67.3%18.7%

The map rates the ground, not the air in any home.

Local help

Greenbrier County, Local resources

Radon testing and mitigation in Greenbrier County

What West Virginia's program says
Phone
304-352-5039
Email
Radon@wv.gov
Licensing of radon professionals
Complete listings of professionals licensed to perform Asbestos, Lead, Radon and Clandestine Drug Laboratory Remediation activities in West Virginia.

What it means

Greenbrier County, Questions

Questions about radon in Greenbrier County

Are radon levels high in Greenbrier County?

Over the 2008 to 2017 laboratory totals, 52.3% of the radon tests reported to CDC for Greenbrier County, West Virginia were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.5 pCi/L. Of 27 West Virginia counties with 30 or more tests for the same period, 2 reported a higher share; pooled, the state comes to 37.5%.

Which counties border Greenbrier County?

Greenbrier County borders 8 counties: Alleghany County, VA, Monroe County, WV, Summers County, WV, Nicholas County, WV, Webster County, WV, Bath County, VA, Pocahontas County, WV and Fayette County, WV.

Products

Greenbrier County, Products

Testing a home in Greenbrier County

In Greenbrier County, 52.3% of 176 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 37.5% pooled across West Virginia. In Zone 1 the year-round level in Greenbrier County is the one to know: a long-term test (more than 90 days) or a monitor, with a short-term kit for a first answer.

Test kits and monitors3

See every kit and monitor

Greenbrier County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Greenbrier County

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Greenbrier County, Bordering counties

Counties bordering Greenbrier County

Calculated by Radon411

Greenbrier County, Cities and towns

Cities and towns in Greenbrier County

About 31,578 people live in Greenbrier County by the Census Bureau's estimate for July 1, 2025, 1,328 fewer than in 2020 (−4.0%). That works out to 31 people per square mile of land. No town dominates: Lewisburg, the largest, has 3,721 residents, 11.8% of the total. CDC's 176 reported tests for 2008 to 2017 work out to 5.6 per 1,000 residents (2025 estimate), close to West Virginia's 5.7.

From Lewisburg to Falling Spring, CDC publishes no figure by town: each reads Greenbrier County's.

The cities and towns in Greenbrier County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Lewisburg3,721−5.1%11.8%
White Sulphur Springs2,133−3.9%6.8%
Ronceverte1,492−4.8%4.7%
Rainelle1,180−4.6%3.7%
Aldersonextends beyond Greenbrier County925−4.5%Counted whole
Rupert822−5.7%2.6%
Quinwood204−7.3%0.6%
Falling Spring165−3.5%0.5%

8 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025). A place that extends beyond Greenbrier County is counted whole, so it has no share.

Greenbrier County, Homes

Homes in Greenbrier County

Of Greenbrier County's 17,883 homes, 74% are detached houses, against 71% across West Virginia; 14% are mobile homes. Half of its homes were built before 1977, close to West Virginia's 1976: 29% date from before 1960 and 18% from 2000 or later. 74% of occupied homes are lived in by their owner (West Virginia: 74%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Greenbrier County, West Virginia, 2019 to 2023
HomesGreenbrier CountyWest Virginia
Housing units17,883859,653
Detached houses74%71%
In buildings of 5 or more7%8%
Mobile homes14%14%
Built before 196029%33%
Built since 200018%18%
Middle year built19771976
Owner-occupied74%74%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.