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Radon Levels in Roanoke County, Virginia

EPA puts Roanoke County in Zone 1, its highest radon zone, and 22.1% of its 1,541 reported radon tests (2008 to 2017, laboratory totals) were 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

    22.1%

    8.3 pts below VA

    Roanoke
    22.1%
    Virginia
    30.4%

    1,541 tests, 2008 to 2017

  • Median result

    1.9pCi/L

    Below action level

    Roanoke
    1.9 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    1,541

    9th of 84 by tests

    Roanoke
    1,541
    Fairfax
    8,657

    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 Virginia

    68 of 84

    Lowest quarter

    Roanoke
    22.1%
    Russell
    67.3%

    By share, of 84 with 30+ tests

Read a result for Roanoke County

Starts at Roanoke County's median, 1.9 pCi/L

1.9pCi/L

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

EPA’s reading of 1.9 pCi/L

Below 2 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 below 2 pCi/L, the level at which EPA says a fix should be considered. Roanoke County's median reported result, 2008 to 2017.

Interpret this reading

The data

Roanoke County, At a glance

Roanoke County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Roanoke 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: High across 65% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

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

Reported results by concentration band, Roanoke County, 2008 to 2017, laboratory
Under 2 pCi/L: 50%2 to 4 pCi/L: 28%4 pCi/L and above: 22%

Of 1,541 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Roanoke County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L77550.3%
2 to 4 pCi/L42627.6%
4 pCi/L and above34022.1%
What these figures count

These are the 1,541 tests reported to CDC for Roanoke 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

Roanoke County, Compared

Roanoke County radon figures, compared

Calculated by Radon411

Roanoke County's 1,541 reported tests over the 2008 to 2017 laboratory totals had a middle value of 1.9 pCi/L and a maximum of 37.4 pCi/L, and 22.1% reached 4 pCi/L. Virginia as a whole (131 Virginia counties, pooled) comes to 30.4%: 8.3 points higher than here.

Among its state's counties it ranks 68th of 84 Virginia counties with 30 or more tests for the same period. Statewide for the same period, Russell County reported the highest share (67.3%) and Norfolk city the lowest (2.7%).

Below the action level, 775 tests (50.3%) came in under 2 pCi/L, against 44.7% statewide, and 426 tests (27.6%) fell between 2 and 4, against 24.9% statewide. CDC's ten-year totals for Roanoke County went from 1,663 tests (2005 to 2014) to 1,541 (2008 to 2017), the share going from 19.8% to 22.1%.

EPA's 1993 zone map puts Roanoke County in Zone 1, a predicted county average above 4 pCi/L. USGS geology rates 65% of the county's land high radon potential.

Next door, the shares run from 21.2% in Franklin County to 42.6% in Floyd County, with Franklin County below Roanoke County.

CDC also counts 131 tests taken after mitigation in Roanoke County for the same period: tests in homes where a fix was already in.

Roanoke County against Virginia, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Roanoke County
Roanoke County1,54122.1%1.9 pCi/LThis county
Virginia, pooled131 counties, pooled53,19930.4%Not pooled+8.3 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+13.6 points
Russell Countyhighest in the state4967.3%6.7 pCi/L+45.2 points
Norfolk citylowest in the state732.7%0.5 pCi/L−19.4 points
Craig County, VAborders it1346.2%2.8 pCi/L+24.1 points
Floyd County, VAborders it5442.6%3.3 pCi/L+20.5 points
Botetourt County, VAborders it57542.1%3.3 pCi/L+20.0 points
Montgomery County, VAborders it97035.5%2.5 pCi/L+13.4 points
Salem city, VAborders it28633.6%2.8 pCi/L+11.5 points
Roanoke city, VAborders it1,01025.9%2.3 pCi/L+3.8 points
Bedford County, VAborders it74923.5%2.1 pCi/L+1.4 points
Franklin County, VAborders it57221.2%2.0 pCi/L−0.9 points
Where Roanoke County's reported results fell, 2008 to 2017, laboratory, beside Virginia and the United States
ResultRoanoke County testsRoanoke County shareVirginia shareU.S. shareAgainst Virginia
Under 2 pCi/L77550.3%44.7%39.6%+5.6 points
2 to 4 pCi/L42627.6%24.9%24.7%+2.7 points
4 pCi/L and above34022.1%30.4%35.7%−8.3 points
Roanoke County ranked among the 84 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
Roanoke city63 of 841,01025.9%2.3 pCi/L
Lynchburg city64 of 8475325.9%2.2 pCi/L
Albemarle County65 of 842,17924.7%2.1 pCi/L
Bedford County66 of 8474923.5%2.1 pCi/L
Hanover County67 of 8416523.0%1.9 pCi/L
Roanoke County68 of 841,54122.1%1.9 pCi/L
Franklin County69 of 8457221.2%2.0 pCi/L
Charlottesville city70 of 8483421.0%1.8 pCi/L
Halifax County71 of 843718.9%2.2 pCi/L
Lexington city72 of 843218.8%1.6 pCi/L
Fairfax County73 of 848,65718.7%1.5 pCi/L
Roanoke County ten-year laboratory totals, against Virginia's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestVirginia, pooledChange from the row before
2008 to 20171,54122.1%1.9 pCi/L37.4 pCi/L30.4%+0.7 points
2007 to 20161,54921.4%1.9 pCi/L37.4 pCi/L30.6%+1.0 points
2006 to 20151,62120.4%1.9 pCi/L37.4 pCi/L30.7%+0.6 points
2005 to 20141,66319.8%1.8 pCi/L30.1 pCi/L30.3%First on file

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

Roanoke County, Geology

The ground under Roanoke County

Predicted

USGS's geologic map splits Roanoke County: 65.4% of its land is high radon potential and 34.6% moderate. The map puts 65.4% of Roanoke County in the area it calls Valley and Ridge and 34.6% in Blue Ridge. USGS gives the first a radon index of 15, in the high band (12 to 17), and the second 10, in the moderate band (9 to 11).

USGS's geologic areas under Roanoke County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Valley and RidgeCambrian dolomite, limestone, shale, and sandstone, Silurian-Ordovician limestone, dolomite, shale, and sandstone, Mississippian-Devonian sandstone, shale, limestone, gypsum, and coal.High1565.4%
Blue RidgeGranite, pegmatite, monazite, schist, and gneiss.Moderate1034.6%

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

Roanoke County beside the ground around it

Roanoke County has more high-potential ground than Virginia as a whole: 65.4% of its land against 47.9%. Of the 8 counties that border it, 5 have more high-potential ground, Salem city the most at 100%.

Share of land by USGS radon potential: Roanoke County, the 8 counties bordering it and Virginia
AreaEPA zoneLow potentialModerate potentialHigh potential
Roanoke CountyZone 1None34.6%65.4%
Salem cityZone 1NoneNone100%
Roanoke cityZone 1None3.3%96.7%
Montgomery CountyZone 1None13.0%87.0%
Craig CountyZone 1NoneNone100%
Franklin CountyZone 2None77.0%23.0%
Floyd CountyZone 2None100%None
Botetourt CountyZone 1None6.5%93.5%
Bedford CountyZone 2None84.9%15.1%
Virginia133 counties, pooled by land areaVaries20.6%30.0%47.9%

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

Local help

Roanoke County, Local resources

Radon testing and mitigation in Roanoke County

What Virginia's program says
Phone
(804) 864-8161
Email
Radon@vdh.virginia.gov
Licensing of radon professionals
The Code of Virginia requires that Radon testers and mitigators be currently certified by either the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB).

What it means

Roanoke County, Questions

Questions about radon in Roanoke County

Are radon levels high in Roanoke County?

Over the 2008 to 2017 laboratory totals, 22.1% of the radon tests reported to CDC for Roanoke County, Virginia were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.9 pCi/L. Of 84 Virginia counties with 30 or more tests for the same period, 67 reported a higher share; pooled, the state comes to 30.4%.

Which counties border Roanoke County?

Roanoke County borders 8 counties: Salem city, Roanoke city, Montgomery County, Craig County, Franklin County, Floyd County, Botetourt County and Bedford County.

Products

Roanoke County, Products

Testing a home in Roanoke County

In Roanoke County, 22.1% of 1,541 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 30.4% pooled across Virginia. In Zone 1 the year-round level in Roanoke 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

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

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Roanoke County, Bordering counties

Counties bordering Roanoke County

Calculated by Radon411

Roanoke County, Cities and towns

Cities and towns in Roanoke County

Roanoke County's population has barely moved since 2020: 97,150 residents on July 1, 2025 against 96,958 then, by the Census Bureau's estimates. That works out to 388 people per square mile of land. Vinton, its one incorporated place, has 7,967 residents, 8.2% of the total. Testing is reported here more often than across the state: CDC's 1,541 reported tests for 2008 to 2017 come to 15.9 for every 1,000 residents (2025 estimate), against 6.0 for Virginia.

Vinton is the one incorporated place here; CDC publishes no figure by town, so it reads Roanoke County's.

Vinton, Roanoke County: residents on July 1, 2025
PlaceResidentsSince 2020Share of residents
Vinton7,967Level8.2%

One incorporated place, 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).

Roanoke County, Homes

Homes in Roanoke County

Of Roanoke County's 42,251 homes, 75% are detached houses, against 61% across Virginia; 15% are in buildings of five or more homes. Half of its homes were built before 1978, close to Virginia's 1984: 17% date from before 1960 and 18% from 2000 or later. Owners live in 76% of the occupied homes (Virginia: 67%), so for most households a test and a fix are their own to order.

Homes in Roanoke County, Virginia, 2019 to 2023
HomesRoanoke CountyVirginia
Housing units42,2513,654,784
Detached houses75%61%
In buildings of 5 or more15%19%
Mobile homes2%4%
Built before 196017%19%
Built since 200018%25%
Middle year built19781984
Owner-occupied76%67%

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