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Radon Levels in Grayson County, Kentucky

EPA puts Grayson County in Zone 2, its middle radon zone, and 27.8% of its 36 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

    27.8%

    15.9 pts below KY

    Grayson
    27.8%
    Kentucky
    43.7%

    36 tests, 2008 to 2017

  • Median result

    2.2pCi/L

    Below action level

    Grayson
    2.2 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    36

    62nd of 69 by tests

    Grayson
    36
    Jefferson
    6,590

    Reported to CDC before any fix, 2008 to 2017

  • EPA radon zone

    Zone 2

    Moderate potential

    1. 1
    2. Zone 2
    3. 3

    1 highest, 3 lowest

    EPA predicts 2 to 4 pCi/L indoors

  • Rank in Kentucky

    48 of 69

    Middle half

    Grayson
    27.8%
    Meade
    68.4%

    By share, of 69 with 30+ tests

Read a result for Grayson County

Starts at Grayson County's median, 2.2 pCi/L

2.2pCi/L

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

EPA’s reading of 2.2 pCi/L

Between 2 and 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 between 2 and 4 pCi/L. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Grayson County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Grayson County, At a glance

Grayson County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Grayson County is a county: EPA's forecast for it as a whole is an average indoor of 2 to 4 pCi/L (75 to 150 Bq/m³). It describes no single address, and homes above EPA's are found in every zone, this one included.

USGS geologic potential: Moderate across 100% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

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

Reported results by concentration band, Grayson County, 2008 to 2017, laboratory
Under 2 pCi/L: 39%2 to 4 pCi/L: 33%4 pCi/L and above: 28%

Of 36 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Grayson County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L1438.9%
2 to 4 pCi/L1233.3%
4 pCi/L and above1027.8%
What these figures count

These are the 36 tests reported to CDC for Grayson 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

Grayson County, Compared

Grayson County radon figures, compared

Calculated by Radon411

Grayson County's 36 reported tests over the 2008 to 2017 laboratory totals had a middle value of 2.2 pCi/L and a maximum of 15.7 pCi/L, and 27.8% reached 4 pCi/L. Kentucky as a whole (120 Kentucky counties, pooled) comes to 43.7%: 15.9 points higher than here.

Among its state's counties it ranks 48th of 69 Kentucky counties with 30 or more tests for the same period. Statewide for the same period, Meade County reported the highest share (68.4%) and Hopkins County the lowest (9.5%).

Below the action level, 14 tests (38.9%) came in under 2 pCi/L, against 33.2% statewide, and 12 tests (33.3%) fell between 2 and 4, against 23.1% statewide. CDC's ten-year totals for Grayson County went from 32 tests (2005 to 2014) to 36 (2008 to 2017), the share going from 25.0% to 27.8%.

EPA's 1993 zone map puts Grayson County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 100% of the county's land moderate radon potential.

Next door, the shares run from 21.0% in Edmonson County to 65.5% in Hart County, with Edmonson County below Grayson County.

Grayson County against Kentucky, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Grayson County
Grayson County3627.8%2.2 pCi/LThis county
Kentucky, pooled120 counties, pooled28,79343.7%Not pooled+15.9 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+7.9 points
Meade Countyhighest in the state11768.4%8.2 pCi/L+40.6 points
Hopkins Countylowest in the state429.5%1.7 pCi/L−18.3 points
Hart County, KYborders it8465.5%8.0 pCi/L+37.7 points
Hardin County, KYborders it42950.3%4.0 pCi/L+22.5 points
Breckinridge County, KYborders it3231.3%2.5 pCi/L+3.5 points
Edmonson County, KYborders it6221.0%1.6 pCi/L−6.8 points
Ohio County, KYborders it1711.8%1.9 pCi/L−16.0 points
Butler County, KYborders it263.8%1.5 pCi/L−24.0 points
Where Grayson County's reported results fell, 2008 to 2017, laboratory, beside Kentucky and the United States
ResultGrayson County testsGrayson County shareKentucky shareU.S. shareAgainst Kentucky
Under 2 pCi/L1438.9%33.2%39.6%+5.7 points
2 to 4 pCi/L1233.3%23.1%24.7%+10.2 points
4 pCi/L and above1027.8%43.7%35.7%−15.9 points
Grayson County ranked among the 69 Kentucky counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Logan County43 of 697931.6%2.4 pCi/L
Spencer County44 of 6916631.3%2.5 pCi/L
Breckinridge County45 of 693231.3%2.5 pCi/L
Allen County46 of 695829.3%1.9 pCi/L
Clark County47 of 6923129.0%2.4 pCi/L
Grayson County48 of 693627.8%2.2 pCi/L
Washington County49 of 694427.3%2.4 pCi/L
Pendleton County50 of 693426.5%1.9 pCi/L
Campbell County51 of 6954326.2%2.3 pCi/L
Kenton County52 of 691,16726.0%2.3 pCi/L
Anderson County53 of 6922625.2%2.2 pCi/L
Grayson County ten-year laboratory totals, against Kentucky's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestKentucky, pooledChange from the row before
2008 to 20173627.8%2.2 pCi/L15.7 pCi/L43.7%+1.3 points
2007 to 20163426.5%2.2 pCi/L14.4 pCi/L45.1%Level
2006 to 20153426.5%2.1 pCi/L14.4 pCi/L46.4%+1.5 points
2005 to 20143225.0%2.0 pCi/L14.4 pCi/L47.3%First on file

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

Grayson County, Geology

The ground under Grayson County

Predicted

USGS's geologic map puts all of Grayson County's mapped land in one class: moderate radon potential. The map puts 74.8% of Grayson County in the area it calls Mississippian Plateau and 25.2% in Western Coalfield. USGS gives the first a radon index of 11 and the second 9, both in the moderate band (9 to 11).

USGS's geologic areas under Grayson County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Mississippian PlateauMississippian marine limestones, dolomites, marine sandstones, siltstones, and shales.Moderate1174.8%
Western CoalfieldLimestones, shale, siltstone, and coal beds.Moderate925.2%

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

Grayson County beside the ground around it

Across Kentucky 18.2% of the land is rated high; none of Grayson County's is. Of the 6 counties that border it, 1 has more high-potential ground, Hardin County the most at 3.4%.

Share of land by USGS radon potential: Grayson County, the 6 counties bordering it and Kentucky
AreaEPA zoneLow potentialModerate potentialHigh potential
Grayson CountyZone 2None100%None
Edmonson CountyZone 2None100%None
Breckinridge CountyZone 2None100%None
Butler CountyZone 2None100%None
Hardin CountyZone 2None96.6%3.4%
Hart CountyZone 1None100%None
Ohio CountyZone 2None100%None
Kentucky120 counties, pooled by land areaVaries5.7%76.1%18.2%

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

Local help

Grayson County, Local resources

Radon testing and mitigation in Grayson County

What Kentucky's program says
Phone
502-782-2782
Email
Radon@ky.gov

What it means

Grayson County, Questions

Questions about radon in Grayson County

Are radon levels high in Grayson County?

Over the 2008 to 2017 laboratory totals, 27.8% of the radon tests reported to CDC for Grayson County, Kentucky were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.2 pCi/L. Of 69 Kentucky counties with 30 or more tests for the same period, 47 reported a higher share; pooled, the state comes to 43.7%.

Which counties border Grayson County?

Grayson County borders 6 counties: Edmonson County, Breckinridge County, Butler County, Hardin County, Hart County and Ohio County.

Products

Grayson County, Products

Testing a home in Grayson County

In Grayson County, 27.8% of 36 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 43.7% pooled across Kentucky. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Grayson County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Grayson County homes, compared

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Grayson County, Bordering counties

Counties bordering Grayson County

Calculated by Radon411

Grayson County, Cities and towns

Cities and towns in Grayson County

The Census Bureau estimates 27,406 residents in Grayson County for July 1, 2025, 948 more than in 2020 (+3.6%). That works out to 55 people per square mile of land. Its largest town, Leitchfield, has 7,015 residents, 25.6% of the total. Together its 3 incorporated places hold 31.2% of those residents; the other 68.8% live outside any of them. Reported testing is thin here: 36 tests over 2008 to 2017, or 1.3 for every 1,000 residents (2025 estimate), where Kentucky as a whole comes to 6.3.

From Leitchfield to Caneyville, CDC publishes no figure by town: each reads Grayson County's.

The cities and towns in Grayson County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Leitchfield7,015+3.4%25.6%
Clarkson972+3.6%3.5%
Caneyville550+3.8%2.0%

3 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).

Grayson County, Homes

Homes in Grayson County

Of Grayson County's 13,336 homes, 73% are detached houses, against 68% across Kentucky; 18% are mobile homes. Half of its homes were built before 1988, close to Kentucky's 1982: 11% date from before 1960 and 31% from 2000 or later. Owners live in 76% of the occupied homes (Kentucky: 68%), so for most households a test and a fix are their own to order.

Homes in Grayson County, Kentucky, 2019 to 2023
HomesGrayson CountyKentucky
Housing units13,3362,010,655
Detached houses73%68%
In buildings of 5 or more3%12%
Mobile homes18%11%
Built before 196011%22%
Built since 200031%24%
Middle year built19881982
Owner-occupied76%68%

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