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Radon Levels in Adair County, Kentucky

EPA puts Adair County in Zone 1, its highest radon zone, and high results are common there: 43.4% of the 53 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

    43.4%

    0.3 pts below KY

    Adair
    43.4%
    Kentucky
    43.7%

    53 tests, 2008 to 2017

  • Median result

    3.8pCi/L

    Below action level

    Adair
    3.8 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    53

    52nd of 69 by tests

    Adair
    53
    Jefferson
    6,590

    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 Kentucky

    25 of 69

    Middle half

    Adair
    43.4%
    Meade
    68.4%

    By share, of 69 with 30+ tests

Read a result for Adair County

Starts at Adair County's median, 3.8 pCi/L

3.8pCi/L

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

EPA’s reading of 3.8 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. Adair County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Adair County, At a glance

Adair County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Adair 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 100% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

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

Reported results by concentration band, Adair County, 2008 to 2017, laboratory
Under 2 pCi/L: 30%2 to 4 pCi/L: 27%4 pCi/L and above: 43%

Of 53 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Adair County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L1630.2%
2 to 4 pCi/L1426.4%
4 pCi/L and above2343.4%
What these figures count

These are the 53 tests reported to CDC for Adair 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

Adair County, Compared

Adair County radon figures, compared

Calculated by Radon411

In Adair County, about 4 in 10 reported tests over the 2008 to 2017 laboratory totals (23 of 53) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 7.7 points higher. Across 120 Kentucky counties pooled together, 43.7% of tests reached that level, so Adair County runs 0.3 points below its state.

Of 5 neighbours with a figure, 2 reported a larger share at or above 4 pCi/L and 3 a smaller one; the spread is 25.0% (Russell County) to 57.1% (Taylor County). By share, Adair County is 25th of 69 Kentucky counties with 30 or more tests for the same period.

Half the tests came in under 3.8 pCi/L and half over it; the single highest reached 33.3 pCi/L. Below the action level, 16 tests (30.2%) came in under 2 pCi/L, against 33.2% statewide, and 14 tests (26.4%) fell between 2 and 4, against 23.1% statewide.

Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 43.4% share point the same way here. USGS geology rates 100% of the county's land high radon potential.

CDC's ten-year totals for Adair County went from 66 tests (2005 to 2014) to 53 (2008 to 2017), the share going from 48.5% to 43.4%.

Adair County against Kentucky, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Adair County
Adair County5343.4%3.8 pCi/LThis county
Kentucky, pooled120 counties, pooled28,79343.7%Not pooled+0.3 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−7.7 points
Meade Countyhighest in the state11768.4%8.2 pCi/L+25.0 points
Hopkins Countylowest in the state429.5%1.7 pCi/L−33.9 points
Taylor County, KYborders it9157.1%4.4 pCi/L+13.7 points
Cumberland County, KYborders it1855.6%4.6 pCi/L+12.2 points
Metcalfe County, KYborders it3345.5%3.5 pCi/L+2.1 points
Casey County, KYborders it4332.6%3.1 pCi/L−10.8 points
Green County, KYborders it3132.3%2.5 pCi/L−11.1 points
Russell County, KYborders it3225.0%2.9 pCi/L−18.4 points
Where Adair County's reported results fell, 2008 to 2017, laboratory, beside Kentucky and the United States
ResultAdair County testsAdair County shareKentucky shareU.S. shareAgainst Kentucky
Under 2 pCi/L1630.2%33.2%39.6%−3.0 points
2 to 4 pCi/L1426.4%23.1%24.7%+3.3 points
4 pCi/L and above2343.4%43.7%35.7%−0.3 points
Adair 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
Larue County20 of 693447.1%3.7 pCi/L
Scott County21 of 6987546.9%3.6 pCi/L
Harrison County22 of 6911146.8%3.4 pCi/L
Metcalfe County23 of 693345.5%3.5 pCi/L
Estill County24 of 6917744.1%3.2 pCi/L
Adair County25 of 695343.4%3.8 pCi/L
Franklin County26 of 6981043.1%3.3 pCi/L
Boone County27 of 691,43442.9%3.5 pCi/L
Garrard County28 of 6916439.6%2.6 pCi/L
Jefferson County29 of 696,59039.4%2.7 pCi/L
Madison County30 of 6960438.7%2.9 pCi/L
Adair County ten-year laboratory totals, against Kentucky's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestKentucky, pooledChange from the row before
2008 to 20175343.4%3.8 pCi/L33.3 pCi/L43.7%+0.8 points
2007 to 20166142.6%3.7 pCi/L33.3 pCi/L45.1%−4.3 points
2006 to 20156446.9%3.8 pCi/L33.3 pCi/L46.4%−1.6 points
2005 to 20146648.5%3.9 pCi/L33.3 pCi/L47.3%First on file

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

Adair County, Geology

The ground under Adair County

Predicted

USGS's geologic map puts all of Adair County's mapped land in one class: high radon potential. All of it lies in the area the map calls Eastern Pennyroyal, to which USGS gives a radon index of 12, in the high band (12 to 17).

USGS's geologic areas under Adair County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Eastern PennyroyalMarine shale, sandstone and limestone.High12100%

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

Adair County beside the ground around it

Adair County has more high-potential ground than Kentucky as a whole: 100% of its land against 18.2%. Of the 6 counties that border it, none has as large a share of high-potential ground; Russell County comes nearest at 100%.

Share of land by USGS radon potential: Adair County, the 6 counties bordering it and Kentucky
AreaEPA zoneLow potentialModerate potentialHigh potential
Adair CountyZone 1NoneNone100%
Taylor CountyZone 1None13.6%86.4%
Russell CountyZone 1NoneNone100%
Green CountyZone 1None33.4%66.5%
Metcalfe CountyZone 1None22.6%77.4%
Casey CountyZone 1NoneNone100%
Cumberland CountyZone 1None13.6%86.4%
Kentucky120 counties, pooled by land areaVaries5.7%76.1%18.2%

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

Local help

Adair County, Local resources

Radon testing and mitigation in Adair County

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

What it means

Adair County, Questions

Questions about radon in Adair County

Are radon levels high in Adair County?

Over the 2008 to 2017 laboratory totals, 43.4% of the radon tests reported to CDC for Adair County, Kentucky were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.8 pCi/L. Of 69 Kentucky counties with 30 or more tests for the same period, 24 reported a higher share; pooled, the state comes to 43.7%.

Which counties border Adair County?

Adair County borders 6 counties: Taylor County, Russell County, Green County, Metcalfe County, Casey County and Cumberland County.

Products

Adair County, Products

Testing a home in Adair County

In Adair County, 43.4% of 53 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 43.7% pooled across Kentucky. In Zone 1 the year-round level in Adair 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

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

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Adair County, Bordering counties

Counties bordering Adair County

Calculated by Radon411

Adair County, Cities and towns

Cities and towns in Adair County

The Census Bureau estimates 19,423 residents in Adair County for July 1, 2025, 538 more than in 2020 (+2.8%). That works out to 48 people per square mile of land. Columbia, its one incorporated place, has 4,680 residents, 24.1% of the total. Reported testing is thin here: 53 tests over 2008 to 2017, or 2.7 for every 1,000 residents (2025 estimate), where Kentucky as a whole comes to 6.3.

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

Columbia, Adair County: residents on July 1, 2025
PlaceResidentsSince 2020Share of residents
Columbia4,680−3.2%24.1%

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).

Adair County, Homes

Homes in Adair County

Of Adair County's 8,632 homes, 74% are detached houses, against 68% across Kentucky; 18% are mobile homes. Half of its homes were built before 1984, close to Kentucky's 1982: 16% date from before 1960 and 27% 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 Adair County, Kentucky, 2019 to 2023
HomesAdair CountyKentucky
Housing units8,6322,010,655
Detached houses74%68%
In buildings of 5 or more4%12%
Mobile homes18%11%
Built before 196016%22%
Built since 200027%24%
Middle year built19841982
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.