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Radon Levels in Clay County, Tennessee

EPA puts Clay County in Zone 2, its middle radon zone, and only 2 radon tests from it are on file with CDC (2023). 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

    34.8%

    1.5 pts above TN

    Clay
    34.8%
    Tennessee
    33.3%

    46 tests, 2008 to 2017

  • Median result

    2.3pCi/L

    Below action level

    Clay
    2.3 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    46

    66th of 80 by tests

    Clay
    46
    Davidson
    5,592

    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 Tennessee

    31 of 80

    Middle half

    Clay
    34.8%
    Jefferson
    56.8%

    By share, of 80 with 30+ tests

Read a result for Clay County

Starts at Clay County's median, 2.3 pCi/L

2.3pCi/L

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

EPA’s reading of 2.3 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. Clay County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Clay County, At a glance

Clay County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Clay 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: High across 76% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Clay County, 2023

Share of reported tests at or above 4 pCi/L, by year, Clay County
Share of reported tests at or above 4 pCi/L, by year, Clay County
YearShare of reported tests at or above 4 pCi/L
20220.0%
20230.0%

2023: 0.0%. Across these years the share ran from 0.0% to 0.0%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

Only 2 tests were reported to CDC for Clay County over 2023, and tests are often run on homes being sold or already suspected of a problem: so few describe neither the county nor this house.

Measured: CDC tracking data. Figure above: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).

How to read these figures

Clay County, Compared

Clay County radon figures, compared

Calculated by Radon411

In Clay County, about 3 in 10 reported tests over the 2008 to 2017 laboratory totals (16 of 46) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 0.9 points lower. Across 95 Tennessee counties pooled together, 33.3% of tests reached that level, so Clay County runs 1.5 points above its state.

The newest figure, in 2023, counts only 2 tests (0.0% at or above 4 pCi/L), too few to compare, so this reading uses the 46-test figure.

Of 6 neighbours with a figure, 5 reported a larger share at or above 4 pCi/L and 1 a smaller one; the spread is 19.4% (Macon County) to 52.9% (Monroe County, KY). By share, Clay County is 31st of 80 Tennessee counties with 30 or more tests for the same period.

Half the tests came in under 2.3 pCi/L and half over it; the single highest reached 14.9 pCi/L. Below the action level, 19 tests (41.3%) came in under 2 pCi/L, against 42.4% statewide, and 11 tests (23.9%) fell between 2 and 4, against 24.3% statewide.

Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 34.8% share point the same way here. USGS geology rates 76% of the county's land high radon potential.

The busiest year on file was 2022, with 12 tests reported; the quietest, 2023, had 2.

Clay County against Tennessee, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Clay County
Clay County4634.8%2.3 pCi/LThis county
Tennessee, pooled95 counties, pooled31,06633.3%Not pooled−1.5 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+0.9 points
Jefferson Countyhighest in the state14656.8%4.7 pCi/L+22.0 points
Chester Countylowest in the state440.0%1.1 pCi/L−34.8 points
Cumberland County, KYborders it1855.6%4.6 pCi/L+20.8 points
Monroe County, KYborders it8752.9%4.6 pCi/L+18.1 points
Clinton County, KYborders it4047.5%3.5 pCi/L+12.7 points
Jackson County, TNborders it4946.9%3.9 pCi/L+12.1 points
Pickett County, TNborders it4346.5%3.5 pCi/L+11.7 points
Overton County, TNborders it12840.6%2.8 pCi/L+5.8 points
Macon County, TNborders it6719.4%1.9 pCi/L−15.4 points
Where Clay County's reported results fell, 2008 to 2017, laboratory, beside Tennessee and the United States
ResultClay County testsClay County shareTennessee shareU.S. shareAgainst Tennessee
Under 2 pCi/L1941.3%42.4%39.6%−1.1 points
2 to 4 pCi/L1123.9%24.3%24.7%−0.4 points
4 pCi/L and above1634.8%33.3%35.7%+1.5 points
Clay County ranked among the 80 Tennessee counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Warren County26 of 8014936.9%3.0 pCi/L
Davidson County27 of 805,59236.4%2.6 pCi/L
Putnam County28 of 8033636.0%2.6 pCi/L
Moore County29 of 805135.3%2.9 pCi/L
Hickman County30 of 8012035.0%2.2 pCi/L
Clay County31 of 804634.8%2.3 pCi/L
Johnson County32 of 8015734.4%2.3 pCi/L
Cheatham County33 of 8020534.1%2.3 pCi/L
McMinn County34 of 8010634.0%2.8 pCi/L
Montgomery County35 of 8059733.8%2.3 pCi/L
Roane County36 of 8025833.7%2.5 pCi/L
Clay County radon tests by year, against Tennessee's pooled share
YearTestsAt or above 4 pCi/LMedianHighestTennessee, pooledChange from the row before
202320.0%2.5 pCi/L3.6 pCi/L24.9%Level
2022120.0%1.1 pCi/L2.6 pCi/L23.8%First on file

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

Clay County, Geology

The ground under Clay County

Predicted

Most of the ground under Clay County is one class on USGS's geologic map: 76.3% of its land is high radon potential, with 23.7% moderate. The map puts 38.9% of Clay County in the area it calls Cherty Highland and 23.7% in Highland Rim, with 2 smaller areas beside them. USGS gives the first a radon index of 12, in the high band (12 to 17), and the second 11, in the moderate band (9 to 11).

USGS's geologic areas under Clay County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Cherty HighlandCherty dolostone.High1238.9%
Highland RimPaleozoic sedimentary rocks (limestone, shale, chert, and dolostone).Moderate1123.7%
Nashville BasinMississippian Limestone.High1422.2%
Eastern PennyroyalMarine shale, sandstone and limestone.High1215.3%

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

Clay County beside the ground around it

Clay County has more high-potential ground than Tennessee as a whole: 76.3% of its land against 47.2%. Of the 7 counties that border it, 4 have more high-potential ground, Macon County the most at 100%.

Share of land by USGS radon potential: Clay County, the 7 counties bordering it and Tennessee
AreaEPA zoneLow potentialModerate potentialHigh potential
Clay CountyZone 2None23.7%76.3%
Jackson CountyZone 1None18.1%81.9%
Overton CountyZone 29.5%87.3%3.2%
Monroe County, KYZone 1NoneNone100%
Cumberland County, KYZone 1None13.6%86.4%
Pickett CountyZone 219.1%80.9%None
Macon CountyZone 1NoneNone100%
Clinton County, KYZone 2None83.3%16.7%
Tennessee95 counties, pooled by land areaVaries30.5%22.3%47.2%

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

Local help

Clay County, Local resources

Radon testing and mitigation in Clay County

What Tennessee's program says
Phone
1-800-232-1139
Email
TDEC.Radon@tn.gov

What it means

Clay County, Questions

Questions about radon in Clay County

Are radon levels high in Clay County?

In 2023, 0.0% of the radon tests reported to CDC for Clay County, Tennessee were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.5 pCi/L. Of 80 Tennessee counties with 30 or more tests for the same period, 30 reported a higher share; pooled, the state comes to 33.3%.

Which counties border Clay County?

Clay County borders 7 counties: Jackson County, TN, Overton County, TN, Monroe County, KY, Cumberland County, KY, Pickett County, TN, Macon County, TN and Clinton County, KY.

Products

Clay County, Products

Testing a home in Clay County

In Clay County, 34.8% of 46 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 33.3% pooled across Tennessee. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Clay County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Clay County homes, compared

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Clay County, Bordering counties

Counties bordering Clay County

Calculated by Radon411

Clay County, Cities and towns

Cities and towns in Clay County

The Census Bureau estimates 7,821 residents in Clay County for July 1, 2025, 233 more than in 2020 (+3.1%). That works out to 33 people per square mile of land. Celina, its one incorporated place, has 1,412 residents, 18.1% of the total. CDC's 46 reported tests for 2008 to 2017 work out to 5.9 per 1,000 residents (2025 estimate), close to Tennessee's 4.2.

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

Celina, Clay County: residents on July 1, 2025
PlaceResidentsSince 2020Share of residents
Celina1,412−0.8%18.1%

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).

Clay County, Homes

Homes in Clay County

Of Clay County's 3,987 homes, 63% are detached houses, against 68% across Tennessee; 30% are mobile homes. Half of its homes were built before 1982, close to Tennessee's 1986: 12% date from before 1960 and 20% from 2000 or later. Owners live in 78% of the occupied homes (Tennessee: 67%), so for most households a test and a fix are their own to order.

Homes in Clay County, Tennessee, 2019 to 2023
HomesClay CountyTennessee
Housing units3,9873,095,472
Detached houses63%68%
In buildings of 5 or more4%14%
Mobile homes30%8%
Built before 196012%18%
Built since 200020%29%
Middle year built19821986
Owner-occupied78%67%

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