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Radon Levels in Warren County, Tennessee

EPA puts Warren County in Zone 2, its middle radon zone, and only 4 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

    36.9%

    3.6 pts above TN

    Warren
    36.9%
    Tennessee
    33.3%

    149 tests, 2008 to 2017

  • Median result

    3.0pCi/L

    Below action level

    Warren
    3.0 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    149

    32nd of 80 by tests

    Warren
    149
    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

    26 of 80

    Middle half

    Warren
    36.9%
    Jefferson
    56.8%

    By share, of 80 with 30+ tests

Read a result for Warren County

Starts at Warren County's median, 3.0 pCi/L

3.0pCi/L

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

EPA’s reading of 3.0 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. Warren County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Warren County, At a glance

Warren County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Warren 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 95% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Warren County, 2023

Share of reported tests at or above 4 pCi/L, by year, Warren County
Share of reported tests at or above 4 pCi/L, by year, Warren County
YearShare of reported tests at or above 4 pCi/L
202216.7%
202350.0%

2023: 50.0%. Across these years the share ran from 16.7% to 50.0%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

Only 4 tests were reported to CDC for Warren 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

Warren County, Compared

Warren County radon figures, compared

Calculated by Radon411

In Warren County, about 4 in 10 reported tests over the 2008 to 2017 laboratory totals (55 of 149) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 1.2 points higher. Across 95 Tennessee counties pooled together, 33.3% of tests reached that level, so Warren County runs 3.6 points above its state.

The newest figure, in 2023, counts only 4 tests (50.0% at or above 4 pCi/L), too few to compare, so this reading uses the 149-test figure.

Of 5 neighbours with a figure, 1 reported a larger share at or above 4 pCi/L and 4 a smaller one; the spread is 10.7% (Cannon County) to 49.0% (White County). By share, Warren County is 26th of 80 Tennessee counties with 30 or more tests for the same period.

Half the tests came in under 3.0 pCi/L and half over it; the single highest reached 39.5 pCi/L. Below the action level, 58 tests (38.9%) came in under 2 pCi/L, against 42.4% statewide, and 36 tests (24.2%) 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 36.9% share point the same way here. USGS geology rates 95% of the county's land moderate radon potential.

The busiest year on file was 2022, with 18 tests reported; the quietest, 2023, had 4.

Warren County against Tennessee, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Warren County
Warren County14936.9%3.0 pCi/LThis county
Tennessee, pooled95 counties, pooled31,06633.3%Not pooled−3.6 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−1.2 points
Jefferson Countyhighest in the state14656.8%4.7 pCi/L+19.9 points
Chester Countylowest in the state440.0%1.1 pCi/L−36.9 points
White County, TNborders it14749.0%3.9 pCi/L+12.1 points
Van Buren County, TNborders it2240.9%2.1 pCi/L+4.0 points
DeKalb County, TNborders it5930.5%3.1 pCi/L−6.4 points
Sequatchie County, TNborders it5820.7%1.9 pCi/L−16.2 points
Coffee County, TNborders it20616.5%1.3 pCi/L−20.4 points
Cannon County, TNborders it5610.7%1.3 pCi/L−26.2 points
Grundy County, TNborders it290.0%1.0 pCi/L−36.9 points
Where Warren County's reported results fell, 2008 to 2017, laboratory, beside Tennessee and the United States
ResultWarren County testsWarren County shareTennessee shareU.S. shareAgainst Tennessee
Under 2 pCi/L5838.9%42.4%39.6%−3.5 points
2 to 4 pCi/L3624.2%24.3%24.7%−0.1 points
4 pCi/L and above5536.9%33.3%35.7%+3.6 points
Warren 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
Overton County21 of 8012840.6%2.8 pCi/L
Maury County22 of 8050939.3%3.0 pCi/L
Hawkins County23 of 8028938.4%2.7 pCi/L
Union County24 of 805337.7%2.1 pCi/L
Unicoi County25 of 8013237.1%2.8 pCi/L
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
Warren County radon tests by year, against Tennessee's pooled share
YearTestsAt or above 4 pCi/LMedianHighestTennessee, pooledChange from the row before
2023450.0%4.0 pCi/L5.1 pCi/L24.9%+33.3 points
20221816.7%1.5 pCi/L47.0 pCi/L23.8%First on file

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

Warren County, Geology

The ground under Warren County

Predicted

Most of the ground under Warren County is one class on USGS's geologic map: 95.3% of its land is moderate radon potential, with 4.7% low. 95.3% of it lies in the area the map calls Highland Rim, to which USGS gives a radon index of 11, in the moderate band (9 to 11).

USGS's geologic areas under Warren County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Highland RimPaleozoic sedimentary rocks (limestone, shale, chert, and dolostone).Moderate1195.3%
Appalachian PlateauSandstone and shale.Low84.7%

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

Warren County beside the ground around it

Across Tennessee 47.2% of the land is rated high; none of Warren County's is. Of the 7 counties that border it, 4 have more high-potential ground, DeKalb County the most at 62.9%.

Share of land by USGS radon potential: Warren County, the 7 counties bordering it and Tennessee
AreaEPA zoneLow potentialModerate potentialHigh potential
Warren CountyZone 24.7%95.3%None
Cannon CountyZone 2None42.6%57.4%
Van Buren CountyZone 262.4%37.6%None
Coffee CountyZone 2None87.8%12.2%
DeKalb CountyZone 2None37.1%62.9%
Grundy CountyZone 369.0%30.2%0.8%
White CountyZone 214.1%85.9%None
Sequatchie CountyZone 3100%NoneNone
Tennessee95 counties, pooled by land areaVaries30.5%22.3%47.2%

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

Local help

Warren County, Local resources

Radon testing and mitigation in Warren County

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

What it means

Warren County, Questions

Questions about radon in Warren County

Are radon levels high in Warren County?

In 2023, 50.0% of the radon tests reported to CDC for Warren County, Tennessee were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.0 pCi/L. Of 80 Tennessee counties with 30 or more tests for the same period, 25 reported a higher share; pooled, the state comes to 33.3%.

Which counties border Warren County?

Warren County borders 7 counties: Cannon County, Van Buren County, Coffee County, DeKalb County, Grundy County, White County and Sequatchie County.

Products

Warren County, Products

Testing a home in Warren County

In Warren County, 36.9% of 149 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 Warren County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Warren County homes, compared

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Warren County, Bordering counties

Counties bordering Warren County

Calculated by Radon411

Warren County, Cities and towns

Cities and towns in Warren County

Warren County is growing: the Census Bureau puts it at 43,717 residents on July 1, 2025, up 6.5% from 41,057 in 2020. That works out to 101 people per square mile of land. Its largest town, McMinnville, has 13,943 residents, 31.9% of the total. Together its 4 incorporated places hold 34.7% of those residents; the other 65.3% live outside any of them. CDC's 149 reported tests for 2008 to 2017 work out to 3.4 per 1,000 residents (2025 estimate), close to Tennessee's 4.2.

From McMinnville to Viola, CDC publishes no figure by town: each reads Warren County's.

The cities and towns in Warren County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
McMinnville13,943+1.0%31.9%
Morrison785+6.9%1.8%
Centertown326+9.4%0.7%
Viola111+8.8%0.3%

4 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).

Warren County, Homes

Homes in Warren County

Of Warren County's 18,343 homes, 72% are detached houses, against 68% across Tennessee; 14% are mobile homes. The homes are older than Tennessee's as a whole: half were built before 1978 (1986 for Tennessee), and 18% date from before 1960. 71% of occupied homes are lived in by their owner (Tennessee: 67%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Warren County, Tennessee, 2019 to 2023
HomesWarren CountyTennessee
Housing units18,3433,095,472
Detached houses72%68%
In buildings of 5 or more5%14%
Mobile homes14%8%
Built before 196018%18%
Built since 200017%29%
Middle year built19781986
Owner-occupied71%67%

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