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Radon Levels in Trousdale County, Tennessee

EPA puts Trousdale County in Zone 1, its highest radon zone, and only 1 radon test from it is 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

    27.3%

    6.0 pts below TN

    Trousdale
    27.3%
    Tennessee
    33.3%

    33 tests, 2008 to 2017

  • Median result

    1.8pCi/L

    Below action level

    Trousdale
    1.8 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    33

    76th of 80 by tests

    Trousdale
    33
    Davidson
    5,592

    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 Tennessee

    44 of 80

    Middle half

    Trousdale
    27.3%
    Jefferson
    56.8%

    By share, of 80 with 30+ tests

Read a result for Trousdale County

Starts at Trousdale County's median, 1.8 pCi/L

1.8pCi/L

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

EPA’s reading of 1.8 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. Trousdale County's median reported result, 2008 to 2017.

Interpret this reading

The data

Trousdale County, At a glance

Trousdale County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Trousdale 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 Trousdale County, 2023

CDC holds 1 reported test for Trousdale County in 2023, a result of 3.6 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Trousdale County beside the counties around it is how this page reads it.

What these figures count

Only 1 test was reported to CDC for Trousdale 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

Trousdale County, Compared

Trousdale County radon figures, compared

Calculated by Radon411

Trousdale County's 33 reported tests over the 2008 to 2017 laboratory totals had a middle value of 1.8 pCi/L and a maximum of 159.1 pCi/L, and 27.3% reached 4 pCi/L. Tennessee as a whole (95 Tennessee counties, pooled) comes to 33.3%: 6.0 points higher than here.

The newest figure, in 2023, counts only 1 test (0.0% at or above 4 pCi/L), too few to compare, so this reading uses the 33-test figure.

Among its state's counties it ranks 44th of 80 Tennessee counties with 30 or more tests for the same period. Statewide for the same period, Jefferson County reported the highest share (56.8%) and Chester County the lowest (0.0%).

Below the action level, 18 tests (54.5%) came in under 2 pCi/L, against 42.4% statewide, and 6 tests (18.2%) fell between 2 and 4, against 24.3% statewide. CDC's ten-year totals for Trousdale County went from 27 tests (2005 to 2014) to 33 (2008 to 2017), the share going from 37.0% to 27.3%.

EPA's 1993 zone map puts Trousdale County in Zone 1, a predicted county average above 4 pCi/L. USGS geology rates 100% of the county's land high radon potential.

Next door, the shares run from 19.4% in Macon County to 45.5% in Smith County, with Sumner County, Wilson County and Macon County below Trousdale County.

Trousdale County against Tennessee, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Trousdale County
Trousdale County3327.3%1.8 pCi/LThis county
Tennessee, pooled95 counties, pooled31,06633.3%Not pooled+6.0 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+8.4 points
Jefferson Countyhighest in the state14656.8%4.7 pCi/L+29.5 points
Chester Countylowest in the state440.0%1.1 pCi/L−27.3 points
Smith County, TNborders it5545.5%3.1 pCi/L+18.2 points
Sumner County, TNborders it1,31126.0%1.9 pCi/L−1.3 points
Wilson County, TNborders it95920.2%1.7 pCi/L−7.1 points
Macon County, TNborders it6719.4%1.9 pCi/L−7.9 points
Where Trousdale County's reported results fell, 2008 to 2017, laboratory, beside Tennessee and the United States
ResultTrousdale County testsTrousdale County shareTennessee shareU.S. shareAgainst Tennessee
Under 2 pCi/L1854.5%42.4%39.6%+12.1 points
2 to 4 pCi/L618.2%24.3%24.7%−6.1 points
4 pCi/L and above927.3%33.3%35.7%−6.0 points
Trousdale 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
Perry County39 of 804032.5%2.0 pCi/L
DeKalb County40 of 805930.5%3.1 pCi/L
Robertson County41 of 8027328.9%1.9 pCi/L
Marion County42 of 807428.4%1.6 pCi/L
Polk County43 of 804327.9%2.2 pCi/L
Trousdale County44 of 803327.3%1.8 pCi/L
Rhea County45 of 804526.7%2.4 pCi/L
Dickson County46 of 8020926.3%2.1 pCi/L
Stewart County46 of 809526.3%2.1 pCi/L
Sumner County48 of 801,31126.0%1.9 pCi/L
Williamson County49 of 803,41425.8%2.0 pCi/L
Trousdale County ten-year laboratory totals, against Tennessee's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestTennessee, pooledChange from the row before
2008 to 20173327.3%1.8 pCi/L159.1 pCi/L33.3%−0.8 points
2007 to 20163228.1%1.8 pCi/L159.1 pCi/L33.4%−2.9 points
2006 to 20152931.0%1.7 pCi/L159.1 pCi/L33.4%−6.0 points
2005 to 20142737.0%1.8 pCi/L159.1 pCi/L33.2%First on file

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

Trousdale County, Geology

The ground under Trousdale County

Predicted

USGS's geologic map puts all of Trousdale County's mapped land in one class: high radon potential. All of it lies in the area the map calls Nashville Basin, to which USGS gives a radon index of 14, in the high band (12 to 17).

USGS's geologic areas under Trousdale County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Nashville BasinMississippian Limestone.High14100%

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

Trousdale County beside the ground around it

Trousdale County has more high-potential ground than Tennessee as a whole: 100% of its land against 47.2%. Of the 4 counties that border it, none has as large a share of high-potential ground; Macon County comes nearest at 100%.

Share of land by USGS radon potential: Trousdale County, the 4 counties bordering it and Tennessee
AreaEPA zoneLow potentialModerate potentialHigh potential
Trousdale CountyZone 1NoneNone100%
Smith CountyZone 1NoneNone100%
Macon CountyZone 1NoneNone100%
Sumner CountyZone 2None20.4%79.6%
Wilson CountyZone 1NoneNone100%
Tennessee95 counties, pooled by land areaVaries30.5%22.3%47.2%

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

Local help

Trousdale County, Local resources

Radon testing and mitigation in Trousdale County

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

What it means

Trousdale County, Questions

Questions about radon in Trousdale County

Are radon levels high in Trousdale County?

In 2023, 0.0% of the radon tests reported to CDC for Trousdale County, Tennessee were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.6 pCi/L. Of 80 Tennessee counties with 30 or more tests for the same period, 43 reported a higher share; pooled, the state comes to 33.3%.

Which counties border Trousdale County?

Trousdale County borders 4 counties: Smith County, Macon County, Sumner County and Wilson County.

Products

Trousdale County, Products

Testing a home in Trousdale County

In Trousdale County, 27.3% of 33 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 33.3% pooled across Tennessee. In Zone 1 the year-round level in Trousdale 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

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

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Trousdale County, Bordering counties

Counties bordering Trousdale County

Calculated by Radon411

Trousdale County, Cities and towns

Cities and towns in Trousdale County

Trousdale County is growing: the Census Bureau puts it at 12,623 residents on July 1, 2025, up 8.4% from 11,646 in 2020. That works out to 110 people per square mile of land. Hartsville/Trousdale County, its one incorporated place, has 12,623 residents, 100.0% of the total. Reported testing is thin here: 33 tests over 2008 to 2017, or 2.6 for every 1,000 residents (2025 estimate), where Tennessee as a whole comes to 4.2.

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

Hartsville/Trousdale County, Trousdale County: residents on July 1, 2025
PlaceResidentsSince 2020Share of residents
Hartsville/Trousdale County12,623+8.4%100.0%

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).

Trousdale County, Homes

Homes in Trousdale County

Of Trousdale County's 3,866 homes, 70% are detached houses, against 68% across Tennessee; 21% are mobile homes. Half of its homes were built before 1987, close to Tennessee's 1986: 12% date from before 1960 and 32% from 2000 or later. 74% 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 Trousdale County, Tennessee, 2019 to 2023
HomesTrousdale CountyTennessee
Housing units3,8663,095,472
Detached houses70%68%
In buildings of 5 or more4%14%
Mobile homes21%8%
Built before 196012%18%
Built since 200032%29%
Middle year built19871986
Owner-occupied74%67%

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