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Radon Levels in Lewis County, Tennessee

EPA puts Lewis County in Zone 1, its highest radon zone, and 16.1% of its 56 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

    16.1%

    17.2 pts below TN

    Lewis
    16.1%
    Tennessee
    33.3%

    56 tests, 2008 to 2017

  • Median result

    1.4pCi/L

    Below action level

    Lewis
    1.4 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    56

    60th of 80 by tests

    Lewis
    56
    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

    65 of 80

    Lowest quarter

    Lewis
    16.1%
    Jefferson
    56.8%

    By share, of 80 with 30+ tests

Read a result for Lewis County

Starts at Lewis County's median, 1.4 pCi/L

1.4pCi/L

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

EPA’s reading of 1.4 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. Lewis County's median reported result, 2008 to 2017.

Interpret this reading

The data

Lewis County, At a glance

Lewis County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Lewis 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 Lewis County, 2008 to 2017, laboratory

Reported results by concentration band, Lewis County, 2008 to 2017, laboratory
Under 2 pCi/L: 68%2 to 4 pCi/L: 16%4 pCi/L and above: 16%

Of 56 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Lewis County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L3867.9%
2 to 4 pCi/L916.1%
4 pCi/L and above916.1%
What these figures count

These are the 56 tests reported to CDC for Lewis 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

Lewis County, Compared

Lewis County radon figures, compared

Calculated by Radon411

Lewis County's 56 reported tests over the 2008 to 2017 laboratory totals had a middle value of 1.4 pCi/L and a maximum of 30.4 pCi/L, and 16.1% reached 4 pCi/L. Tennessee as a whole (95 Tennessee counties, pooled) comes to 33.3%: 17.2 points higher than here.

Among its state's counties it ranks 65th 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, 38 tests (67.9%) came in under 2 pCi/L, against 42.4% statewide, and 9 tests (16.1%) fell between 2 and 4, against 24.3% statewide. CDC's ten-year totals for Lewis County went from 44 tests (2005 to 2014) to 56 (2008 to 2017), the share going from 18.2% to 16.1%.

EPA's 1993 zone map puts Lewis 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 21.3% in Lawrence County to 39.3% in Maury County.

Lewis County against Tennessee, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Lewis County
Lewis County5616.1%1.4 pCi/LThis county
Tennessee, pooled95 counties, pooled31,06633.3%Not pooled+17.2 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+19.6 points
Jefferson Countyhighest in the state14656.8%4.7 pCi/L+40.7 points
Chester Countylowest in the state440.0%1.1 pCi/L−16.1 points
Maury County, TNborders it50939.3%3.0 pCi/L+23.2 points
Hickman County, TNborders it12035.0%2.2 pCi/L+18.9 points
Perry County, TNborders it4032.5%2.0 pCi/L+16.4 points
Lawrence County, TNborders it13621.3%1.6 pCi/L+5.2 points
Wayne County, TNborders it267.7%1.7 pCi/L−8.4 points
Where Lewis County's reported results fell, 2008 to 2017, laboratory, beside Tennessee and the United States
ResultLewis County testsLewis County shareTennessee shareU.S. shareAgainst Tennessee
Under 2 pCi/L3867.9%42.4%39.6%+25.5 points
2 to 4 pCi/L916.1%24.3%24.7%−8.2 points
4 pCi/L and above916.1%33.3%35.7%−17.2 points
Lewis 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
Hamilton County60 of 801,14819.3%1.7 pCi/L
Marshall County61 of 8013818.1%1.6 pCi/L
Henry County62 of 806016.7%1.6 pCi/L
Henderson County62 of 803016.7%1.6 pCi/L
Coffee County64 of 8020616.5%1.3 pCi/L
Lewis County65 of 805616.1%1.4 pCi/L
Rutherford County66 of 801,20015.3%1.5 pCi/L
Fayette County67 of 809911.1%1.1 pCi/L
Obion County67 of 803611.1%1.8 pCi/L
Cannon County69 of 805610.7%1.3 pCi/L
Fentress County70 of 80339.1%1.3 pCi/L
Lewis County ten-year laboratory totals, against Tennessee's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestTennessee, pooledChange from the row before
2008 to 20175616.1%1.4 pCi/L30.4 pCi/L33.3%−2.1 points
2007 to 20165518.2%1.4 pCi/L30.4 pCi/L33.4%+0.8 points
2006 to 20154617.4%1.3 pCi/L30.4 pCi/L33.4%−0.8 points
2005 to 20144418.2%1.4 pCi/L30.4 pCi/L33.2%First on file

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

Lewis County, Geology

The ground under Lewis County

Predicted

USGS's geologic map puts all of Lewis County's mapped land in one class: high radon potential. The map puts 91.6% of Lewis County in the area it calls Cherty Highland and 8.4% in Nashville Basin. USGS gives the first a radon index of 12 and the second 14, both in the high band (12 to 17).

USGS's geologic areas under Lewis County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Cherty HighlandCherty dolostone.High1291.6%
Nashville BasinMississippian Limestone.High148.4%

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

Lewis County beside the ground around it

Lewis County has more high-potential ground than Tennessee as a whole: 100% of its land against 47.2%. Of the 5 counties that border it, none has as large a share of high-potential ground; Lawrence County comes nearest at 100%.

Share of land by USGS radon potential: Lewis County, the 5 counties bordering it and Tennessee
AreaEPA zoneLow potentialModerate potentialHigh potential
Lewis CountyZone 1NoneNone100%
Lawrence CountyZone 1NoneNone100%
Hickman CountyZone 1None21.2%78.8%
Perry CountyZone 1NoneNone100%
Maury CountyZone 3NoneNone100%
Wayne CountyZone 123.3%None76.7%
Tennessee95 counties, pooled by land areaVaries30.5%22.3%47.2%

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

Local help

Lewis County, Local resources

Radon testing and mitigation in Lewis County

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

What it means

Lewis County, Questions

Questions about radon in Lewis County

Are radon levels high in Lewis County?

Over the 2008 to 2017 laboratory totals, 16.1% of the radon tests reported to CDC for Lewis County, Tennessee were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.4 pCi/L. Of 80 Tennessee counties with 30 or more tests for the same period, 64 reported a higher share; pooled, the state comes to 33.3%.

Which counties border Lewis County?

Lewis County borders 5 counties: Lawrence County, Hickman County, Perry County, Maury County and Wayne County.

Products

Lewis County, Products

Testing a home in Lewis County

In Lewis County, 16.1% of 56 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 Lewis 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

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

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Lewis County, Bordering counties

Counties bordering Lewis County

Calculated by Radon411

Lewis County, Cities and towns

Cities and towns in Lewis County

Lewis County is growing: the Census Bureau puts it at 13,487 residents on July 1, 2025, up 7.0% from 12,609 in 2020. That works out to 48 people per square mile of land. Hohenwald, its one incorporated place, has 4,151 residents, 30.8% of the total. CDC's 56 reported tests for 2008 to 2017 work out to 4.2 per 1,000 residents (2025 estimate), close to Tennessee's 4.2.

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

Hohenwald, Lewis County: residents on July 1, 2025
PlaceResidentsSince 2020Share of residents
Hohenwald4,151+12.2%30.8%

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).

Lewis County, Homes

Homes in Lewis County

Of Lewis County's 5,746 homes, 71% are detached houses, against 68% across Tennessee; 27% are mobile homes. Half of its homes were built before 1990, close to Tennessee's 1986: 12% date from before 1960 and 27% from 2000 or later. Owners live in 80% of the occupied homes (Tennessee: 67%), so for most households a test and a fix are their own to order.

Homes in Lewis County, Tennessee, 2019 to 2023
HomesLewis CountyTennessee
Housing units5,7463,095,472
Detached houses71%68%
In buildings of 5 or more2%14%
Mobile homes27%8%
Built before 196012%18%
Built since 200027%29%
Middle year built19901986
Owner-occupied80%67%

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