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Radon Levels in Marshall County, Tennessee

Zone 1Highest predicted potential379 square miles · 6 bordering counties

What this means for you

  • Your area: EPA rates Marshall County Zone 1, the highest of its three radon zones. That is a prediction for the whole county, and homes with elevated levels occur in all three zones.
  • Local tests: 1 buildings with radon tests reported to CDC for Marshall County (2023). CDC publishes no share above the action level here.
  • Your home: The only way to know your home’s level is to test it.

pCi/L (picocuries per liter) is the unit radon is measured in. EPA recommends fixing a home at 4 pCi/L or above, its action level.

In 2023, the median radon test reported to CDC for Marshall County, Tennessee was 1.8 pCi/L. EPA's Map of Radon Zones places the county in Zone 1, highest predicted potential. Radon levels vary from home to home, so only a test measures the level in yours.

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA predicts an average indoor of greater than 4 pCi/L (greater than 150 Bq/m³) across the county as a whole.

This is a county-level geologic prediction. It is not a measurement of any address, and houses with elevated radon are found in all three zones.

USGS geologic potential: Low across 100% of the county's land area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Marshall County, 2023

Buildings tested
1
At or above 4 pCi/L
Not available
Median result
1.8 pCi/L

Distribution of tested buildings, not this house. People testing before a sale, or because they suspect a problem, are over-represented in any reported testing data.

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

Marshall County, In figures

Marshall County in figures

What the published data says about Marshall County, in words. A zone and a share of tests describe an area, never the level in any one home.

    • Predicted

      Predicted

      EPA places Marshall County in Zone 1, highest predicted potential, as it does 38 other counties of Tennessee's 95.

      Of the 6 bordering counties, EPA places Bedford County, Giles County, Lincoln County, Rutherford County and Williamson County in Zone 1 and Maury County in Zone 3.

  • Reported tests

    Measured

    CDC has one annual figure for Marshall County on file here, for 2022: 0.0% of 3 reported tests were at or above 4 pCi/L.

  • Local record

    Tennessee's radon program is the Tennessee Radon Program, run by Department of Environment & Conservation; its contacts are under Local resources.

    The county's largest incorporated places are Lewisburg, Chapel Hill and Cornersville; the figures here cover them as part of the county.

Marshall County, Reported testing

Reported testing over time

Measured
Reported radon test results by year, Marshall County, pCi/LLogarithmic scale: each step up the axis multiplies the level, so the median and the single highest result can share one chart. The darker gridline is EPA's action level, 4 pCi/L.
Median reported resultHighest reported result
Reported radon test results by year, Marshall County, pCi/L: data table
YearMedian reported resultHighest reported resultShare of tests at or above 4 pCi/L
20220.9 pCi/L0.9 pCi/L0.0%
20231.8 pCi/L1.8 pCi/LNo data

What these figures count

Every percentage here is a share of radon tests reported to CDC for Marshall County in 2023. It is not a share of homes in Marshall County, and it is not a random sample: it counts only the tests people chose to run and that were reported.

The shares and the median are calculated from pre-mitigation tests. CDC also reports the number of buildings tested (1), a different count, so the two totals are not interchangeable.

Marshall County, Comparison

How Marshall County compares

Measured

Marshall County's own published CDC figures beside those of the counties that border it, for the same period.

Share of reported tests at or above 4 pCi/L

Measured

2023, highest first. Each county’s own published CDC figure.

Marshall County has no published figure for this measure in 2023, so it is not ranked here.

Median reported result

Measured

2023, highest first. Each county’s own published CDC figure.

  1. Giles CountyTNTest count not published4.3 pCi/L
  2. Lincoln CountyTNTest count not published3.0 pCi/L
  3. Maury CountyTN8 tests3.0 pCi/L
  4. Marshall CountyThis pageTest count not published1.8 pCi/L
  5. Rutherford CountyTN50 tests1.6 pCi/L
  6. Bedford CountyTNTest count not published1.4 pCi/L
  7. Williamson CountyTN115 tests1.3 pCi/L

Each figure is that county’s own published CDC figure for 2023, counting radon tests reported to CDC, not homes. Marshall County is this page. Nothing is averaged or combined across counties. The test count beside each county is CDC’s published number of pre-mitigation tests behind its figures. Figures from few tests can swing widely from year to year. Every Tennessee county’s own figure is in the Tennessee county table.

CDC publishes this figure only for counties here, so there is no state or national number to compare Marshall County, Tennessee with.

Marshall County, Bordering counties

Counties bordering Marshall County

Calculated by Radon411

6 counties share a boundary with Marshall County, computed from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county’s report can be worth reading alongside this one.

Marshall County, Local resources

Local resources in Tennessee

Who to ask in Tennessee: the state's radon program, test kits and professionals.

Tennessee Radon Program

Department of Environment & Conservation

Tennessee’s radon program answers questions about testing, mitigation and the rules where you live.

Phone
1-800-232-1139
Email
TDEC.Radon@tn.gov
Visit the program's page(opens in a new tab)

Test kits

The program says: The Tennessee Radon Program provides free radon test kits and information assistance to residents, while also providing training opportunities to radon professionals across the state.

Radon professionals

1 professional is listed in Tennessee.

Professionals in Tennessee

Marshall County, Cities and towns

Cities and towns in Marshall County

The radon figures on this page are for Marshall County as a whole. They do not differ by city or town.

  • Lewisburg
  • Chapel Hill
  • Cornersville
  • Petersburg (part)

4 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. “(part)” marks a place that extends into another county.

Marshall County, Questions

Questions about radon in Marshall County

Common questions8 questions, answered from the figures above

Are radon levels high in Marshall County?

No CDC testing statistics are published here for Marshall County, Tennessee yet. EPA places Marshall County in Zone 1, highest predicted potential, a predicted average indoor screening level greater than 4 pCi/L. Homes with elevated levels occur in all three zones, so the figures describe the area, not your house. Testing is the only way to know the radon level in a specific building.

What a radon level meansRadon in Tennessee

How do I get a radon test in Marshall County?

EPA says you can test your home yourself or hire a qualified radon test company, and that either approach takes only a small amount of time and effort. No certified tester listed on Radon411 names Marshall County as a service area yet. The Tennessee radon program is the place to ask about certified testers and any test kit offer it runs.

How to test a homeTest kits comparedFree and low-cost kits by stateTennessee radon program

Who does radon mitigation in Marshall County?

No listed mitigator names Marshall County as a service area yet; the Tennessee directory lists 1 company. EPA recommends having a qualified contractor fix a home with a radon problem, because lowering high radon levels takes technical knowledge and special skills, and some states require the work to be done by a licensed or certified professional. Your state radon program is the place to check whether Tennessee requires one.

How radon mitigation worksWhat mitigation costsMitigators in Tennessee

What EPA radon zone is Marshall County in?

EPA places Marshall County, Tennessee in Zone 1, which EPA describes as highest predicted potential for the area. A zone is a prediction for the whole county and never determines whether a particular home should be tested. EPA recommends testing every home regardless of zone.

Should I test my home in Marshall County?

Yes. Testing is the only way to know the radon level in a specific building. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. How to test a home.

When is the best time of year to test?

EPA says short-term tests stay in the home from 2 to 90 days and that all radon tests should run a minimum of 48 hours; long-term tests stay more than 90 days. EPA's guides do not name a best season: they say radon levels tend to vary from day to day and season to season, so a long-term test is more likely than a short-term test to tell you the year-round average.

What does it cost to test?

EPA's Citizen's Guide calls testing easy and inexpensive, and EPA's Home Buyer's and Seller's Guide says passive short-term and long-term devices are generally inexpensive, while active devices may cost more. No national average price is published for this, so Radon411 does not give one. What testing costs.

Which counties border Marshall County?

Marshall County borders 6 counties, derived from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county's report can be relevant.

What these figures mean if you own, buy, sell or rent

The EPA zone on this page describes Marshall County as a whole. It is a prediction for an area, and it does not measure your building.

  • If you own your home

    Test the lowest lived-in level; a short-term kit screens in days, a long-term kit reflects the year.

    How to test a home
  • If you are buying

    Ask for past results and any system's post-mitigation test, and test during the sale.

    Buying a house: radon guide
  • If you are selling

    Testing before you list puts the timing in your hands; disclosure rules differ by state.

    Selling a house: radon guide
  • If you rent, or rent out a home

    A tenant can test; a fix is the owner's to make, and duties differ by state.

    Radon in rental homes

How long a test has to run, under what conditions, and what EPA says a result means: the testing standard, in full.

Marshall County, Products

Testing and mitigation products

Whatever the figures for Marshall County show, only a test tells you about one home.

Marshall County / Next steps

What to do next

Informational. Follow EPA guidance. EPA says all radon tests should be taken for a minimum of 48 hours, with windows and doors closed from 12 hours before a short-term test.