Skip to content
RADON411

Locations and reports

Radon Levels in Grainger County, Tennessee

EPA puts Grainger County in Zone 1, its highest 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

How to test this homeFind a certified tester

  • Share at 4+ pCi/L

    48.2%

    14.9 pts above TN

    Grainger
    48.2%
    Tennessee
    33.3%

    56 tests, 2008 to 2017

  • Median result

    3.8pCi/L

    Below action level

    Grainger
    3.8 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    56

    58th of 80 by tests

    Grainger
    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

    9 of 80

    Top quarter

    Grainger
    48.2%
    Jefferson
    56.8%

    By share, of 80 with 30+ tests

Read a result for Grainger County

Starts at Grainger County's median, 3.8 pCi/L

3.8pCi/L

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

EPA’s reading of 3.8 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. Grainger County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Grainger County, At a glance

Grainger County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Grainger 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 Grainger County, 2023

Share of reported tests at or above 4 pCi/L, by year, Grainger County
Share of reported tests at or above 4 pCi/L, by year, Grainger County
YearShare of reported tests at or above 4 pCi/L
202216.7%
2023100.0%

2023: 100.0%. Across these years the share ran from 16.7% to 100.0%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

Only 4 tests were reported to CDC for Grainger 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

Grainger County, Compared

Grainger County radon figures, compared

Calculated by Radon411

In Grainger County, about 5 in 10 reported tests over the 2008 to 2017 laboratory totals (27 of 56) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 12.5 points higher. Across 95 Tennessee counties pooled together, 33.3% of tests reached that level, so Grainger County runs 14.9 points above its state.

The newest figure, in 2023, counts only 4 tests (100.0% at or above 4 pCi/L), too few to compare, so this reading uses the 56-test figure.

Of 6 neighbours with a figure, 1 reported a larger share at or above 4 pCi/L and 5 a smaller one; the spread is 33.6% (Knox County) to 56.8% (Jefferson County). By share, Grainger County is 9th of 80 Tennessee counties with 30 or more tests for the same period.

Half the tests came in under 3.8 pCi/L and half over it; the single highest reached 30.1 pCi/L. Below the action level, 18 tests (32.1%) came in under 2 pCi/L, against 42.4% statewide, and 11 tests (19.6%) fell between 2 and 4, against 24.3% statewide.

Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 48.2% share point the same way here. USGS geology rates 100% of the county's land high radon potential.

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

Grainger County against Tennessee, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Grainger County
Grainger County5648.2%3.8 pCi/LThis county
Tennessee, pooled95 counties, pooled31,06633.3%Not pooled−14.9 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−12.5 points
Loudon Countyhighest in the state85954.5%4.4 pCi/L+6.3 points
Chester Countylowest in the state440.0%1.1 pCi/L−48.2 points
Jefferson County, TNborders it14656.8%4.7 pCi/L+8.6 points
Hamblen County, TNborders it18645.2%3.5 pCi/L−3.0 points
Claiborne County, TNborders it12544.0%3.3 pCi/L−4.2 points
Hawkins County, TNborders it28938.4%2.7 pCi/L−9.8 points
Union County, TNborders it5337.7%2.1 pCi/L−10.5 points
Knox County, TNborders it2,45233.6%2.5 pCi/L−14.6 points
Hancock County, TNborders it229.1%1.8 pCi/L−39.1 points
Where Grainger County's reported results fell, 2008 to 2017, laboratory, beside Tennessee and the United States
ResultGrainger County testsGrainger County shareTennessee shareU.S. shareAgainst Tennessee
Under 2 pCi/L1832.1%42.4%39.6%−10.3 points
2 to 4 pCi/L1119.6%24.3%24.7%−4.7 points
4 pCi/L and above2748.2%33.3%35.7%+14.9 points
Grainger 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
Sevier County4 of 8032853.0%4.4 pCi/L
Sullivan County5 of 801,79951.5%4.2 pCi/L
Washington County6 of 801,59049.6%3.9 pCi/L
White County7 of 8014749.0%3.9 pCi/L
Anderson County8 of 8026948.3%3.8 pCi/L
Grainger County9 of 805648.2%3.8 pCi/L
Carter County10 of 8034547.2%3.7 pCi/L
Jackson County11 of 804946.9%3.9 pCi/L
Pickett County12 of 804346.5%3.5 pCi/L
Cocke County13 of 805646.4%3.8 pCi/L
Greene County14 of 8038546.0%3.6 pCi/L
Grainger County radon tests by year, against Tennessee's pooled share
YearTestsAt or above 4 pCi/LMedianHighestTennessee, pooledChange from the row before
20234100.0%12.5 pCi/L17.5 pCi/L24.9%+83.3 points
20221816.7%3.1 pCi/L5.9 pCi/L23.8%First on file

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

Grainger County, Geology

The ground under Grainger County

Predicted

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

USGS's geologic areas under Grainger County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Ridge and ValleyPaleozoic sandstone and cherty dolostone.High14100%

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

Grainger County beside the ground around it

Grainger County has more high-potential ground than Tennessee as a whole: 100% of its land against 47.2%. Of the 7 counties that border it, none has as large a share of high-potential ground; Hamblen County comes nearest at 100%.

Share of land by USGS radon potential: Grainger County, the 7 counties bordering it and Tennessee
AreaEPA zoneLow potentialModerate potentialHigh potential
Grainger CountyZone 1NoneNone100%
Jefferson CountyZone 1NoneNone100%
Hamblen CountyZone 1NoneNone100%
Union CountyZone 1NoneNone100%
Claiborne CountyZone 111.0%None89.0%
Hancock CountyZone 1NoneNone100%
Knox CountyZone 1NoneNone100%
Hawkins 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

Grainger County, Local resources

Radon testing and mitigation in Grainger County

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

What it means

Grainger County, Questions

Questions about radon in Grainger County

Are radon levels high in Grainger County?

In 2023, 100.0% of the radon tests reported to CDC for Grainger County, Tennessee were at or above 4 pCi/L, and the median reported pre-mitigation result was 12.5 pCi/L. Of 80 Tennessee counties with 30 or more tests for the same period, 8 reported a higher share; pooled, the state comes to 33.3%.

Which counties border Grainger County?

Grainger County borders 7 counties: Jefferson County, Hamblen County, Union County, Claiborne County, Hancock County, Knox County and Hawkins County.

Products

Grainger County, Products

Testing a home in Grainger County

In Grainger County, 48.2% 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 Grainger 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

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

Explore

Grainger County, Bordering counties

Counties bordering Grainger County

Calculated by Radon411

Grainger County, Cities and towns

Cities and towns in Grainger County

Grainger County is growing: the Census Bureau puts it at 25,739 residents on July 1, 2025, up 9.2% from 23,572 in 2020. That works out to 92 people per square mile of land. Bean Station, the largest place on its list (3,190 residents in all), extends beyond Grainger County, so no share of the total is worked out for it. Reported testing is thin here: 56 tests over 2008 to 2017, or 2.2 for every 1,000 residents (2025 estimate), where Tennessee as a whole comes to 4.2.

From Bean Station to Rutledge, CDC publishes no figure by town: each reads Grainger County's.

The cities and towns in Grainger County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Bean Stationextends beyond Grainger County3,190+7.7%Counted whole
Blaine2,212+6.4%8.6%
Rutledge1,411+5.1%5.5%

3 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). A place that extends beyond Grainger County is counted whole, so it has no share.

Grainger County, Homes

Homes in Grainger County

Of Grainger County's 11,746 homes, 65% are detached houses, against 68% across Tennessee; 30% are mobile homes. Half of its homes were built before 1992, close to Tennessee's 1986: 14% date from before 1960 and 29% from 2000 or later. Owners live in 79% of the occupied homes (Tennessee: 67%), so for most households a test and a fix are their own to order.

Homes in Grainger County, Tennessee, 2019 to 2023
HomesGrainger CountyTennessee
Housing units11,7463,095,472
Detached houses65%68%
In buildings of 5 or more3%14%
Mobile homes30%8%
Built before 196014%18%
Built since 200029%29%
Middle year built19921986
Owner-occupied79%67%

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