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Radon Levels in Macon County, Tennessee

EPA puts Macon 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

    19.4%

    13.9 pts below TN

    Macon
    19.4%
    Tennessee
    33.3%

    67 tests, 2008 to 2017

  • Median result

    1.9pCi/L

    Below action level

    Macon
    1.9 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    67

    52nd of 80 by tests

    Macon
    67
    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

    59 of 80

    Middle half

    Macon
    19.4%
    Jefferson
    56.8%

    By share, of 80 with 30+ tests

Read a result for Macon County

Starts at Macon County's median, 1.9 pCi/L

1.9pCi/L

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

EPA’s reading of 1.9 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. Macon County's median reported result, 2008 to 2017.

Interpret this reading

The data

Macon County, At a glance

Macon County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Macon 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 Macon County, 2023

Share of reported tests at or above 4 pCi/L, by year, Macon County
Share of reported tests at or above 4 pCi/L, by year, Macon County
YearShare of reported tests at or above 4 pCi/L
20220.0%
2023100.0%

2023: 100.0%. Across these years the share ran from 0.0% to 100.0%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

Only 1 test was reported to CDC for Macon 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

Macon County, Compared

Macon County radon figures, compared

Calculated by Radon411

Macon County's 67 reported tests over the 2008 to 2017 laboratory totals had a middle value of 1.9 pCi/L and a maximum of 33.5 pCi/L, and 19.4% reached 4 pCi/L. Tennessee as a whole (95 Tennessee counties, pooled) comes to 33.3%: 13.9 points higher than here.

The newest figure, in 2023, counts only 1 test (100.0% at or above 4 pCi/L), too few to compare, so this reading uses the 67-test figure.

Among its state's counties it ranks 59th 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, 34 tests (50.7%) came in under 2 pCi/L, against 42.4% statewide, and 20 tests (29.9%) fell between 2 and 4, against 24.3% statewide. The busiest year on file was 2022, with 6 tests reported; the quietest, 2023, had 1.

EPA's 1993 zone map puts Macon 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 26.0% in Sumner County to 52.9% in Monroe County, KY.

Macon County against Tennessee, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Macon County
Macon County6719.4%1.9 pCi/LThis county
Tennessee, pooled95 counties, pooled31,06633.3%Not pooled+13.9 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+16.3 points
Jefferson Countyhighest in the state14656.8%4.7 pCi/L+37.4 points
Chester Countylowest in the state440.0%1.1 pCi/L−19.4 points
Monroe County, KYborders it8752.9%4.6 pCi/L+33.5 points
Jackson County, TNborders it4946.9%3.9 pCi/L+27.5 points
Smith County, TNborders it5545.5%3.1 pCi/L+26.1 points
Clay County, TNborders it4634.8%2.3 pCi/L+15.4 points
Allen County, KYborders it5829.3%1.9 pCi/L+9.9 points
Trousdale County, TNborders it3327.3%1.8 pCi/L+7.9 points
Sumner County, TNborders it1,31126.0%1.9 pCi/L+6.6 points
Where Macon County's reported results fell, 2008 to 2017, laboratory, beside Tennessee and the United States
ResultMacon County testsMacon County shareTennessee shareU.S. shareAgainst Tennessee
Under 2 pCi/L3450.7%42.4%39.6%+8.3 points
2 to 4 pCi/L2029.9%24.3%24.7%+5.6 points
4 pCi/L and above1319.4%33.3%35.7%−13.9 points
Macon 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
Bedford County54 of 8012421.0%1.8 pCi/L
Bradley County55 of 8042520.9%1.9 pCi/L
Lincoln County56 of 8014920.8%1.9 pCi/L
Sequatchie County57 of 805820.7%1.9 pCi/L
Wilson County58 of 8095920.2%1.7 pCi/L
Macon County59 of 806719.4%1.9 pCi/L
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
Macon County radon tests by year, against Tennessee's pooled share
YearTestsAt or above 4 pCi/LMedianHighestTennessee, pooledChange from the row before
20231100.0%4.1 pCi/L4.1 pCi/L24.9%+100.0 points
202260.0%0.5 pCi/L0.7 pCi/L23.8%First on file

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

Macon County, Geology

The ground under Macon County

Predicted

USGS's geologic map puts all of Macon County's mapped land in one class: high radon potential. The map puts 83.2% of Macon County in the area it calls Cherty Highland and 16.8% 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 Macon County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Cherty HighlandCherty dolostone.High1283.2%
Nashville BasinMississippian Limestone.High1416.8%

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

Macon County beside the ground around it

Macon 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; Smith County comes nearest at 100%.

Share of land by USGS radon potential: Macon County, the 7 counties bordering it and Tennessee
AreaEPA zoneLow potentialModerate potentialHigh potential
Macon CountyZone 1NoneNone100%
Trousdale CountyZone 1NoneNone100%
Allen County, KYZone 1None38.5%61.5%
Monroe County, KYZone 1NoneNone100%
Smith CountyZone 1NoneNone100%
Jackson CountyZone 1None18.1%81.9%
Clay CountyZone 2None23.7%76.3%
Sumner CountyZone 2None20.4%79.6%
Tennessee95 counties, pooled by land areaVaries30.5%22.3%47.2%

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

Local help

Macon County, Local resources

Radon testing and mitigation in Macon County

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

What it means

Macon County, Questions

Questions about radon in Macon County

Are radon levels high in Macon County?

In 2023, 100.0% of the radon tests reported to CDC for Macon County, Tennessee were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.1 pCi/L. Of 80 Tennessee counties with 30 or more tests for the same period, 58 reported a higher share; pooled, the state comes to 33.3%.

Which counties border Macon County?

Macon County borders 7 counties: Trousdale County, TN, Allen County, KY, Monroe County, KY, Smith County, TN, Jackson County, TN, Clay County, TN and Sumner County, TN.

Products

Macon County, Products

Testing a home in Macon County

In Macon County, 19.4% of 67 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 Macon 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

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

Explore

Macon County, Bordering counties

Counties bordering Macon County

Calculated by Radon411

Macon County, Cities and towns

Cities and towns in Macon County

Macon County is growing: the Census Bureau puts it at 27,663 residents on July 1, 2025, up 9.5% from 25,260 in 2020. That works out to 90 people per square mile of land. Its largest town, Lafayette, has 6,020 residents, 21.8% of the total. Together its 2 incorporated places hold 26.1% of those residents; the other 73.9% live outside any of them. Reported testing is thin here: 67 tests over 2008 to 2017, or 2.4 for every 1,000 residents (2025 estimate), where Tennessee as a whole comes to 4.2.

From Lafayette to Red Boiling Springs, CDC publishes no figure by town: each reads Macon County's.

The cities and towns in Macon County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Lafayette6,020+7.7%21.8%
Red Boiling Springs1,201−0.1%4.3%

2 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).

Macon County, Homes

Homes in Macon County

Of Macon County's 10,845 homes, 69% are detached houses, against 68% across Tennessee; 22% are mobile homes. Half of its homes were built before 1990, close to Tennessee's 1986: 13% date from before 1960 and 30% from 2000 or later. 72% 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 Macon County, Tennessee, 2019 to 2023
HomesMacon CountyTennessee
Housing units10,8453,095,472
Detached houses69%68%
In buildings of 5 or more3%14%
Mobile homes22%8%
Built before 196013%18%
Built since 200030%29%
Middle year built19901986
Owner-occupied72%67%

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