Short-term kit
RA400 short-term liquid scintillation radon test kit, lab fee included
- Lab fee included
Method: Liquid scintillation
In home: 48 to 96 hours
Locations and reports
Radon Levels in Carroll County, Tennessee
EPA puts Carroll County in Zone 3, its lowest radon zone, and only 3 radon tests from it are on file with CDC (2022). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Highest bordering
33.3%
Benton County
- Benton
- 33.3%
- Gibson
- 5.3%
5 of 7 neighbours have 30+ tests, 2008 to 2017
Nearest county
16.7%
Henderson County, 22 miles
- Henderson
- 16.7%
- Tennessee
- 33.3%
Share at 4+ pCi/L, 30 tests, 2008 to 2017
Ground above low
25.1%
44.4 pts below Tennessee
- Carroll
- 25.1%
- Tennessee
- 69.5%
Share of land USGS rates moderate or high potential
Tests reported
25
Too few for a share
- Carroll
- 25
- Needed
- 30
2008 to 2017, laboratory
EPA radon zone
Zone 3
Lower potential
- 1
- 2
- Zone 3
1 highest, 3 lowest
EPA predicts under 2 pCi/L indoors
Read a result for Carroll County
Starts at EPA's action level
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 4.0 pCi/L
At or above 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher.
The data
Carroll County, At a glance
Carroll County at a glance
Predicted: EPA radon zone
EPA Zone 3: lower predicted potential
USGS geologic potential: Low across 75% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Carroll County, 2022
CDC holds 3 reported tests for Carroll County in 2022, with a median of 1.3 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Carroll County beside the counties around it is how this page reads it.
What these figures count
Only 3 tests were reported to CDC for Carroll County over 2022, 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: 2022. Measured data period: 2005 to 2022 (every CDC figure on file).
Carroll County, Compared
Carroll County radon figures, compared
Calculated by Radon411CDC's largest figure for Carroll County rests on 25 tests over the 2008 to 2017 laboratory totals, 5 of them at or above 4 pCi/L, so each test moves its share by 4.0 points and no rank or comparison is drawn from it. Results reached as high as 7.0 pCi/L, with a middle value of 1.0 pCi/L.
Of the counties bordering it, 5 have a figure over the 2008 to 2017 laboratory totals: Benton County reported the largest share at or above 4 pCi/L, 33.3%, and Gibson County the smallest, 5.3%, with Henderson County at 16.7%, Henry County at 16.7% and Madison County at 8.7% between. Farther out, Humphreys County (38 miles away) at 23.8%, Chester County (39 miles away) at 0.0% and Perry County (40 miles away) at 32.5% have figures too. Pooled across 95 Tennessee counties, 33.3% of reported tests reached that level; across every county in the country with a figure, 35.7%.
Statewide for the same period, Jefferson County reported the highest share (56.8%) and Chester County the lowest (0.0%). EPA's 1993 map puts Carroll County in Zone 3, its lowest label: a predicted county average under 2 pCi/L. USGS geology rates 75% of the county's land low radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Carroll County, Geology
The ground under Carroll County
PredictedUSGS's geologic map splits Carroll County: 74.9% of its land is low radon potential and 25.1% moderate. The map puts 74.9% of Carroll County in the area it calls Loess-Covered Coastal Plain and 25.1% in East Coastal Plain. USGS gives the first a radon index of 8, in the low band (5 to 8), and the second 9, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Loess-Covered Coastal Plain | Cretaceous and younger marine and fluvial sand, clay, and marl covered with loess. | Low | 8 | 74.9% |
| East Coastal Plain | Cretaceous and younger marine and fluvial sand, clay, and marl. | Moderate | 9 | 25.1% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Carroll County beside the ground around it
Across Tennessee 47.2% of the land is rated high; none of Carroll County's is. Of the 7 counties that border it, 3 have more high-potential ground, Decatur County the most at 67.3%.
The map rates the ground, not the air in any home.
Local help
Carroll County, Local resources
Radon testing and mitigation in Carroll County
- Tennessee Radon ProgramTennessee Radon Program, run by Department of Environment & Conservation, offers free or discounted test kits, and answers questions about testing and mitigation in Tennessee.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe 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.
- Compare kits
- Professionals in Tennessee1 professional is listed in Tennessee.
What Tennessee's program says
- Phone
- 1-800-232-1139
- TDEC.Radon@tn.gov
What it means
Carroll County, Questions
Questions about radon in Carroll County
Are radon levels high in Carroll County?
In 2022, 0.0% of the radon tests reported to CDC for Carroll County, Tennessee were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.3 pCi/L. Of the counties bordering it, 5 have a figure over the 2008 to 2017 laboratory totals: Benton County reported the largest share at or above 4 pCi/L, 33.3%, and Gibson County the smallest, 5.3%, with Henderson County at 16.7%, Henry County at 16.7% and Madison County at 8.7% between.
Which counties border Carroll County?
Carroll County borders 7 counties: Henderson County, Benton County, Gibson County, Henry County, Weakley County, Decatur County and Madison County.
Products
Carroll County, Products
Testing a home in Carroll County
No CDC figure names Carroll County; the nearest county with one, Henderson County (22 miles away), reported 16.7% of its tests at or above 4 pCi/L over the 2008 to 2017 laboratory totals, the only reading nearby until a test of this home. Zone 3 is the lowest label, yet homes at or above 4 pCi/L occur in every zone: a short-term kit (2 to 90 days) is the quick first check in Carroll County.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL416 long-term radon test kit, lab fee included
- Lab fee included
Method: Alpha track
In home: 90 days to 12 months
MonitorAEGTEST
HOUND-3786 rechargeable radon monitor with a 3.5-inch color screen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Ion chamber
First reading: Within 10 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Carroll County, Bordering counties
Counties bordering Carroll County
Calculated by Radon411- Radon levels in Benton CountyEPA zone 2
33.3%at or above 4 pCi/L
Median 2.0 pCi/L · 30 tests
- Radon levels in Decatur CountyEPA zone 2
29.4%at or above 4 pCi/L
Median 1.7 pCi/L · 17 tests
- Radon levels in Henderson CountyEPA zone 2
16.7%at or above 4 pCi/L
Median 1.6 pCi/L · 30 tests
- Radon levels in Henry CountyEPA zone 3
16.7%at or above 4 pCi/L
Median 1.6 pCi/L · 60 tests
- Radon levels in Weakley CountyEPA zone 3
12.5%at or above 4 pCi/L
Median 1.1 pCi/L · 16 tests
- Radon levels in Madison CountyEPA zone 1
8.7%at or above 4 pCi/L
Median 1.2 pCi/L · 92 tests
- Radon levels in Gibson CountyEPA zone 3
5.3%at or above 4 pCi/L
Median 1.0 pCi/L · 57 tests
Carroll County, Cities and towns
Cities and towns in Carroll County
The Census Bureau estimates 29,200 residents in Carroll County for July 1, 2025, 773 more than in 2020 (+2.7%). That works out to 49 people per square mile of land. McKenzie, the largest place on its list (5,632 residents in all), extends beyond Carroll County, so no share of the total is worked out for it. Reported testing is thin here: 25 tests over 2008 to 2017, or 0.9 for every 1,000 residents (2025 estimate), where Tennessee as a whole comes to 4.2.
From McKenzie to McLemoresville, CDC publishes no figure by town: each reads Carroll County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| McKenzieextends beyond Carroll County | 5,632 | +1.9% | Counted whole |
| Huntingdon | 4,462 | +0.6% | 15.3% |
| Bruceton | 1,522 | +1.1% | 5.2% |
| Atwood | 966 | +3.1% | 3.3% |
| Trezevant | 815 | +3.0% | 2.8% |
| Hollow Rock | 703 | +3.5% | 2.4% |
| Clarksburg | 389 | +3.2% | 1.3% |
| McLemoresville | 301 | +1.3% | 1.0% |
8 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 Carroll County is counted whole, so it has no share.
Carroll County, Homes
Homes in Carroll County
Of Carroll County's 13,107 homes, 73% are detached houses, against 68% across Tennessee; 17% are mobile homes. The homes are older than Tennessee's as a whole: half were built before 1977 (1986 for Tennessee), and 23% date from before 1960. 75% 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 | Carroll County | Tennessee |
|---|---|---|
| Housing units | 13,107 | 3,095,472 |
| Detached houses | 73% | 68% |
| In buildings of 5 or more | 4% | 14% |
| Mobile homes | 17% | 8% |
| Built before 1960 | 23% | 18% |
| Built since 2000 | 18% | 29% |
| Middle year built | 1977 | 1986 |
| Owner-occupied | 75% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.