Short-term kit
RA100 short-term liquid scintillation radon test kit
- Lab fee extra
Method: Liquid scintillation
In home: 48 to 96 hours
Locations and reports
Radon Levels in Carroll County, Missouri
EPA puts Carroll County in Zone 2, its middle 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
Highest bordering
49.1%
Saline County
- Saline
- 49.1%
- Livingston
- 22.4%
4 of 6 neighbours have 30+ tests, 2008 to 2017
Nearest county
22.4%
Livingston County, 25 miles
- Livingston
- 22.4%
- Missouri
- 30.6%
Share at 4+ pCi/L, 49 tests, 2008 to 2017
Ground above low
100.0%
5.8 pts above Missouri
- Carroll
- 100.0%
- Missouri
- 94.2%
Share of land USGS rates moderate or high potential
Tests reported
18
Too few for a share
- Carroll
- 18
- Needed
- 30
2008 to 2017, laboratory
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
EPA predicts 2 to 4 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 2: moderate predicted potential
Carroll County is a
USGS geologic potential: Moderate across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Carroll County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 0.0% |
| 2017 | 75.0% |
| 2018 | 0.0% |
| 2022 | 0.0% |
| 2023 | 100.0% |
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 Carroll 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).
Carroll County, Compared
Carroll County radon figures, compared
Calculated by Radon411CDC's largest figure for Carroll County rests on 18 tests over the 2008 to 2017 laboratory totals, 6 of them at or above 4 pCi/L, so each test moves its share by 5.6 points and no rank or comparison is drawn from it. Results reached as high as 28.2 pCi/L, with a middle value of 2.7 pCi/L.
Of the counties bordering it, 4 have a figure over the 2008 to 2017 laboratory totals: Saline County reported the largest share at or above 4 pCi/L, 49.1%, and Livingston County the smallest, 22.4%, with Lafayette County at 46.7% and Ray County at 38.9% between. Farther out, Linn County (37 miles away) at 18.9%, Daviess County (45 miles away) at 26.7% and Howard County (48 miles away) at 43.5% have figures too. Pooled across 115 Missouri counties, 30.6% of reported tests reached that level; across every county in the country with a figure, 35.7%.
Statewide for the same period, Atchison County reported the highest share (69.9%) and Vernon County the lowest (8.8%). EPA's 1993 map puts Carroll County in Zone 2, its middle label: a predicted county average between 2 and 4 pCi/L. USGS geology rates 100% of the county's land moderate 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 puts all of Carroll County's mapped land in one class: moderate radon potential. 99.3% of it lies in the area the map calls Dissected Till Plains, to which USGS gives a radon index of 11, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Dissected Till Plains | Till-covered Pennsylvanian sandstone, shale, and limestone. | Moderate | 11 | 99.3% |
| Osage Plains | Ordovician dolomite, sandstone, limestone, and shale. | Moderate | 11 | 0.7% |
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 Missouri 8.2% of the land is rated high; none of Carroll County's is. Of the 6 counties that border it, none has as large a share of moderate-potential ground; Caldwell County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Carroll County, Local resources
Radon testing and mitigation in Carroll County
- Missouri Radon ProgramMissouri Radon Program, run by Missouri Department of Health and Senior Services, offers free or discounted test kits, and answers questions about testing and mitigation in Missouri.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Free radon test kits are available for Missouri residents (limit one per household).
- Compare kits
- Professionals in Missouri27 professionals are listed in Missouri.
What Missouri's program says
- Phone
- 573-751-6102
- radon@health.mo.gov
What it means
Carroll County, Questions
Questions about radon in Carroll County
Are radon levels high in Carroll County?
In 2023, 100.0% of the radon tests reported to CDC for Carroll County, Missouri were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.9 pCi/L. Of the counties bordering it, 4 have a figure over the 2008 to 2017 laboratory totals: Saline County reported the largest share at or above 4 pCi/L, 49.1%, and Livingston County the smallest, 22.4%, with Lafayette County at 46.7% and Ray County at 38.9% between.
Which counties border Carroll County?
Carroll County borders 6 counties: Saline County, Chariton County, Ray County, Lafayette County, Livingston County and Caldwell County.
Products
Carroll County, Products
Testing a home in Carroll County
No CDC figure names Carroll County; the nearest county with one, Livingston County (25 miles away), reported 22.4% 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. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Carroll County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
MonitorForensics Detectors
FD-65-RADON rechargeable radon detector with a color screen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
First reading: Within 6 hours
- 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 Saline CountyEPA zone 2
49.1%at or above 4 pCi/L
Median 3.7 pCi/L · 55 tests
- Radon levels in Lafayette CountyEPA zone 2
46.7%at or above 4 pCi/L
Median 3.5 pCi/L · 184 tests
- Radon levels in Ray CountyEPA zone 2
38.9%at or above 4 pCi/L
Median 2.5 pCi/L · 108 tests
- Radon levels in Livingston CountyEPA zone 2
22.4%at or above 4 pCi/L
Median 2.1 pCi/L · 49 tests
- Radon levels in Chariton CountyEPA zone 2
13.3%at or above 4 pCi/L
Median 1.7 pCi/L · 15 tests
- Radon levels in Caldwell CountyEPA zone 2
6.3%at or above 4 pCi/L
Median 1.5 pCi/L · 16 tests
Carroll County, Cities and towns
Cities and towns in Carroll County
About 8,417 people live in Carroll County by the Census Bureau's estimate for July 1, 2025, 49 fewer than in 2020 (−0.6%). That works out to 12 people per square mile of land. Its largest town, Carrollton, has 3,499 residents, 41.6% of the total. Together its 7 incorporated places hold 60.6% of those residents; the other 39.4% live outside any of them. Reported testing is thin here: 18 tests over 2008 to 2017, or 2.1 for every 1,000 residents (2025 estimate), where Missouri as a whole comes to 9.3.
From Carrollton to De Witt, CDC publishes no figure by town: each reads Carroll County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Carrollton | 3,499 | −0.1% | 41.6% |
| Norborne | 632 | −0.5% | 7.5% |
| Hale | 375 | −0.5% | 4.5% |
| Bosworth | 208 | −1.4% | 2.5% |
| Bogard | 162 | −1.2% | 1.9% |
| Tina | 138 | Level | 1.6% |
| De Witt | 83 | −1.2% | 1.0% |
7 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).
Carroll County, Homes
Homes in Carroll County
Carroll County is a place of houses on their own lots: 84% of its 4,380 homes are detached single-family houses, against 70% across Missouri. The homes are older than Missouri's as a whole: half were built before 1964 (1978 for Missouri), and 44% date from before 1960. 73% of occupied homes are lived in by their owner (Missouri: 68%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Carroll County | Missouri |
|---|---|---|
| Housing units | 4,380 | 2,809,501 |
| Detached houses | 84% | 70% |
| In buildings of 5 or more | 2% | 13% |
| Mobile homes | 9% | 5% |
| Built before 1960 | 44% | 28% |
| Built since 2000 | 11% | 21% |
| Middle year built | 1964 | 1978 |
| Owner-occupied | 73% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.