Short-term kit
Air Chek Short-Term radon test kit you hang, lab fee included
- Lab fee included
In home: 72 to 168 hours
Locations and reports
Radon Levels in DeKalb County, Missouri
EPA puts DeKalb County in Zone 2, its middle radon zone, and only 2 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
Share at 4+ pCi/L
24.2%
6.4 pts below MO
- DeKalb
- 24.2%
- Missouri
- 30.6%
33 tests, 2008 to 2017
Median result
2.3pCi/L
Below action level
- DeKalb
- 2.3 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
33
69th of 72 by tests
- DeKalb
- 33
- St. Louis
- 17,747
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
EPA predicts 2 to 4 pCi/L indoors
Rank in Missouri
52 of 72
Middle half
- DeKalb
- 24.2%
- Atchison
- 69.9%
By share, of 72 with 30+ tests
Read a result for DeKalb County
Starts at DeKalb County's median, 2.3 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.3 pCi/L
Between 2 and 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 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. DeKalb County's median reported result, 2008 to 2017.
The data
DeKalb County, At a glance
DeKalb County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
DeKalb County is a
USGS geologic potential: Moderate across 80% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for DeKalb County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 50.0% |
| 2016 | 0.0% |
| 2017 | 50.0% |
| 2018 | 0.0% |
| 2019 | 0.0% |
| 2020 | 0.0% |
| 2021 | 0.0% |
| 2023 | 0.0% |
2023: 0.0%. Across these years the share ran from 0.0% to 50.0%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 2 tests were reported to CDC for DeKalb 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).
DeKalb County, Compared
DeKalb County radon figures, compared
Calculated by Radon411DeKalb County's 33 reported tests over the 2008 to 2017 laboratory totals had a middle value of 2.3 pCi/L and a maximum of 21.8 pCi/L, and 24.2% reached 4 pCi/L. Missouri as a whole (115 Missouri counties, pooled) comes to 30.6%: 6.4 points higher than here.
The newest figure, in 2023, counts only 2 tests (0.0% at or above 4 pCi/L), too few to compare, so this reading uses the 33-test figure.
Among its state's counties it ranks 52nd of 72 Missouri counties with 30 or more tests for the same period. Statewide for the same period, Atchison County reported the highest share (69.9%) and Vernon County the lowest (8.8%).
Below the action level, 15 tests (45.5%) came in under 2 pCi/L, against 41.2% statewide, and 10 tests (30.3%) fell between 2 and 4, against 28.1% statewide. The busiest year on file was 2014, with 6 tests reported; the quietest, 2020, had 1.
EPA's 1993 zone map puts DeKalb County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 80% of the county's land moderate radon potential.
Next door, the shares run from 26.7% in Daviess County to 60.8% in Andrew County.
Pooled shares: Radon411's sum of CDC's county counts for one period.
DeKalb County, Geology
The ground under DeKalb County
PredictedMost of the ground under DeKalb County is one class on USGS's geologic map: 79.5% of its land is moderate radon potential, with 20.5% high. The map puts 79.5% of DeKalb County in the area it calls Dissected Till Plains and 20.5% in Northwestern Dissected Till Plains. USGS gives the first a radon index of 11, in the moderate band (9 to 11), and the second 13, in the high band (12 to 17).
| 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 | 79.5% |
| Northwestern Dissected Till Plains | Pennsylvanian shales covered by thick loess. | High | 13 | 20.5% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
DeKalb County beside the ground around it
DeKalb County has more high-potential ground than Missouri as a whole: 20.5% of its land against 8.2%. Of the 6 counties that border it, 3 have more high-potential ground, Buchanan County the most at 100%.
The map rates the ground, not the air in any home.
Local help
DeKalb County, Local resources
Radon testing and mitigation in DeKalb 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
DeKalb County, Questions
Questions about radon in DeKalb County
Are radon levels high in DeKalb County?
In 2023, 0.0% of the radon tests reported to CDC for DeKalb County, Missouri were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.6 pCi/L. Of 72 Missouri counties with 30 or more tests for the same period, 51 reported a higher share; pooled, the state comes to 30.6%.
Which counties border DeKalb County?
DeKalb County borders 6 counties: Clinton County, Andrew County, Daviess County, Gentry County, Buchanan County and Caldwell County.
Products
DeKalb County, Products
Testing a home in DeKalb County
In DeKalb County, 24.2% of 33 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 30.6% pooled across Missouri. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in DeKalb 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
MonitorAranet
Radon One battery digital radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- Alarm
- Screen, app
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
DeKalb County, Bordering counties
Counties bordering DeKalb County
Calculated by Radon411- Radon levels in Andrew CountyEPA zone 1
60.8%at or above 4 pCi/L
Median 4.9 pCi/L · 158 tests · 36.6 points above DeKalb County
- Radon levels in Buchanan CountyEPA zone 1
52.9%at or above 4 pCi/L
Median 4.2 pCi/L · 575 tests · 28.7 points above DeKalb County
- Radon levels in Gentry CountyEPA zone 2
41.7%at or above 4 pCi/L
Median 3.5 pCi/L · 24 tests · 17.5 points above DeKalb County
- Radon levels in Clinton CountyEPA zone 1
38.1%at or above 4 pCi/L
Median 2.8 pCi/L · 105 tests · 13.9 points above DeKalb County
- Radon levels in Daviess CountyEPA zone 2
26.7%at or above 4 pCi/L
Median 2.0 pCi/L · 30 tests · 2.5 points above DeKalb County
- Radon levels in Caldwell CountyEPA zone 2
6.3%at or above 4 pCi/L
Median 1.5 pCi/L · 16 tests · 17.9 points below DeKalb County
DeKalb County, Cities and towns
Cities and towns in DeKalb County
DeKalb County has been losing residents: from 11,605 in 2020 to 9,795 on July 1, 2025, a fall of 15.6% by the Census Bureau's estimates. That works out to 23 people per square mile of land. Cameron, the largest place on its list (7,341 residents in all), extends beyond DeKalb County, so no share of the total is worked out for it. Reported testing is thin here: 33 tests over 2008 to 2017, or 3.4 for every 1,000 residents (2025 estimate), where Missouri as a whole comes to 9.3.
From Cameron to Amity, CDC publishes no figure by town: each reads DeKalb County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Cameronextends beyond DeKalb County | 7,341 | −19.5% | Counted whole |
| Maysville | 1,071 | −1.3% | 10.9% |
| Stewartsville | 723 | −1.9% | 7.4% |
| Union Star | 372 | −2.1% | 3.8% |
| Osbornextends beyond DeKalb County | 369 | −0.8% | Counted whole |
| Clarksdale | 244 | −1.6% | 2.5% |
| Weatherby | 77 | −1.3% | 0.8% |
| Amity | 25 | −3.8% | 0.3% |
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 DeKalb County is counted whole, so it has no share.
DeKalb County, Homes
Homes in DeKalb County
Of DeKalb County's 4,277 homes, 75% are detached houses, against 70% across Missouri; 7% are mobile homes. Half of its homes were built before 1982, close to Missouri's 1978: 27% date from before 1960 and 24% from 2000 or later. 72% 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 | DeKalb County | Missouri |
|---|---|---|
| Housing units | 4,277 | 2,809,501 |
| Detached houses | 75% | 70% |
| In buildings of 5 or more | 6% | 13% |
| Mobile homes | 7% | 5% |
| Built before 1960 | 27% | 28% |
| Built since 2000 | 24% | 21% |
| Middle year built | 1982 | 1978 |
| Owner-occupied | 72% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.