Short-term kitFirst Alert
RD1 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 2 to 4 days
Locations and reports
Radon Levels in Douglas County, Missouri
EPA puts Douglas 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
45.7%
Howell County
- Howell
- 45.7%
- Texas
- 19.3%
5 of 7 neighbours have 30+ tests, 2008 to 2017
Nearest county
20.4%
Webster County, 32 miles
- Webster
- 20.4%
- Missouri
- 30.6%
Share at 4+ pCi/L, 103 tests, 2008 to 2017
Ground above low
100.0%
5.8 pts above Missouri
- Douglas
- 100.0%
- Missouri
- 94.2%
Share of land USGS rates moderate or high potential
Tests reported
3
Too few for a share
- Douglas
- 3
- Needed
- 30
2022
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 Douglas 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
Douglas County, At a glance
Douglas County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Douglas 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 Douglas County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 100.0% |
| 2015 | 0.0% |
| 2016 | 0.0% |
| 2018 | 100.0% |
| 2022 | 66.7% |
| 2023 | 0.0% |
2023: 0.0%. 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 Douglas 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).
Douglas County, Compared
Douglas County radon figures, compared
Calculated by Radon411CDC's largest figure for Douglas County rests on 3 tests in 2022, 2 of them at or above 4 pCi/L, so each test moves its share by 33.3 points and no rank or comparison is drawn from it. Results reached as high as 28.8 pCi/L, with a middle value of 7.8 pCi/L.
Of the counties bordering it, 5 have a figure over the 2008 to 2017 laboratory totals: Howell County reported the largest share at or above 4 pCi/L, 45.7%, and Texas County the smallest, 19.3%, with Taney County at 37.0%, Christian County at 31.7% and Webster County at 20.4% between. Farther out, Laclede County (50 miles away) at 37.0%, Greene County (52 miles away) at 32.7% and Stone County (55 miles away) at 41.6% 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 Douglas 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.
Douglas County, Geology
The ground under Douglas County
PredictedUSGS's geologic map puts all of Douglas County's mapped land in one class: moderate radon potential. All of it lies in the area the map calls Salem Plateau, 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 |
|---|---|---|---|---|
| Salem Plateau | Ordovician dolomite, sandstone, limestone, and shale. | Moderate | 11 | 99.6% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Douglas County beside the ground around it
Across Missouri 8.2% of the land is rated high; none of Douglas County's is. Of the 7 counties that border it, none has as large a share of moderate-potential ground; Christian County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Douglas County, Local resources
Radon testing and mitigation in Douglas 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
Douglas County, Questions
Questions about radon in Douglas County
Are radon levels high in Douglas County?
In 2023, 0.0% of the radon tests reported to CDC for Douglas County, Missouri were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.8 pCi/L. Of the counties bordering it, 5 have a figure over the 2008 to 2017 laboratory totals: Howell County reported the largest share at or above 4 pCi/L, 45.7%, and Texas County the smallest, 19.3%, with Taney County at 37.0%, Christian County at 31.7% and Webster County at 20.4% between.
Which counties border Douglas County?
Douglas County borders 7 counties: Ozark County, Wright County, Christian County, Webster County, Taney County, Howell County and Texas County.
Products
Douglas County, Products
Testing a home in Douglas County
No CDC figure names Douglas County; the nearest county with one, Webster County (32 miles away), reported 20.4% 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 Douglas 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
Monitor
View Plus radon and air quality monitor
- C-NRPP 2024/25: Approved
- Battery
- Wi-Fi, Bluetooth
- Screen, app
Method: Alpha spectrometry
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Douglas County, Bordering counties
Counties bordering Douglas County
Calculated by Radon411- Radon levels in Ozark CountyEPA zone 2
50.0%at or above 4 pCi/L
Median 4.7 pCi/L · 4 tests
- Radon levels in Howell CountyEPA zone 2
45.7%at or above 4 pCi/L
Median 3.5 pCi/L · 138 tests
- Radon levels in Taney CountyEPA zone 2
37.0%at or above 4 pCi/L
Median 3.0 pCi/L · 146 tests
- Radon levels in Christian CountyEPA zone 2
31.7%at or above 4 pCi/L
Median 1.9 pCi/L · 436 tests
- Radon levels in Wright CountyEPA zone 2
27.8%at or above 4 pCi/L
Median 2.7 pCi/L · 18 tests
- Radon levels in Webster CountyEPA zone 2
20.4%at or above 4 pCi/L
Median 1.6 pCi/L · 103 tests
- Radon levels in Texas CountyEPA zone 2
19.3%at or above 4 pCi/L
Median 1.3 pCi/L · 57 tests
Douglas County, Cities and towns
Cities and towns in Douglas County
Douglas County is growing: the Census Bureau puts it at 12,342 residents on July 1, 2025, up 6.4% from 11,604 in 2020. That works out to 15 people per square mile of land. Ava, its one incorporated place, has 3,231 residents, 26.2% of the total. Reported testing is thin here: 3 tests over 2022, or 0.2 for every 1,000 residents (2025 estimate), where Missouri as a whole comes to 0.4.
Ava is the one incorporated place here; CDC publishes no figure by town, so it reads Douglas County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Ava | 3,231 | +11.1% | 26.2% |
One incorporated place, 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).
Douglas County, Homes
Homes in Douglas County
Douglas County is a place of houses on their own lots: 81% of its 5,397 homes are detached single-family houses, against 70% across Missouri. Half of its homes were built before 1985, close to Missouri's 1978: 22% date from before 1960 and 25% from 2000 or later. Owners live in 79% of the occupied homes (Missouri: 68%), so for most households a test and a fix are their own to order.
| Homes | Douglas County | Missouri |
|---|---|---|
| Housing units | 5,397 | 2,809,501 |
| Detached houses | 81% | 70% |
| In buildings of 5 or more | 1% | 13% |
| Mobile homes | 16% | 5% |
| Built before 1960 | 22% | 28% |
| Built since 2000 | 25% | 21% |
| Middle year built | 1985 | 1978 |
| Owner-occupied | 79% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.