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 Howell County, Missouri
EPA puts Howell 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
Share at 4+ pCi/L
46.8%
15.1 pts above MO
- Howell
- 46.8%
- Missouri
- 31.7%
158 tests, 2006 to 2015
Median result
3.7pCi/L
Below action level
- Howell
- 3.7 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2006 to 2015
Tests reported
158
26th of 71 by tests
- Howell
- 158
- St. Louis
- 14,426
Reported to CDC before any fix, 2006 to 2015
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
7 of 71
Top quarter
- Howell
- 46.8%
- Holt
- 70.0%
By share, of 71 with 30+ tests
Read a result for Howell County
Starts at Howell County's median, 3.7 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 3.7 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. Howell County's median reported result, 2006 to 2015.
The data
Howell County, At a glance
Howell County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Howell 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 Howell County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 25.0% |
| 2015 | 20.0% |
| 2016 | 62.5% |
| 2017 | 50.0% |
| 2018 | 87.5% |
| 2019 | 33.3% |
| 2020 | 66.7% |
| 2021 | 50.0% |
| 2022 | 20.0% |
| 2023 | 0.0% |
2023: 0.0%. Across these years the share ran from 0.0% to 87.5%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 1 test was reported to CDC for Howell 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).
Howell County, Compared
Howell County radon figures, compared
Calculated by Radon411In Howell County, about 5 in 10 reported tests over the 2006 to 2015 laboratory totals (74 of 158) were at or above EPA's action level. Against the national pool of 36.3%, the gap is 10.5 points higher. Across 115 Missouri counties pooled together, 31.7% of tests reached that level, so Howell County runs 15.1 points above its state.
The newest figure, in 2023, counts only 1 test (0.0% at or above 4 pCi/L), too few to compare, so this reading uses the 158-test figure.
Texas County, the one bordering county with a figure for the same period, reported 22.6%. By share, Howell County is 7th of 71 Missouri counties with 30 or more tests for the same period.
Half the tests came in under 3.7 pCi/L and half over it; the single highest reached 45.1 pCi/L. Below the action level, 43 tests (27.2%) came in under 2 pCi/L, against 40.6% statewide, and 41 tests (25.9%) fell between 2 and 4, against 27.7% statewide.
Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 46.8% share point the same way here. USGS geology rates 100% of the county's land moderate radon potential. CDC also counts 9 tests taken after mitigation in Howell County for the same period: tests in homes where a fix was already in.
The busiest year on file was 2017, with 14 tests reported; the quietest, 2023, had 1.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Howell County, Geology
The ground under Howell County
PredictedUSGS's geologic map puts all of Howell 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 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Howell County beside the ground around it
Across Missouri 8.2% of the land is rated high; none of Howell County's is. Of the 6 counties that border it, none has as large a share of moderate-potential ground; Oregon County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Howell County, Local resources
Radon testing and mitigation in Howell 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
Howell County, Questions
Questions about radon in Howell County
Are radon levels high in Howell County?
In 2023, 0.0% of the radon tests reported to CDC for Howell County, Missouri were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.0 pCi/L. Of 71 Missouri counties with 30 or more tests for the same period, 6 reported a higher share; pooled, the state comes to 31.7%.
Which counties border Howell County?
Howell County borders 6 counties: Fulton County, AR, Oregon County, MO, Ozark County, MO, Douglas County, MO, Shannon County, MO and Texas County, MO.
Products
Howell County, Products
Testing a home in Howell County
In Howell County, 46.8% of 158 tests reported to CDC over the 2006 to 2015 laboratory totals reached 4 pCi/L, against 31.7% pooled across Missouri. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Howell 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
Howell County, Bordering counties
Counties bordering Howell County
Calculated by Radon411- Radon levels in Fulton County, AREPA zone 2
66.7%at or above 4 pCi/L
Median 9.6 pCi/L · 3 tests · 19.9 points above Howell County
- Radon levels in Shannon County, MOEPA zone 2
26.3%at or above 4 pCi/L
Median 1.3 pCi/L · 19 tests · 20.5 points below Howell County
- Radon levels in Ozark County, MOEPA zone 2
25.0%at or above 4 pCi/L
Median 0.4 pCi/L · 8 tests · 21.8 points below Howell County
- Radon levels in Texas County, MOEPA zone 2
22.6%at or above 4 pCi/L
Median 1.4 pCi/L · 53 tests · 24.2 points below Howell County
- Radon levels in Oregon County, MOEPA zone 2
0.0%at or above 4 pCi/L
Median 2.0 pCi/L · 1 test · 46.8 points below Howell County
- Radon levels in Douglas County, MOEPA zone 2
0.0%at or above 4 pCi/L
Median 2.1 pCi/L · 2 tests · 46.8 points below Howell County
Howell County, Cities and towns
Cities and towns in Howell County
The Census Bureau estimates 40,798 residents in Howell County for July 1, 2025, 998 more than in 2020 (+2.5%). That works out to 44 people per square mile of land. Its largest town, West Plains, has 12,780 residents, 31.3% of the total. Together its 4 incorporated places hold 43.6% of those residents; the other 56.4% live outside any of them. Reported testing is thin here: 158 tests over 2006 to 2015, or 3.9 for every 1,000 residents (2025 estimate), where Missouri as a whole comes to 7.7.
From West Plains to Brandsville, CDC publishes no figure by town: each reads Howell County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| West Plains | 12,780 | +4.7% | 31.3% |
| Mountain View | 2,661 | +1.3% | 6.5% |
| Willow Springs | 2,211 | +1.8% | 5.4% |
| Brandsville | 129 | +1.6% | 0.3% |
4 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).
Howell County, Homes
Homes in Howell County
Howell County is a place of houses on their own lots: 75% of its 18,104 homes are detached single-family houses, against 70% across Missouri. Half of its homes were built before 1983, close to Missouri's 1978: 21% date from before 1960 and 24% from 2000 or later. 69% 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 | Howell County | Missouri |
|---|---|---|
| Housing units | 18,104 | 2,809,501 |
| Detached houses | 75% | 70% |
| In buildings of 5 or more | 4% | 13% |
| Mobile homes | 13% | 5% |
| Built before 1960 | 21% | 28% |
| Built since 2000 | 24% | 21% |
| Middle year built | 1983 | 1978 |
| Owner-occupied | 69% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.