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 Ste. Genevieve County, Missouri
EPA puts Ste. Genevieve County in Zone 2, its middle radon zone, and only 3 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
31.1%
0.5 pts above MO
- Ste. Genevieve
- 31.1%
- Missouri
- 30.6%
74 tests, 2008 to 2017
Median result
2.5pCi/L
Below action level
- Ste. Genevieve
- 2.5 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
74
46th of 72 by tests
- Ste. Genevieve
- 74
- 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
37 of 72
Middle half
- Ste. Genevieve
- 31.1%
- Atchison
- 69.9%
By share, of 72 with 30+ tests
Read a result for Ste. Genevieve County
Starts at Ste. Genevieve County's median, 2.5 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.5 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. Ste. Genevieve County's median reported result, 2008 to 2017.
The data
Ste. Genevieve County, At a glance
Ste. Genevieve County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Ste. Genevieve 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 Ste. Genevieve County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 20.0% |
| 2015 | 40.0% |
| 2016 | 33.3% |
| 2017 | 42.9% |
| 2019 | 0.0% |
| 2020 | 0.0% |
| 2021 | 66.7% |
| 2022 | 28.6% |
| 2023 | 66.7% |
2023: 66.7%. Across these years the share ran from 0.0% to 66.7%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 3 tests were reported to CDC for Ste. Genevieve 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).
Ste. Genevieve County, Compared
Ste. Genevieve County radon figures, compared
Calculated by Radon411In Ste. Genevieve County, about 3 in 10 reported tests over the 2008 to 2017 laboratory totals (23 of 74) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 4.6 points lower. Across 115 Missouri counties pooled together, 30.6% of tests reached that level, so Ste. Genevieve County runs 0.5 points above its state.
The newest figure, in 2023, counts only 3 tests (66.7% at or above 4 pCi/L), too few to compare, so this reading uses the 74-test figure.
Of 5 neighbours with a figure, all 5 reported a larger share at or above 4 pCi/L; the spread is 37.8% (Perry County) to 44.2% (Monroe County, IL). By share, Ste. Genevieve County is 37th of 72 Missouri counties with 30 or more tests for the same period.
Half the tests came in under 2.5 pCi/L and half over it; the single highest reached 36.3 pCi/L. Below the action level, 28 tests (37.8%) came in under 2 pCi/L, against 41.2% statewide, and 23 tests (31.1%) fell between 2 and 4, against 28.1% statewide.
Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 31.1% share point the same way here. USGS geology rates 100% of the county's land moderate radon potential.
The busiest year on file was 2017, with 14 tests reported; the quietest, 2020, had 1.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Ste. Genevieve County, Geology
The ground under Ste. Genevieve County
PredictedUSGS's geologic map puts all of Ste. Genevieve 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.
Ste. Genevieve County beside the ground around it
Across Missouri 8.2% of the land is rated high; none of Ste. Genevieve County's is. Of the 5 counties that border it, 1 has more high-potential ground, St. Francois County the most at 31.2%.
The map rates the ground, not the air in any home.
Local help
Ste. Genevieve County, Local resources
Radon testing and mitigation in Ste. Genevieve 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
Ste. Genevieve County, Questions
Questions about radon in Ste. Genevieve County
Are radon levels high in Ste. Genevieve County?
In 2023, 66.7% of the radon tests reported to CDC for Ste. Genevieve County, Missouri were at or above 4 pCi/L, and the median reported pre-mitigation result was 5.6 pCi/L. Of 72 Missouri counties with 30 or more tests for the same period, 36 reported a higher share; pooled, the state comes to 30.6%.
Which counties border Ste. Genevieve County?
Ste. Genevieve County borders 5 counties: St. Francois County, MO, Randolph County, IL, Perry County, MO, Monroe County, IL and Jefferson County, MO.
Products
Ste. Genevieve County, Products
Testing a home in Ste. Genevieve County
In Ste. Genevieve County, 31.1% of 74 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 Ste. Genevieve County; a long-term test tells the year-round average.
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
Monitor
Wave Radon battery smart radon monitor
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- App only
Method: Alpha spectrometry
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Best radon monitors for Ste. Genevieve County homes, compared
Explore
Ste. Genevieve County, Bordering counties
Counties bordering Ste. Genevieve County
Calculated by Radon411- Radon levels in Monroe County, ILEPA zone 2
44.2%at or above 4 pCi/L
Median 3.5 pCi/L · 1,021 tests · 13.1 points above Ste. Genevieve County
- Radon levels in Jefferson County, MOEPA zone 2
41.6%at or above 4 pCi/L
Median 3.1 pCi/L · 2,652 tests · 10.5 points above Ste. Genevieve County
- Radon levels in St. Francois County, MOEPA zone 2
41.1%at or above 4 pCi/L
Median 2.9 pCi/L · 146 tests · 10.0 points above Ste. Genevieve County
- Radon levels in Randolph County, ILEPA zone 2
40.3%at or above 4 pCi/L
Median 3.2 pCi/L · 134 tests · 9.2 points above Ste. Genevieve County
- Radon levels in Perry County, MOEPA zone 2
37.8%at or above 4 pCi/L
Median 3.2 pCi/L · 82 tests · 6.7 points above Ste. Genevieve County
Ste. Genevieve County, Cities and towns
Cities and towns in Ste. Genevieve County
The Census Bureau estimates 18,689 residents in Ste. Genevieve County for July 1, 2025, 209 more than in 2020 (+1.1%). That works out to 37 people per square mile of land. Its largest town, Ste. Genevieve, has 5,065 residents, 27.1% of the total. Together its 3 incorporated places hold 32.4% of those residents; the other 67.6% live outside any of them. Reported testing is thin here: 74 tests over 2008 to 2017, or 4.0 for every 1,000 residents (2025 estimate), where Missouri as a whole comes to 9.3.
From Ste. Genevieve to St. Mary, CDC publishes no figure by town: each reads Ste. Genevieve County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Ste. Genevieve | 5,065 | +1.3% | 27.1% |
| Bloomsdale | 683 | +6.6% | 3.7% |
| St. Mary | 312 | +1.0% | 1.7% |
3 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).
Ste. Genevieve County, Homes
Homes in Ste. Genevieve County
Ste. Genevieve County is a place of houses on their own lots: 80% of its 8,323 homes are detached single-family houses, against 70% across Missouri. Half of its homes were built before 1981, close to Missouri's 1978: 21% date from before 1960 and 20% from 2000 or later. Owners live in 82% of the occupied homes (Missouri: 68%), so for most households a test and a fix are their own to order.
| Homes | Ste. Genevieve County | Missouri |
|---|---|---|
| Housing units | 8,323 | 2,809,501 |
| Detached houses | 80% | 70% |
| In buildings of 5 or more | 5% | 13% |
| Mobile homes | 12% | 5% |
| Built before 1960 | 21% | 28% |
| Built since 2000 | 20% | 21% |
| Middle year built | 1981 | 1978 |
| Owner-occupied | 82% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.