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 Posey County, Indiana
EPA puts Posey County in Zone 2, its middle radon zone, and 35.3% of its 215 reported radon tests (2008 to 2017, laboratory totals) were at or above 4 pCi/L. Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
35.3%
3.6 pts below IN
- Posey
- 35.3%
- Indiana
- 38.9%
215 tests, 2008 to 2017
Median result
2.8pCi/L
Below action level
- Posey
- 2.8 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
215
29th of 69 by tests
- Posey
- 215
- St. Joseph
- 7,346
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 Indiana
51 of 69
Middle half
- Posey
- 35.3%
- Miami
- 63.3%
By share, of 69 with 30+ tests
Read a result for Posey County
Starts at Posey County's median, 2.8 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.8 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. Posey County's median reported result, 2008 to 2017.
The data
Posey County, At a glance
Posey County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Posey 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 Posey County, 2008 to 2017, laboratory
Under 2 pCi/L: 25%2 to 4 pCi/L: 40%4 pCi/L and above: 35%
Of 215 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 53 | 24.7% |
| 2 to 4 pCi/L | 86 | 40.0% |
| 4 pCi/L and above | 76 | 35.3% |
What these figures count
These are the 215 tests reported to CDC for Posey County over 2008 to 2017 (laboratory totals), many from homes being sold or already suspected of a problem: they describe the county's reported tests, not this house.
Measured: CDC tracking data. Figure above: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).
Posey County, Compared
Posey County radon figures, compared
Calculated by Radon411In Posey County, about 4 in 10 reported tests over the 2008 to 2017 laboratory totals (76 of 215) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 0.4 points lower. Across 92 Indiana counties pooled together, 38.9% of tests reached that level, so Posey County runs 3.6 points below its state.
Of 4 neighbours with a figure, 1 reported a larger share at or above 4 pCi/L and 3 a smaller one; the spread is 24.1% (Henderson County, KY) to 43.3% (Gibson County). By share, Posey County is 51st of 69 Indiana counties with 30 or more tests for the same period.
Half the tests came in under 2.8 pCi/L and half over it; the single highest reached 17.9 pCi/L. Below the action level, 53 tests (24.7%) came in under 2 pCi/L, against 32.8% statewide, and 86 tests (40.0%) fell between 2 and 4, against 28.3% statewide.
Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 35.3% share point the same way here. USGS geology rates 100% of the county's land moderate radon potential. CDC also counts 19 tests taken after mitigation in Posey County for the same period: tests in homes where a fix was already in.
CDC's ten-year totals for Posey County went from 152 tests (2005 to 2014) to 215 (2008 to 2017), the share going from 36.8% to 35.3%.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Posey County, Geology
The ground under Posey County
PredictedUSGS's geologic map puts all of Posey County's mapped land in one class: moderate radon potential. 98.2% of it lies in the area the map calls Wabash Lowland, to which USGS gives a radon index of 10, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Wabash Lowland | Loess, pre-Wisconsinan glacial deposits, Pennsylvanian shale, sandstone, and carbonate bedrock. | Moderate | 10 | 98.2% |
| Shawnee Hills Section | Unglaciated Ordovician to Pennsylvanian limestone, sandstone, and shale. | Moderate | 10 | 1.1% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Posey County beside the ground around it
Across Indiana 56.6% of the land is rated high; none of Posey County's is. Of the 6 counties that border it, none has as large a share of moderate-potential ground; Henderson County, KY comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Posey County, Local resources
Radon testing and mitigation in Posey County
- Indiana's radon programIndiana Department of HealthIndiana's radon program licenses or certifies radon professionals and offers free or discounted test kits, and answers questions about testing and mitigation in Indiana.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
To purchase a low-cost radon short term or long term test kit, please visit the American Lung Association
- Compare kits
- Professionals in Indiana17 professionals are listed in Indiana.
What Indiana's program says
- Phone
- 1-800-272-9723
- Licensing of radon professionals
According to the Indiana Radon Rule, 410 IAC 5.1, everyone who is serving Indiana by doing radon testing, analysis and mitigation (radon reduction) in residential structures must be certified by the Indiana State Department of Health.
What it means
Posey County, Questions
Questions about radon in Posey County
Are radon levels high in Posey County?
Over the 2008 to 2017 laboratory totals, 35.3% of the radon tests reported to CDC for Posey County, Indiana were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.8 pCi/L. Of 69 Indiana counties with 30 or more tests for the same period, 50 reported a higher share; pooled, the state comes to 38.9%.
Which counties border Posey County?
Posey County borders 6 counties: Vanderburgh County, IN, White County, IL, Henderson County, KY, Union County, KY, Gibson County, IN and Gallatin County, IL.
Products
Posey County, Products
Testing a home in Posey County
In Posey County, 35.3% of 215 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 38.9% pooled across Indiana. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Posey 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
RadonScan USB-powered radon monitor with a color screen
- C-NRPP 2024/25: Not included
- Plug-in
- Alarm
- Screen
First reading: Within 5 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Posey County, Bordering counties
Counties bordering Posey County
Calculated by Radon411- Radon levels in Gibson County, INEPA zone 2
43.3%at or above 4 pCi/L
Median 3.4 pCi/L · 120 tests · 8.0 points above Posey County
- Radon levels in Gallatin County, ILEPA zone 2
33.3%at or above 4 pCi/L
Median 2.0 pCi/L · 6 tests · 2.0 points below Posey County
- Radon levels in White County, ILEPA zone 2
29.4%at or above 4 pCi/L
Median 2.9 pCi/L · 34 tests · 5.9 points below Posey County
- Radon levels in Union County, KYEPA zone 2
25.0%at or above 4 pCi/L
Median 1.6 pCi/L · 8 tests · 10.3 points below Posey County
- Radon levels in Vanderburgh County, INEPA zone 2
24.4%at or above 4 pCi/L
Median 2.4 pCi/L · 1,505 tests · 10.9 points below Posey County
- Radon levels in Henderson County, KYEPA zone 2
24.1%at or above 4 pCi/L
Median 2.3 pCi/L · 54 tests · 11.2 points below Posey County
Posey County, Cities and towns
Cities and towns in Posey County
About 24,988 people live in Posey County by the Census Bureau's estimate for July 1, 2025, 202 fewer than in 2020 (−0.8%). That works out to 61 people per square mile of land. Its largest town, Mount Vernon, has 6,289 residents, 25.2% of the total. Together its 5 incorporated places hold 34.5% of those residents; the other 65.5% live outside any of them. CDC's 215 reported tests for 2008 to 2017 work out to 8.6 per 1,000 residents (2025 estimate), close to Indiana's 6.2.
From Mount Vernon to Griffin, CDC publishes no figure by town: each reads Posey County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Mount Vernon | 6,289 | −2.9% | 25.2% |
| Poseyville | 966 | −0.3% | 3.9% |
| New Harmony | 680 | −1.9% | 2.7% |
| Cynthiana | 552 | −0.4% | 2.2% |
| Griffin | 139 | −1.4% | 0.6% |
5 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).
Posey County, Homes
Homes in Posey County
Posey County is a place of houses on their own lots: 83% of its 11,081 homes are detached single-family houses, against 73% across Indiana. Half of its homes were built before 1976, close to Indiana's 1976: 27% date from before 1960 and 17% from 2000 or later. Owners live in 82% of the occupied homes (Indiana: 70%), so for most households a test and a fix are their own to order.
| Homes | Posey County | Indiana |
|---|---|---|
| Housing units | 11,081 | 2,953,344 |
| Detached houses | 83% | 73% |
| In buildings of 5 or more | 6% | 13% |
| Mobile homes | 7% | 4% |
| Built before 1960 | 27% | 32% |
| Built since 2000 | 17% | 21% |
| Middle year built | 1976 | 1976 |
| Owner-occupied | 82% | 70% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.