Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
Locations and reports
Radon Levels in Preble County, Ohio
EPA puts Preble County in Zone 1, its highest radon zone, and high results are common there: 62.7% of the 212 radon tests reported to CDC (2008 to 2017, laboratory totals) came back 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
62.7%
10.4 pts above OH
- Preble
- 62.7%
- Ohio
- 52.3%
212 tests, 2008 to 2017
Median result
5.5pCi/L
Action level reached
- Preble
- 5.5 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
212
54th of 79 by tests
- Preble
- 212
- Franklin
- 16,142
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in Ohio
19 of 79
Top quarter
- Preble
- 62.7%
- Pickaway
- 81.4%
By share, of 79 with 30+ tests
Read a result for Preble County
Starts at Preble County's median, 5.5 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 5.5 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. Preble County's median reported result, 2008 to 2017.
The data
Preble County, At a glance
Preble County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Preble County in
USGS geologic potential: High across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Preble County, 2008 to 2017, laboratory
Under 2 pCi/L: 16%2 to 4 pCi/L: 21%4 pCi/L and above: 63%
Of 212 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 35 | 16.5% |
| 2 to 4 pCi/L | 44 | 20.8% |
| 4 pCi/L and above | 133 | 62.7% |
What these figures count
These are the 212 tests reported to CDC for Preble 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).
Preble County, Compared
Preble County radon figures, compared
Calculated by Radon411More than half: 62.7% of the 212 radon tests reported to CDC for Preble County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 19th of 79 Ohio counties with 30 or more tests for the same period. That is 10.4 points above the 52.3% pooled from 88 Ohio counties.
The median result, 5.5 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 71.1 pCi/L. The rest split 16.5% under 2 pCi/L and 20.8% from 2 to 4 (Ohio: 23.1% and 24.6%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 62.7% share point the same way here.
1 of its 4 bordering counties with figures ran higher, led by Darke County at 63.7%; Montgomery County reported 50.3%. Statewide for the same period, Pickaway County reported the highest share (81.4%) and Cuyahoga County the lowest (21.7%).
CDC's ten-year totals for Preble County went from 295 tests (2005 to 2014) to 212 (2008 to 2017), the share going from 60.7% to 62.7%.
Nationally, every county with a figure for the same period pools to 35.7%; Preble County sits 27.0 points above it. CDC also counts 8 tests taken after mitigation in Preble County for the same period: tests in homes where a fix was already in.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Preble County, Geology
The ground under Preble County
PredictedUSGS's geologic map puts all of Preble County's mapped land in one class: high radon potential. All of it lies in the area the map calls Till Plains, to which USGS gives a radon index of 14, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Till Plains | Glacial deposits underlain by Ordovician through Devonian limestone and shale. | High | 14 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Preble County beside the ground around it
Preble County has more high-potential ground than Ohio as a whole: 100% of its land against 62.8%. Of the 5 counties that border it, none has as large a share of high-potential ground; Darke County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Preble County, Local resources
Radon testing and mitigation in Preble County
- Radon Education and Licensing ProgramRadon Education and Licensing Program, run by Ohio Department of Health, licenses or certifies radon professionals and offers free or discounted test kits, and answers questions about testing and mitigation in Ohio.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Free radon test kits are available for Ohio homeowners.
- Compare kits
- Professionals in Ohio479 professionals are listed in Ohio.
What Ohio's program says
- Phone
- 614-728-0272
- indoor.radon@odh.ohio.gov
- Licensing of radon professionals
This program licenses companies and persons directly involved with the radon testing and mitigation industry.
What it means
Preble County, Questions
Questions about radon in Preble County
Are radon levels high in Preble County?
Over the 2008 to 2017 laboratory totals, 62.7% of the radon tests reported to CDC for Preble County, Ohio were at or above 4 pCi/L, and the median reported pre-mitigation result was 5.5 pCi/L. Of 79 Ohio counties with 30 or more tests for the same period, 18 reported a higher share; pooled, the state comes to 52.3%.
Which counties border Preble County?
Preble County borders 5 counties: Union County, IN, Wayne County, IN, Montgomery County, OH, Darke County, OH and Butler County, OH.
Products
Preble County, Products
Testing a home in Preble County
In Preble County, 62.7% of 212 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 52.3% pooled across Ohio. In Zone 1 the year-round level in Preble County is the one to know: a long-term test (more than 90 days) or a monitor, with a short-term kit for a first answer.
Test kits and monitors3
See every kit and monitor
Monitor
Corentium Home battery digital radon detector
- C-NRPP 2024/25: Approved
- Battery
- Screen
Method: Alpha spectrometry
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
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Preble County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Preble County
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Preble County, Bordering counties
Counties bordering Preble County
Calculated by Radon411- Radon levels in Darke County, OHEPA zone 1
63.7%at or above 4 pCi/L
Median 5.6 pCi/L · 270 tests · 1.0 points above Preble County
- Radon levels in Wayne County, INEPA zone 1
56.4%at or above 4 pCi/L
Median 4.5 pCi/L · 140 tests · 6.3 points below Preble County
- Radon levels in Butler County, OHEPA zone 1
54.3%at or above 4 pCi/L
Median 4.4 pCi/L · 1,953 tests · 8.4 points below Preble County
- Radon levels in Montgomery County, OHEPA zone 1
50.3%at or above 4 pCi/L
Median 4.0 pCi/L · 2,922 tests · 12.4 points below Preble County
- Radon levels in Union County, INEPA zone 1
50.0%at or above 4 pCi/L
Median 3.8 pCi/L · 8 tests · 12.7 points below Preble County
Preble County, Cities and towns
Cities and towns in Preble County
About 40,664 people live in Preble County by the Census Bureau's estimate for July 1, 2025, 343 fewer than in 2020 (−0.8%). That works out to 96 people per square mile of land. Its largest town, Eaton, has 8,327 residents, 20.5% of the total. Reported testing is thin here: 212 tests over 2008 to 2017, or 5.2 for every 1,000 residents (2025 estimate), where Ohio as a whole comes to 8.3.
From Eaton to West Elkton, CDC publishes no figure by town: each reads Preble County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Eaton | 8,327 | −0.8% | 20.5% |
| Camden | 1,984 | −0.2% | 4.9% |
| Lewisburg | 1,734 | −1.0% | 4.3% |
| New Paris | 1,480 | −0.6% | 3.6% |
| West Alexandria | 1,311 | −1.1% | 3.2% |
| Gratis | 835 | −0.7% | 2.1% |
| Eldorado | 447 | −1.5% | 1.1% |
| West Manchester | 411 | −1.4% | 1.0% |
| Veronaextends beyond Preble County | 400 | −0.7% | Counted whole |
| College Cornerextends beyond Preble County | 398 | +1.8% | Counted whole |
| West Elkton | 156 | −1.3% | 0.4% |
11 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 Preble County is counted whole, so it has no share.
Preble County, Homes
Homes in Preble County
Preble County is a place of houses on their own lots: 87% of its 18,106 homes are detached single-family houses, against 69% across Ohio. Half of its homes were built before 1972, close to Ohio's 1970: 39% date from before 1960 and 13% from 2000 or later. Owners live in 79% of the occupied homes (Ohio: 67%), so for most households a test and a fix are their own to order.
| Homes | Preble County | Ohio |
|---|---|---|
| Housing units | 18,106 | 5,271,573 |
| Detached houses | 87% | 69% |
| In buildings of 5 or more | 3% | 15% |
| Mobile homes | 3% | 4% |
| Built before 1960 | 39% | 38% |
| Built since 2000 | 13% | 16% |
| Middle year built | 1972 | 1970 |
| Owner-occupied | 79% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.