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
Locations and reports
Radon Levels in Shelby County, Ohio
EPA puts Shelby County in Zone 1, its highest radon zone, and high results are common there: 60.1% of the 248 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
60.1%
7.8 pts above OH
- Shelby
- 60.1%
- Ohio
- 52.3%
248 tests, 2008 to 2017
Median result
5.2pCi/L
Action level reached
- Shelby
- 5.2 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
248
52nd of 79 by tests
- Shelby
- 248
- 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
25 of 79
Middle half
- Shelby
- 60.1%
- Pickaway
- 81.4%
By share, of 79 with 30+ tests
Read a result for Shelby County
Starts at Shelby County's median, 5.2 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 5.2 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. Shelby County's median reported result, 2008 to 2017.
The data
Shelby County, At a glance
Shelby County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Shelby 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 Shelby County, 2008 to 2017, laboratory
Under 2 pCi/L: 17%2 to 4 pCi/L: 23%4 pCi/L and above: 60%
Of 248 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 43 | 17.3% |
| 2 to 4 pCi/L | 56 | 22.6% |
| 4 pCi/L and above | 149 | 60.1% |
What these figures count
These are the 248 tests reported to CDC for Shelby 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).
Shelby County, Compared
Shelby County radon figures, compared
Calculated by Radon411More than half: 60.1% of the 248 radon tests reported to CDC for Shelby County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 25th of 79 Ohio counties with 30 or more tests for the same period. That is 7.8 points above the 52.3% pooled from 88 Ohio counties.
The median result, 5.2 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 40.1 pCi/L. The rest split 17.3% under 2 pCi/L and 22.6% from 2 to 4 (Ohio: 23.1% and 24.6%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 60.1% share point the same way here.
5 of its 6 bordering counties with figures ran higher, led by Logan County at 73.6%; Mercer County reported 57.7%. 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 Shelby County went from 442 tests (2005 to 2014) to 248 (2008 to 2017), the share going from 51.6% to 60.1%.
Nationally, every county with a figure for the same period pools to 35.7%; Shelby County sits 24.4 points above it. CDC also counts 10 tests taken after mitigation in Shelby 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.
Shelby County, Geology
The ground under Shelby County
PredictedUSGS's geologic map puts all of Shelby 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.
Shelby County beside the ground around it
Shelby County has more high-potential ground than Ohio as a whole: 100% of its land against 62.8%. Of the 6 counties that border it, none has as large a share of high-potential ground; Auglaize County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Shelby County, Local resources
Radon testing and mitigation in Shelby 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
Shelby County, Questions
Questions about radon in Shelby County
Are radon levels high in Shelby County?
Over the 2008 to 2017 laboratory totals, 60.1% of the radon tests reported to CDC for Shelby County, Ohio were at or above 4 pCi/L, and the median reported pre-mitigation result was 5.2 pCi/L. Of 79 Ohio counties with 30 or more tests for the same period, 24 reported a higher share; pooled, the state comes to 52.3%.
Which counties border Shelby County?
Shelby County borders 6 counties: Auglaize County, Miami County, Mercer County, Logan County, Darke County and Champaign County.
Products
Shelby County, Products
Testing a home in Shelby County
In Shelby County, 60.1% of 248 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 Shelby 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
RadonScan-Plus USB-powered radon monitor with Wi-Fi
- C-NRPP 2024/25: Not included
- Plug-in
- Wi-Fi
- Alarm
- Screen, app
First reading: Within 5 minutes
Short-term kit
RA100 short-term liquid scintillation radon test kit
- Lab fee extra
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
Shelby County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Shelby County
Explore
Shelby County, Bordering counties
Counties bordering Shelby County
Calculated by Radon411- Radon levels in Logan CountyEPA zone 1
73.6%at or above 4 pCi/L
Median 7.9 pCi/L · 755 tests · 13.5 points above Shelby County
- Radon levels in Auglaize CountyEPA zone 1
71.2%at or above 4 pCi/L
Median 6.5 pCi/L · 139 tests · 11.1 points above Shelby County
- Radon levels in Champaign CountyEPA zone 1
71.1%at or above 4 pCi/L
Median 6.8 pCi/L · 596 tests · 11.0 points above Shelby County
- Radon levels in Miami CountyEPA zone 1
65.2%at or above 4 pCi/L
Median 6.1 pCi/L · 690 tests · 5.1 points above Shelby County
- Radon levels in Darke CountyEPA zone 1
63.7%at or above 4 pCi/L
Median 5.6 pCi/L · 270 tests · 3.6 points above Shelby County
- Radon levels in Mercer CountyEPA zone 1
57.7%at or above 4 pCi/L
Median 5.1 pCi/L · 149 tests · 2.4 points below Shelby County
Shelby County, Cities and towns
Cities and towns in Shelby County
Shelby County's population has barely moved since 2020: 48,065 residents on July 1, 2025 against 48,158 then, by the Census Bureau's estimates. That works out to 118 people per square mile of land. Its largest town, Sidney, has 20,124 residents, 41.9% of the total. Reported testing is thin here: 248 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 Sidney to Lockington, CDC publishes no figure by town: each reads Shelby County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Sidney | 20,124 | −2.0% | 41.9% |
| Minsterextends beyond Shelby County | 3,062 | −1.3% | Counted whole |
| Fort Loramie | 1,736 | +8.4% | 3.6% |
| Anna | 1,566 | +6.5% | 3.3% |
| Jackson Center | 1,446 | +0.5% | 3.0% |
| Botkins | 1,133 | −2.0% | 2.4% |
| Russia | 811 | +12.5% | 1.7% |
| Port Jefferson | 338 | +7.3% | 0.7% |
| Kettlersville | 176 | +6.0% | 0.4% |
| Lockington | 164 | +6.5% | 0.3% |
10 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 Shelby County is counted whole, so it has no share.
Shelby County, Homes
Homes in Shelby County
Shelby County is a place of houses on their own lots: 78% of its 20,113 homes are detached single-family houses, against 69% across Ohio. Half of its homes were built before 1974, close to Ohio's 1970: 35% date from before 1960 and 15% from 2000 or later. 74% of occupied homes are lived in by their owner (Ohio: 67%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Shelby County | Ohio |
|---|---|---|
| Housing units | 20,113 | 5,271,573 |
| Detached houses | 78% | 69% |
| In buildings of 5 or more | 6% | 15% |
| Mobile homes | 4% | 4% |
| Built before 1960 | 35% | 38% |
| Built since 2000 | 15% | 16% |
| Middle year built | 1974 | 1970 |
| Owner-occupied | 74% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.