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 Wyandot County, Ohio
EPA puts Wyandot County in Zone 1, its highest radon zone, and high results are common there: 46.3% of the 320 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
46.3%
6.0 pts below OH
- Wyandot
- 46.3%
- Ohio
- 52.3%
320 tests, 2008 to 2017
Median result
3.6pCi/L
Below action level
- Wyandot
- 3.6 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
320
46th of 79 by tests
- Wyandot
- 320
- 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
54 of 79
Middle half
- Wyandot
- 46.3%
- Pickaway
- 81.4%
By share, of 79 with 30+ tests
Read a result for Wyandot County
Starts at Wyandot County's median, 3.6 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 3.6 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. Wyandot County's median reported result, 2008 to 2017.
The data
Wyandot County, At a glance
Wyandot County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Wyandot 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 Wyandot County, 2008 to 2017, laboratory
Under 2 pCi/L: 24%2 to 4 pCi/L: 30%4 pCi/L and above: 46%
Of 320 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 76 | 23.8% |
| 2 to 4 pCi/L | 96 | 30.0% |
| 4 pCi/L and above | 148 | 46.3% |
What these figures count
These are the 320 tests reported to CDC for Wyandot 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).
Wyandot County, Compared
Wyandot County radon figures, compared
Calculated by Radon411In Wyandot County, about 5 in 10 reported tests over the 2008 to 2017 laboratory totals (148 of 320) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 10.6 points higher. Across 88 Ohio counties pooled together, 52.3% of tests reached that level, so Wyandot County runs 6.0 points below its state.
Of 5 neighbours with a figure, 3 reported a larger share at or above 4 pCi/L and 2 a smaller one; the spread is 43.3% (Hardin County) to 65.3% (Marion County). By share, Wyandot County is 54th of 79 Ohio counties with 30 or more tests for the same period.
Half the tests came in under 3.6 pCi/L and half over it; the single highest reached 66.6 pCi/L. Below the action level, 76 tests (23.8%) came in under 2 pCi/L, against 23.1% statewide, and 96 tests (30.0%) fell between 2 and 4, against 24.6% statewide.
Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 46.3% share point the same way here. USGS geology rates 100% of the county's land high radon potential. CDC also counts 5 tests taken after mitigation in Wyandot County for the same period: tests in homes where a fix was already in.
CDC's ten-year totals for Wyandot County went from 273 tests (2005 to 2014) to 320 (2008 to 2017), the share going from 43.6% to 46.3%.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Wyandot County, Geology
The ground under Wyandot County
PredictedUSGS's geologic map puts all of Wyandot 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.
Wyandot County beside the ground around it
Wyandot 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; Crawford County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Wyandot County, Local resources
Radon testing and mitigation in Wyandot County
Listed radon businesses with an address in Wyandot 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.
Listed radon professionals by town: Sycamore
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
Wyandot County, Questions
Questions about radon in Wyandot County
Are radon levels high in Wyandot County?
Over the 2008 to 2017 laboratory totals, 46.3% of the radon tests reported to CDC for Wyandot County, Ohio were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.6 pCi/L. Of 79 Ohio counties with 30 or more tests for the same period, 53 reported a higher share; pooled, the state comes to 52.3%.
Which counties border Wyandot County?
Wyandot County borders 5 counties: Seneca County, Crawford County, Marion County, Hardin County and Hancock County.
Products
Wyandot County, Products
Testing a home in Wyandot County
In Wyandot County, 46.3% of 320 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 Wyandot 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 USB-powered radon monitor with a color screen
- C-NRPP 2024/25: Not included
- Plug-in
- Alarm
- Screen
First reading: Within 5 minutes
Short-term kitKidde
442020 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 3 days
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Wyandot County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Wyandot County
Explore
Wyandot County, Bordering counties
Counties bordering Wyandot County
Calculated by Radon411- Radon levels in Marion CountyEPA zone 1
65.3%at or above 4 pCi/L
Median 6.4 pCi/L · 265 tests · 19.0 points above Wyandot County
- Radon levels in Crawford CountyEPA zone 1
59.5%at or above 4 pCi/L
Median 4.7 pCi/L · 210 tests · 13.2 points above Wyandot County
- Radon levels in Seneca CountyEPA zone 1
58.9%at or above 4 pCi/L
Median 4.9 pCi/L · 540 tests · 12.6 points above Wyandot County
- Radon levels in Hancock CountyEPA zone 1
46.2%at or above 4 pCi/L
Median 3.7 pCi/L · 1,382 tests · 0.1 points below Wyandot County
- Radon levels in Hardin CountyEPA zone 1
43.3%at or above 4 pCi/L
Median 3.4 pCi/L · 67 tests · 3.0 points below Wyandot County
Wyandot County, Cities and towns
Cities and towns in Wyandot County
About 21,567 people live in Wyandot County by the Census Bureau's estimate for July 1, 2025, 311 fewer than in 2020 (−1.4%). That works out to 53 people per square mile of land. Its largest town, Upper Sandusky, has 6,661 residents, 30.9% of the total. Together its 8 incorporated places hold 57.2% of those residents; the other 42.8% live outside any of them. Testing is reported here more often than across the state: CDC's 320 reported tests for 2008 to 2017 come to 14.8 for every 1,000 residents (2025 estimate), against 8.3 for Ohio.
From Upper Sandusky to Marseilles, CDC publishes no figure by town: each reads Wyandot County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Upper Sandusky | 6,661 | −0.6% | 30.9% |
| Carey | 3,529 | −0.9% | 16.4% |
| Sycamore | 771 | −2.8% | 3.6% |
| Nevada | 698 | −1.3% | 3.2% |
| Wharton | 320 | −2.7% | 1.5% |
| Harpster | 155 | −3.7% | 0.7% |
| Kirby | 116 | −2.5% | 0.5% |
| Marseilles | 95 | −2.1% | 0.4% |
8 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).
Wyandot County, Homes
Homes in Wyandot County
Wyandot County is a place of houses on their own lots: 80% of its 9,885 homes are detached single-family houses, against 69% across Ohio. The homes are older than Ohio's as a whole: half were built before 1962 (1970 for Ohio), and 48% date from before 1960. 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 | Wyandot County | Ohio |
|---|---|---|
| Housing units | 9,885 | 5,271,573 |
| Detached houses | 80% | 69% |
| In buildings of 5 or more | 6% | 15% |
| Mobile homes | 5% | 4% |
| Built before 1960 | 48% | 38% |
| Built since 2000 | 11% | 16% |
| Middle year built | 1962 | 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.