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Radon Levels in Hancock County, Ohio

EPA puts Hancock County in Zone 1, its highest radon zone, and high results are common there: 46.2% of the 1,382 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

How to test this homeFind a certified tester

  • Share at 4+ pCi/L

    46.2%

    6.1 pts below OH

    Hancock
    46.2%
    Ohio
    52.3%

    1,382 tests, 2008 to 2017

  • Median result

    3.7pCi/L

    Below action level

    Hancock
    3.7 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    1,382

    20th of 79 by tests

    Hancock
    1,382
    Franklin
    16,142

    Reported to CDC before any fix, 2008 to 2017

  • EPA radon zone

    Zone 1

    Highest potential

    1. Zone 1
    2. 2
    3. 3

    1 highest, 3 lowest

    EPA predicts over 4 pCi/L indoors

  • Rank in Ohio

    55 of 79

    Middle half

    Hancock
    46.2%
    Pickaway
    81.4%

    By share, of 79 with 30+ tests

Read a result for Hancock County

Starts at Hancock County's median, 3.7 pCi/L

3.7pCi/L

EPA’s own thresholds; the figures are the area’s, never this home’s.

EPA’s reading of 3.7 pCi/L

Between 2 and 4 pCi/L

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 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. Hancock County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Hancock County, At a glance

Hancock County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Hancock County in and predicts an average indoor of greater than 4 pCi/L (greater than 150 Bq/m³) across the county. That is one forecast for the whole county, not a reading of any address in it; homes above EPA's turn up in all three zones.

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 Hancock County, 2008 to 2017, laboratory

Reported results by concentration band, Hancock County, 2008 to 2017, laboratory
Under 2 pCi/L: 26%2 to 4 pCi/L: 28%4 pCi/L and above: 46%

Of 1,382 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Hancock County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L35225.5%
2 to 4 pCi/L39128.3%
4 pCi/L and above63946.2%
What these figures count

These are the 1,382 tests reported to CDC for Hancock 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).

How to read these figures

Hancock County, Compared

Hancock County radon figures, compared

Calculated by Radon411

In Hancock County, about 5 in 10 reported tests over the 2008 to 2017 laboratory totals (639 of 1,382) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 10.5 points higher. Across 88 Ohio counties pooled together, 52.3% of tests reached that level, so Hancock County runs 6.1 points below its state.

Of 7 neighbours with a figure, 5 reported a larger share at or above 4 pCi/L and 2 a smaller one; the spread is 43.3% (Hardin County) to 61.8% (Henry County). By share, Hancock County is 55th of 79 Ohio counties with 30 or more tests for the same period.

Half the tests came in under 3.7 pCi/L and half over it; the single highest reached 75.8 pCi/L. Below the action level, 352 tests (25.5%) came in under 2 pCi/L, against 23.1% statewide, and 391 tests (28.3%) fell between 2 and 4, against 24.6% statewide.

Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 46.2% share point the same way here. USGS geology rates 100% of the county's land high radon potential. CDC also counts 45 tests taken after mitigation in Hancock County for the same period: tests in homes where a fix was already in.

CDC's ten-year totals for Hancock County went from 1,069 tests (2005 to 2014) to 1,382 (2008 to 2017), the share going from 45.0% to 46.2%.

Hancock County against Ohio, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Hancock County
Hancock County1,38246.2%3.7 pCi/LThis county
Ohio, pooled88 counties, pooled98,84052.3%Not pooled+6.1 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−10.5 points
Pickaway Countyhighest in the state18381.4%9.5 pCi/L+35.2 points
Cuyahoga Countylowest in the state10,09221.7%2.0 pCi/L−24.5 points
Henry County, OHborders it3461.8%5.3 pCi/L+15.6 points
Putnam County, OHborders it9459.6%4.8 pCi/L+13.4 points
Seneca County, OHborders it54058.9%4.9 pCi/L+12.7 points
Allen County, OHborders it23856.7%5.0 pCi/L+10.5 points
Wyandot County, OHborders it32046.3%3.6 pCi/L+0.1 points
Wood County, OHborders it1,19245.5%3.5 pCi/L−0.7 points
Hardin County, OHborders it6743.3%3.4 pCi/L−2.9 points
Where Hancock County's reported results fell, 2008 to 2017, laboratory, beside Ohio and the United States
ResultHancock County testsHancock County shareOhio shareU.S. shareAgainst Ohio
Under 2 pCi/L35225.5%23.1%39.6%+2.4 points
2 to 4 pCi/L39128.3%24.6%24.7%+3.7 points
4 pCi/L and above63946.2%52.3%35.7%−6.1 points
Hancock County ranked among the 79 Ohio counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Columbiana County50 of 7966249.1%3.8 pCi/L
Perry County51 of 799048.9%3.8 pCi/L
Defiance County52 of 797048.6%3.8 pCi/L
Brown County53 of 797047.1%3.3 pCi/L
Wyandot County54 of 7932046.3%3.6 pCi/L
Hancock County55 of 791,38246.2%3.7 pCi/L
Wood County56 of 791,19245.5%3.5 pCi/L
Lorain County57 of 793,30745.4%3.6 pCi/L
Belmont County58 of 7969745.2%3.6 pCi/L
Fulton County59 of 796245.2%3.1 pCi/L
Guernsey County60 of 7911744.4%3.6 pCi/L
Hancock County ten-year laboratory totals, against Ohio's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestOhio, pooledChange from the row before
2008 to 20171,38246.2%3.7 pCi/L75.8 pCi/L52.3%+0.6 points
2007 to 20161,27445.6%3.6 pCi/L75.8 pCi/L52.8%−0.3 points
2006 to 20151,18045.9%3.6 pCi/L86.2 pCi/L52.9%+0.9 points
2005 to 20141,06945.0%3.5 pCi/L86.2 pCi/L52.4%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period.

Hancock County, Geology

The ground under Hancock County

Predicted

USGS's geologic map puts all of Hancock 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).

USGS's geologic areas under Hancock County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Till PlainsGlacial deposits underlain by Ordovician through Devonian limestone and shale.High14100%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

Hancock County beside the ground around it

Hancock County has more high-potential ground than Ohio as a whole: 100% of its land against 62.8%. Of the 7 counties that border it, none has as large a share of high-potential ground; Allen County comes nearest at 100%.

Share of land by USGS radon potential: Hancock County, the 7 counties bordering it and Ohio
AreaEPA zoneLow potentialModerate potentialHigh potential
Hancock CountyZone 1NoneNone100%
Wood CountyZone 2None8.3%91.7%
Wyandot CountyZone 1NoneNone100%
Putnam CountyZone 2None32.3%67.7%
Henry CountyZone 2None25.7%74.3%
Seneca CountyZone 1None0.6%99.4%
Hardin CountyZone 1NoneNone100%
Allen CountyZone 1NoneNone100%
Ohio88 counties, pooled by land areaVariesNone37.2%62.8%

The map rates the ground, not the air in any home.

Local help

Hancock County, Local resources

Radon testing and mitigation in Hancock County

Listed radon businesses with an address in Hancock County:

Listed radon professionals by town: Findlay, Fostoria, Bluffton, Van Buren

What Ohio's program says
Phone
614-728-0272
Email
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

Hancock County, Questions

Questions about radon in Hancock County

Are radon levels high in Hancock County?

Over the 2008 to 2017 laboratory totals, 46.2% of the radon tests reported to CDC for Hancock County, Ohio were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.7 pCi/L. Of 79 Ohio counties with 30 or more tests for the same period, 54 reported a higher share; pooled, the state comes to 52.3%.

Which counties border Hancock County?

Hancock County borders 7 counties: Wood County, Wyandot County, Putnam County, Henry County, Seneca County, Hardin County and Allen County.

Products

Hancock County, Products

Testing a home in Hancock County

In Hancock County, 46.2% of 1,382 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 Hancock 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

Hancock County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Hancock County

Explore

Hancock County, Bordering counties

Counties bordering Hancock County

Calculated by Radon411

Hancock County, Cities and towns

Cities and towns in Hancock County

Hancock County's population has barely moved since 2020: 75,034 residents on July 1, 2025 against 74,939 then, by the Census Bureau's estimates. That works out to 141 people per square mile of land. Findlay alone is home to 40,370 of them, 53.8% of the total. Testing is reported here more often than across the state: CDC's 1,382 reported tests for 2008 to 2017 come to 18.4 for every 1,000 residents (2025 estimate), against 8.3 for Ohio.

From Findlay to Mount Cory, CDC publishes no figure by town: each reads Hancock County's.

The 12 largest cities and towns in Hancock County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Findlay40,370+0.2%53.8%
Fostoriaextends beyond Hancock County12,920−1.0%Counted whole
Blufftonextends beyond Hancock County3,875−2.2%Counted whole
McComb1,549−1.0%2.1%
Arlington1,457−2.0%1.9%
Arcadia553−1.8%0.7%
Rawson553−2.8%0.7%
Mount Blanchard457−2.4%0.6%
Van Buren399+0.8%0.5%
Vanlue339−2.0%0.5%
Benton Ridge265−2.9%0.4%
Jenera241−4.0%0.3%
  • Mount Cory

13 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. “(part)” marks a place that extends into another county. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025). A place that extends beyond Hancock County is counted whole, so it has no share.

Hancock County, Homes

Homes in Hancock County

Of Hancock County's 33,871 homes, 71% are detached houses, against 69% across Ohio; 12% are in buildings of five or more homes. Half of its homes were built before 1972, close to Ohio's 1970: 38% date from before 1960 and 17% from 2000 or later. 69% 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 in Hancock County, Ohio, 2019 to 2023
HomesHancock CountyOhio
Housing units33,8715,271,573
Detached houses71%69%
In buildings of 5 or more12%15%
Mobile homes6%4%
Built before 196038%38%
Built since 200017%16%
Middle year built19721970
Owner-occupied69%67%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.