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Radon Levels in Stark County, Ohio

EPA puts Stark County in Zone 1, its highest radon zone, and high results are common there: 60.1% of the 3,317 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

    60.1%

    7.8 pts above OH

    Stark
    60.1%
    Ohio
    52.3%

    3,317 tests, 2008 to 2017

  • Median result

    4.9pCi/L

    Action level reached

    Stark
    4.9 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    3,317

    7th of 79 by tests

    Stark
    3,317
    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

    24 of 79

    Middle half

    Stark
    60.1%
    Pickaway
    81.4%

    By share, of 79 with 30+ tests

Read a result for Stark County

Starts at Stark County's median, 4.9 pCi/L

4.9pCi/L

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

EPA’s reading of 4.9 pCi/L

At or above 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 at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. Stark County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Stark County, At a glance

Stark County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Stark 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: Moderate across 56% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Stark County, 2008 to 2017, laboratory

Reported results by concentration band, Stark County, 2008 to 2017, laboratory
Under 2 pCi/L: 15%2 to 4 pCi/L: 25%4 pCi/L and above: 60%

Of 3,317 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Stark County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L49514.9%
2 to 4 pCi/L82825.0%
4 pCi/L and above1,99460.1%
What these figures count

These are the 3,317 tests reported to CDC for Stark 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

Stark County, Compared

Stark County radon figures, compared

Calculated by Radon411

More than half: 60.1% of the 3,317 radon tests reported to CDC for Stark County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 24th 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, 4.9 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 277.0 pCi/L. The rest split 14.9% under 2 pCi/L and 25.0% 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.

3 of its 8 bordering counties with figures ran higher, led by Tuscarawas County at 66.4%; Mahoning County reported 23.4%. 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 Stark County went from 2,141 tests (2005 to 2014) to 3,317 (2008 to 2017), the share going from 61.1% to 60.1%.

Nationally, every county with a figure for the same period pools to 35.7%; Stark County sits 24.4 points above it. CDC also counts 302 tests taken after mitigation in Stark County for the same period: tests in homes where a fix was already in.

Stark County against Ohio, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Stark County
Stark County3,31760.1%4.9 pCi/LThis county
Ohio, pooled88 counties, pooled98,84052.3%Not pooled−7.8 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−24.4 points
Pickaway Countyhighest in the state18381.4%9.5 pCi/L+21.3 points
Cuyahoga Countylowest in the state10,09221.7%2.0 pCi/L−38.4 points
Tuscarawas County, OHborders it54766.4%5.6 pCi/L+6.3 points
Holmes County, OHborders it6764.2%5.8 pCi/L+4.1 points
Wayne County, OHborders it1,07461.8%4.9 pCi/L+1.7 points
Carroll County, OHborders it48657.4%4.8 pCi/L−2.7 points
Columbiana County, OHborders it66249.1%3.8 pCi/L−11.0 points
Portage County, OHborders it1,66139.3%3.2 pCi/L−20.8 points
Summit County, OHborders it6,48638.7%3.1 pCi/L−21.4 points
Mahoning County, OHborders it66623.4%2.5 pCi/L−36.7 points
Where Stark County's reported results fell, 2008 to 2017, laboratory, beside Ohio and the United States
ResultStark County testsStark County shareOhio shareU.S. shareAgainst Ohio
Under 2 pCi/L49514.9%23.1%39.6%−8.2 points
2 to 4 pCi/L82825.0%24.6%24.7%+0.4 points
4 pCi/L and above1,99460.1%52.3%35.7%+7.8 points
Stark 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
Preble County19 of 7921262.7%5.5 pCi/L
Richland County20 of 791,32762.2%5.2 pCi/L
Wayne County21 of 791,07461.8%4.9 pCi/L
Henry County22 of 793461.8%5.3 pCi/L
Union County23 of 791,28560.2%4.8 pCi/L
Stark County24 of 793,31760.1%4.9 pCi/L
Shelby County25 of 7924860.1%5.2 pCi/L
Putnam County26 of 799459.6%4.8 pCi/L
Crawford County27 of 7921059.5%4.7 pCi/L
Huron County28 of 7979659.4%4.9 pCi/L
Sandusky County29 of 7964959.2%5.0 pCi/L
Stark County ten-year laboratory totals, against Ohio's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestOhio, pooledChange from the row before
2008 to 20173,31760.1%4.9 pCi/L277.0 pCi/L52.3%−0.8 points
2007 to 20162,92160.9%5.0 pCi/L277.0 pCi/L52.8%−0.6 points
2006 to 20152,47261.5%5.1 pCi/L322.9 pCi/L52.9%+0.4 points
2005 to 20142,14161.1%5.1 pCi/L322.9 pCi/L52.4%First on file

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

Stark County, Geology

The ground under Stark County

Predicted

USGS's geologic map splits Stark County: 56.2% of its land is moderate radon potential and 43.8% high. The map puts 56.2% of Stark County in the area it calls Glaciated Plateau and 43.8% in Area of Elevated Radioactivity. USGS gives the first a radon index of 11, in the moderate band (9 to 11), and the second 12, in the high band (12 to 17).

USGS's geologic areas under Stark County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Glaciated PlateauDevonian, Mississippian and Permian carbonates and shales.Moderate1156.2%
Area of Elevated RadioactivityPennsylvanian shale, sandstone, coal, and limestone.High1243.8%

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

Stark County beside the ground around it

Ohio as a whole has more high-potential ground than Stark County: 62.8% of its land, against 43.8% here. Of the 8 counties that border it, 5 have more high-potential ground, Holmes County the most at 100%.

Share of land by USGS radon potential: Stark County, the 8 counties bordering it and Ohio
AreaEPA zoneLow potentialModerate potentialHigh potential
Stark CountyZone 1None56.2%43.8%
Carroll CountyZone 1None11.8%88.2%
Summit CountyZone 1None100%None
Tuscarawas CountyZone 1NoneNone100%
Wayne CountyZone 1None34.6%65.4%
Columbiana CountyZone 1None39.2%60.8%
Portage CountyZone 2None100%None
Mahoning CountyZone 2None100%None
Holmes CountyZone 1NoneNone100%
Ohio88 counties, pooled by land areaVariesNone37.2%62.8%

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

Local help

Stark County, Local resources

Radon testing and mitigation in Stark County

Listed radon businesses with an address in Stark County:

Listed radon professionals by town: Canton, Massillon, Alliance, North Canton, Louisville, Canal Fulton, Hartville, East Canton

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

Stark County, Questions

Questions about radon in Stark County

Are radon levels high in Stark County?

Over the 2008 to 2017 laboratory totals, 60.1% of the radon tests reported to CDC for Stark County, Ohio were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.9 pCi/L. Of 79 Ohio counties with 30 or more tests for the same period, 23 reported a higher share; pooled, the state comes to 52.3%.

Which counties border Stark County?

Stark County borders 8 counties: Carroll County, Summit County, Tuscarawas County, Wayne County, Columbiana County, Portage County, Mahoning County and Holmes County.

Products

Stark County, Products

Testing a home in Stark County

In Stark County, 60.1% of 3,317 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 Stark 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

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

Explore

Stark County, Bordering counties

Counties bordering Stark County

Calculated by Radon411

Stark County, Cities and towns

Cities and towns in Stark County

Stark County's population has barely moved since 2020: 373,771 residents on July 1, 2025 against 374,476 then, by the Census Bureau's estimates. That works out to 650 people per square mile of land. No town dominates: Canton, the largest, has 69,001 residents, 18.5% of the total. CDC's 3,317 reported tests for 2008 to 2017 work out to 8.9 per 1,000 residents (2025 estimate), close to Ohio's 8.3.

From Canton to Hills and Dales, CDC publishes no figure by town: each reads Stark County's.

The 12 largest cities and towns in Stark County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Canton69,001−2.2%18.5%
Massillon32,168+0.5%8.6%
Allianceextends beyond Stark County21,582−0.2%Counted whole
North Canton17,692−0.8%4.7%
Louisville9,874+4.3%2.6%
Canal Fulton5,412+1.5%1.4%
Minervaextends beyond Stark County3,697+0.2%Counted whole
Hartville3,456+3.6%0.9%
Brewster2,192+0.6%0.6%
Navarre1,805−2.7%0.5%
East Canton1,513Level0.4%
Magnoliaextends beyond Stark County1,013−0.2%Counted whole
  • Beach City
  • Waynesburg
  • East Sparta
  • Meyers Lake
  • Wilmot
  • Hills and Dales

18 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 Stark County is counted whole, so it has no share.

Stark County, Homes

Homes in Stark County

Stark County is a place of houses on their own lots: 75% of its 167,525 homes are detached single-family houses, against 69% across Ohio. Half of its homes were built before 1966, close to Ohio's 1970: 43% date from before 1960 and 11% 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 Stark County, Ohio, 2019 to 2023
HomesStark CountyOhio
Housing units167,5255,271,573
Detached houses75%69%
In buildings of 5 or more10%15%
Mobile homes2%4%
Built before 196043%38%
Built since 200011%16%
Middle year built19661970
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.