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Radon Levels in Mahoning County, Ohio

EPA puts Mahoning County in Zone 2, its middle radon zone, and 23.4% of its 666 reported radon tests (2008 to 2017, laboratory totals) were 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

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  • Share at 4+ pCi/L

    23.4%

    28.9 pts below OH

    Mahoning
    23.4%
    Ohio
    52.3%

    666 tests, 2008 to 2017

  • Median result

    2.5pCi/L

    Below action level

    Mahoning
    2.5 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    666

    32nd of 79 by tests

    Mahoning
    666
    Franklin
    16,142

    Reported to CDC before any fix, 2008 to 2017

  • EPA radon zone

    Zone 2

    Moderate potential

    1. 1
    2. Zone 2
    3. 3

    1 highest, 3 lowest

    EPA predicts 2 to 4 pCi/L indoors

  • Rank in Ohio

    77 of 79

    Lowest quarter

    Mahoning
    23.4%
    Pickaway
    81.4%

    By share, of 79 with 30+ tests

Read a result for Mahoning County

Starts at Mahoning County's median, 2.5 pCi/L

2.5pCi/L

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

EPA’s reading of 2.5 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. Mahoning County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Mahoning County, At a glance

Mahoning County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Mahoning County is a county: EPA's forecast for it as a whole is an average indoor of 2 to 4 pCi/L (75 to 150 Bq/m³). It describes no single address, and homes above EPA's are found in every zone, this one included.

USGS geologic potential: Moderate across 100% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

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

Reported results by concentration band, Mahoning County, 2008 to 2017, laboratory
Under 2 pCi/L: 36%2 to 4 pCi/L: 41%4 pCi/L and above: 23%

Of 666 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Mahoning County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L23835.7%
2 to 4 pCi/L27240.8%
4 pCi/L and above15623.4%
What these figures count

These are the 666 tests reported to CDC for Mahoning 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

Mahoning County, Compared

Mahoning County radon figures, compared

Calculated by Radon411

Mahoning County's 666 reported tests over the 2008 to 2017 laboratory totals had a middle value of 2.5 pCi/L and a maximum of 44.1 pCi/L, and 23.4% reached 4 pCi/L. Ohio as a whole (88 Ohio counties, pooled) comes to 52.3%: 28.9 points higher than here.

Among its state's counties it ranks 77th of 79 Ohio counties with 30 or more tests for the same period. Statewide for the same period, Pickaway County reported the highest share (81.4%) and Cuyahoga County the lowest (21.7%).

Below the action level, 238 tests (35.7%) came in under 2 pCi/L, against 23.1% statewide, and 272 tests (40.8%) fell between 2 and 4, against 24.6% statewide. CDC's ten-year totals for Mahoning County went from 761 tests (2005 to 2014) to 666 (2008 to 2017), the share going from 20.9% to 23.4%.

EPA's 1993 zone map puts Mahoning County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 100% of the county's land moderate radon potential.

Next door, the shares run from 34.6% in Trumbull County to 60.1% in Stark County.

CDC also counts 21 tests taken after mitigation in Mahoning County for the same period: tests in homes where a fix was already in.

Mahoning County against Ohio, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Mahoning County
Mahoning County66623.4%2.5 pCi/LThis county
Ohio, pooled88 counties, pooled98,84052.3%Not pooled+28.9 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+12.3 points
Pickaway Countyhighest in the state18381.4%9.5 pCi/L+58.0 points
Cuyahoga Countylowest in the state10,09221.7%2.0 pCi/L−1.7 points
Stark County, OHborders it3,31760.1%4.9 pCi/L+36.7 points
Columbiana County, OHborders it66249.1%3.8 pCi/L+25.7 points
Lawrence County, PAborders it1,19142.9%3.3 pCi/L+19.5 points
Portage County, OHborders it1,66139.3%3.2 pCi/L+15.9 points
Mercer County, PAborders it1,40836.7%3.0 pCi/L+13.3 points
Trumbull County, OHborders it42534.6%2.9 pCi/L+11.2 points
Where Mahoning County's reported results fell, 2008 to 2017, laboratory, beside Ohio and the United States
ResultMahoning County testsMahoning County shareOhio shareU.S. shareAgainst Ohio
Under 2 pCi/L23835.7%23.1%39.6%+12.6 points
2 to 4 pCi/L27240.8%24.6%24.7%+16.2 points
4 pCi/L and above15623.4%52.3%35.7%−28.9 points
Mahoning 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
Athens County69 of 7931838.1%3.1 pCi/L
Scioto County70 of 797337.0%2.7 pCi/L
Hamilton County71 of 793,75434.7%2.8 pCi/L
Trumbull County72 of 7942534.6%2.9 pCi/L
Ashtabula County73 of 7931434.4%2.5 pCi/L
Noble County74 of 794231.0%2.2 pCi/L
Lawrence County75 of 796630.3%2.5 pCi/L
Lake County76 of 792,34927.2%2.4 pCi/L
Mahoning County77 of 7966623.4%2.5 pCi/L
Geauga County78 of 791,46923.4%2.4 pCi/L
Cuyahoga County79 of 7910,09221.7%2.0 pCi/L
Mahoning County ten-year laboratory totals, against Ohio's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestOhio, pooledChange from the row before
2008 to 201766623.4%2.5 pCi/L44.1 pCi/L52.3%+2.1 points
2007 to 201680021.3%2.2 pCi/L44.1 pCi/L52.8%+0.2 points
2006 to 201586421.1%2.2 pCi/L44.1 pCi/L52.9%+0.2 points
2005 to 201476120.9%2.3 pCi/L36.4 pCi/L52.4%First on file

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

Mahoning County, Geology

The ground under Mahoning County

Predicted

USGS's geologic map puts all of Mahoning County's mapped land in one class: moderate radon potential. All of it lies in the area the map calls Glaciated Plateau, to which USGS gives a radon index of 11, in the moderate band (9 to 11).

USGS's geologic areas under Mahoning County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Glaciated PlateauDevonian, Mississippian and Permian carbonates and shales.Moderate11100%

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

Mahoning County beside the ground around it

Across Ohio 62.8% of the land is rated high; none of Mahoning County's is. Of the 6 counties that border it, 4 have more high-potential ground, Columbiana County the most at 60.8%.

Share of land by USGS radon potential: Mahoning County, the 6 counties bordering it and Ohio
AreaEPA zoneLow potentialModerate potentialHigh potential
Mahoning CountyZone 2None100%None
Trumbull CountyZone 2None100%None
Columbiana CountyZone 1None39.2%60.8%
Lawrence County, PAZone 2None80.7%19.3%
Portage CountyZone 2None100%None
Mercer County, PAZone 2None99.1%0.9%
Stark CountyZone 1None56.2%43.8%
Ohio88 counties, pooled by land areaVariesNone37.2%62.8%

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

Local help

Mahoning County, Local resources

Radon testing and mitigation in Mahoning County

Listed radon businesses with an address in Mahoning County:

Listed radon professionals by town: Youngstown, Alliance, Salem, Lowellville

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

Mahoning County, Questions

Questions about radon in Mahoning County

Are radon levels high in Mahoning County?

Over the 2008 to 2017 laboratory totals, 23.4% of the radon tests reported to CDC for Mahoning County, Ohio were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.5 pCi/L. Of 79 Ohio counties with 30 or more tests for the same period, 76 reported a higher share; pooled, the state comes to 52.3%.

Which counties border Mahoning County?

Mahoning County borders 6 counties: Trumbull County, OH, Columbiana County, OH, Lawrence County, PA, Portage County, OH, Mercer County, PA and Stark County, OH.

Products

Mahoning County, Products

Testing a home in Mahoning County

In Mahoning County, 23.4% of 666 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 52.3% pooled across Ohio. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Mahoning County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Mahoning County homes, compared

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Mahoning County, Bordering counties

Counties bordering Mahoning County

Calculated by Radon411

Mahoning County, Cities and towns

Cities and towns in Mahoning County

About 224,706 people live in Mahoning County by the Census Bureau's estimate for July 1, 2025, 3,300 fewer than in 2020 (−1.4%). That works out to 546 people per square mile of land. Youngstown, the largest place on its list (58,832 residents in all), extends beyond Mahoning County, so no share of the total is worked out for it. Reported testing is thin here: 666 tests over 2008 to 2017, or 3.0 for every 1,000 residents (2025 estimate), where Ohio as a whole comes to 8.3.

From Youngstown to Washingtonville, CDC publishes no figure by town: each reads Mahoning County's.

The 12 largest cities and towns in Mahoning County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Youngstownextends beyond Mahoning County58,832−1.8%Counted whole
Allianceextends beyond Mahoning County21,582−0.2%Counted whole
Salemextends beyond Mahoning County11,655−2.0%Counted whole
Struthers9,837−1.7%4.4%
Campbell7,721−1.6%3.4%
Canfield7,584−1.2%3.4%
Columbianaextends beyond Mahoning County6,756+2.8%Counted whole
Sebring4,065−2.6%1.8%
Poland2,418−1.5%1.1%
New Middletown1,486−1.2%0.7%
Craig Beach1,004−1.3%0.4%
Lowellville976−1.8%0.4%
  • Beloit
  • Washingtonville (part)

14 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 Mahoning County is counted whole, so it has no share.

Mahoning County, Homes

Homes in Mahoning County

Mahoning County is a place of houses on their own lots: 78% of its 108,077 homes are detached single-family houses, against 69% across Ohio. Half of its homes were built before 1963, close to Ohio's 1970: 46% date from before 1960 and 9% from 2000 or later. 70% 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 Mahoning County, Ohio, 2019 to 2023
HomesMahoning CountyOhio
Housing units108,0775,271,573
Detached houses78%69%
In buildings of 5 or more11%15%
Mobile homes2%4%
Built before 196046%38%
Built since 20009%16%
Middle year built19631970
Owner-occupied70%67%

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