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Radon Levels in Monroe County, Ohio

EPA puts Monroe County in Zone 2, its middle radon zone, and high results are common there: 58.3% of the 48 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

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  • Share at 4+ pCi/L

    58.3%

    6.0 pts above OH

    Monroe
    58.3%
    Ohio
    52.3%

    48 tests, 2008 to 2017

  • Median result

    5.0pCi/L

    Action level reached

    Monroe
    5.0 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    48

    75th of 79 by tests

    Monroe
    48
    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

    33 of 79

    Middle half

    Monroe
    58.3%
    Pickaway
    81.4%

    By share, of 79 with 30+ tests

Read a result for Monroe County

Starts at Monroe County's median, 5.0 pCi/L

5.0pCi/L

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

EPA’s reading of 5.0 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. Monroe County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Monroe County, At a glance

Monroe County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Monroe 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 Monroe County, 2008 to 2017, laboratory

Reported results by concentration band, Monroe County, 2008 to 2017, laboratory
Under 2 pCi/L: 15%2 to 4 pCi/L: 27%4 pCi/L and above: 58%

Of 48 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Monroe County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L714.6%
2 to 4 pCi/L1327.1%
4 pCi/L and above2858.3%
What these figures count

These are the 48 tests reported to CDC for Monroe 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

Monroe County, Compared

Monroe County radon figures, compared

Calculated by Radon411

More than half: 58.3% of the 48 radon tests reported to CDC for Monroe County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 33rd of 79 Ohio counties with 30 or more tests for the same period. That is 6.0 points above the 52.3% pooled from 88 Ohio counties.

The median result, 5.0 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 36.4 pCi/L. The rest split 14.6% under 2 pCi/L and 27.1% from 2 to 4 (Ohio: 23.1% and 24.6%). The reported tests do not follow EPA's Zone 2 label for Monroe County (predicted average between 2 and 4 pCi/L): 58.3% of them reached 4 pCi/L, fewer than that label suggests.

No bordering county with a figure for the same period reported a higher share; the closest is Belmont County at 45.2%, the lowest Tyler County, WV at 22.9%. 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 Monroe County went from 42 tests (2005 to 2014) to 48 (2008 to 2017), the share going from 61.9% to 58.3%.

Nationally, every county with a figure for the same period pools to 35.7%; Monroe County sits 22.6 points above it. CDC also counts 7 tests taken after mitigation in Monroe County for the same period: tests in homes where a fix was already in.

Monroe County against Ohio, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Monroe County
Monroe County4858.3%5.0 pCi/LThis county
Ohio, pooled88 counties, pooled98,84052.3%Not pooled−6.0 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−22.6 points
Pickaway Countyhighest in the state18381.4%9.5 pCi/L+23.1 points
Cuyahoga Countylowest in the state10,09221.7%2.0 pCi/L−36.6 points
Belmont County, OHborders it69745.2%3.6 pCi/L−13.1 points
Washington County, OHborders it34938.1%3.1 pCi/L−20.2 points
Wetzel County, WVborders it5435.2%2.7 pCi/L−23.1 points
Marshall County, WVborders it25431.9%2.5 pCi/L−26.4 points
Noble County, OHborders it4231.0%2.2 pCi/L−27.3 points
Tyler County, WVborders it3522.9%1.8 pCi/L−35.4 points
Where Monroe County's reported results fell, 2008 to 2017, laboratory, beside Ohio and the United States
ResultMonroe County testsMonroe County shareOhio shareU.S. shareAgainst Ohio
Under 2 pCi/L714.6%23.1%39.6%−8.5 points
2 to 4 pCi/L1327.1%24.6%24.7%+2.5 points
4 pCi/L and above2858.3%52.3%35.7%+6.0 points
Monroe 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
Huron County28 of 7979659.4%4.9 pCi/L
Sandusky County29 of 7964959.2%5.0 pCi/L
Coshocton County30 of 7911258.9%5.1 pCi/L
Seneca County31 of 7954058.9%4.9 pCi/L
Greene County32 of 792,60258.6%4.9 pCi/L
Monroe County33 of 794858.3%5.0 pCi/L
Mercer County34 of 7914957.7%5.1 pCi/L
Clark County35 of 791,44757.5%4.9 pCi/L
Carroll County36 of 7948657.4%4.8 pCi/L
Allen County37 of 7923856.7%5.0 pCi/L
Highland County38 of 796756.7%4.8 pCi/L
Monroe County ten-year laboratory totals, against Ohio's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestOhio, pooledChange from the row before
2008 to 20174858.3%5.0 pCi/L36.4 pCi/L52.3%−3.4 points
2007 to 20164761.7%5.0 pCi/L36.4 pCi/L52.8%+0.3 points
2006 to 20154461.4%5.2 pCi/L36.4 pCi/L52.9%−0.5 points
2005 to 20144261.9%5.2 pCi/L36.4 pCi/L52.4%First on file

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

Monroe County, Geology

The ground under Monroe County

Predicted

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

USGS's geologic areas under Monroe County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Unglaciated PlateauMississippian through Permian limestone, dolomite, and shale.Moderate11100%

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

Monroe County beside the ground around it

Across Ohio 62.8% of the land is rated high; none of Monroe County's is. Of the 6 counties that border it, 2 have more high-potential ground, Belmont County the most at 69.1%.

Share of land by USGS radon potential: Monroe County, the 6 counties bordering it and Ohio
AreaEPA zoneLow potentialModerate potentialHigh potential
Monroe CountyZone 2None100%None
Belmont CountyZone 1None30.9%69.1%
Tyler County, WVZone 2None100%None
Wetzel County, WVZone 1None100%None
Noble CountyZone 2None100%None
Marshall County, WVZone 1None96.8%3.2%
Washington CountyZone 2None100%None
Ohio88 counties, pooled by land areaVariesNone37.2%62.8%

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

Local help

Monroe County, Local resources

Radon testing and mitigation in Monroe County

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

Monroe County, Questions

Questions about radon in Monroe County

Are radon levels high in Monroe County?

Over the 2008 to 2017 laboratory totals, 58.3% of the radon tests reported to CDC for Monroe County, Ohio were at or above 4 pCi/L, and the median reported pre-mitigation result was 5.0 pCi/L. Of 79 Ohio counties with 30 or more tests for the same period, 32 reported a higher share; pooled, the state comes to 52.3%.

Which counties border Monroe County?

Monroe County borders 6 counties: Belmont County, OH, Tyler County, WV, Wetzel County, WV, Noble County, OH, Marshall County, WV and Washington County, OH.

Products

Monroe County, Products

Testing a home in Monroe County

In Monroe County, 58.3% of 48 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 Monroe County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Monroe County homes, compared

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Monroe County, Bordering counties

Counties bordering Monroe County

Calculated by Radon411

Monroe County, Cities and towns

Cities and towns in Monroe County

About 12,994 people live in Monroe County by the Census Bureau's estimate for July 1, 2025, 356 fewer than in 2020 (−2.7%). That works out to 29 people per square mile of land. No town dominates: Woodsfield, the largest, has 2,127 residents, 16.4% of the total. Reported testing is thin here: 48 tests over 2008 to 2017, or 3.7 for every 1,000 residents (2025 estimate), where Ohio as a whole comes to 8.3.

From Woodsfield to Miltonsburg, CDC publishes no figure by town: each reads Monroe County's.

The cities and towns in Monroe County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Woodsfield2,127−3.1%16.4%
Beallsville357−2.7%2.7%
Clarington271−2.5%2.1%
Lewisville177−3.8%1.4%
Jerusalem130−2.3%1.0%
Wilsonextends beyond Monroe County129−4.4%Counted whole
Antioch67−5.6%0.5%
Graysville66−2.9%0.5%
Stafford65−3.0%0.5%
Miltonsburg31−3.1%0.2%

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 Monroe County is counted whole, so it has no share.

Monroe County, Homes

Homes in Monroe County

Monroe County is a place of houses on their own lots: 76% of its 7,147 homes are detached single-family houses, against 69% across Ohio. Half of its homes were built before 1974, close to Ohio's 1970: 34% date from before 1960 and 21% from 2000 or later. Owners live in 82% of the occupied homes (Ohio: 67%), so for most households a test and a fix are their own to order.

Homes in Monroe County, Ohio, 2019 to 2023
HomesMonroe CountyOhio
Housing units7,1475,271,573
Detached houses76%69%
In buildings of 5 or more3%15%
Mobile homes19%4%
Built before 196034%38%
Built since 200021%16%
Middle year built19741970
Owner-occupied82%67%

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