Skip to content
RADON411

Locations and reports

Radon Levels in Mitchell County, Iowa

EPA puts Mitchell County in Zone 1, its highest radon zone, and high results are common there: 70.7% of the 444 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

    70.7%

    12.2 pts above IA

    Mitchell
    70.7%
    Iowa
    58.5%

    444 tests, 2008 to 2017

  • Median result

    6.4pCi/L

    Action level reached

    Mitchell
    6.4 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    444

    53rd of 99 by tests

    Mitchell
    444
    Polk
    10,945

    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 Iowa

    26 of 99

    Middle half

    Mitchell
    70.7%
    Sioux
    84.2%

    By share, of 99 with 30+ tests

Read a result for Mitchell County

Starts at Mitchell County's median, 6.4 pCi/L

6.4pCi/L

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

EPA’s reading of 6.4 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. Mitchell County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Mitchell County, At a glance

Mitchell County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Mitchell 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 Mitchell County, 2008 to 2017, laboratory

Reported results by concentration band, Mitchell County, 2008 to 2017, laboratory
Under 2 pCi/L: 14%2 to 4 pCi/L: 15%4 pCi/L and above: 71%

Of 444 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Mitchell County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L6314.2%
2 to 4 pCi/L6715.1%
4 pCi/L and above31470.7%
What these figures count

These are the 444 tests reported to CDC for Mitchell 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

Mitchell County, Compared

Mitchell County radon figures, compared

Calculated by Radon411

More than half: 70.7% of the 444 radon tests reported to CDC for Mitchell County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 26th of 99 Iowa counties with 30 or more tests for the same period. That is 12.2 points above the 58.5% pooled from 99 Iowa counties.

The median result, 6.4 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 103.0 pCi/L. The rest split 14.2% under 2 pCi/L and 15.1% from 2 to 4 (Iowa: 21.8% and 19.7%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 70.7% share point the same way here.

No bordering county with a figure for the same period reported a higher share; the closest is Worth County at 67.5%, the lowest Mower County, MN at 48.2%. Statewide for the same period, Sioux County reported the highest share (84.2%) and Decatur County the lowest (25.9%).

CDC's ten-year totals for Mitchell County went from 391 tests (2005 to 2014) to 444 (2008 to 2017), the share going from 70.1% to 70.7%.

Nationally, every county with a figure for the same period pools to 35.7%; Mitchell County sits 35.0 points above it. CDC also counts 56 tests taken after mitigation in Mitchell County for the same period: tests in homes where a fix was already in.

Mitchell County against Iowa, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Mitchell County
Mitchell County44470.7%6.4 pCi/LThis county
Iowa, pooled99 counties, pooled95,24558.5%Not pooled−12.2 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−35.0 points
Sioux Countyhighest in the state1,98284.2%10.7 pCi/L+13.5 points
Decatur Countylowest in the state8525.9%2.5 pCi/L−44.8 points
Worth County, IAborders it15467.5%6.0 pCi/L−3.2 points
Howard County, IAborders it38861.3%5.9 pCi/L−9.4 points
Floyd County, IAborders it69759.5%5.1 pCi/L−11.2 points
Cerro Gordo County, IAborders it1,66259.0%4.8 pCi/L−11.7 points
Chickasaw County, IAborders it49859.0%4.9 pCi/L−11.7 points
Mower County, MNborders it50048.2%3.8 pCi/L−22.5 points
Where Mitchell County's reported results fell, 2008 to 2017, laboratory, beside Iowa and the United States
ResultMitchell County testsMitchell County shareIowa shareU.S. shareAgainst Iowa
Under 2 pCi/L6314.2%21.8%39.6%−7.6 points
2 to 4 pCi/L6715.1%19.7%24.7%−4.6 points
4 pCi/L and above31470.7%58.5%35.7%+12.2 points
Mitchell County ranked among the 99 Iowa counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Page County21 of 9965371.7%7.2 pCi/L
Greene County22 of 9914371.3%6.2 pCi/L
Emmet County23 of 9942071.0%6.3 pCi/L
Guthrie County24 of 9925770.8%6.9 pCi/L
Palo Alto County25 of 9946270.8%5.9 pCi/L
Mitchell County26 of 9944470.7%6.4 pCi/L
Poweshiek County27 of 9941970.6%7.2 pCi/L
Dickinson County28 of 9983170.3%7.0 pCi/L
Marshall County29 of 9957070.2%8.2 pCi/L
Humboldt County30 of 9938570.1%7.0 pCi/L
Mills County31 of 9946570.1%6.1 pCi/L
Mitchell County ten-year laboratory totals, against Iowa's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestIowa, pooledChange from the row before
2008 to 201744470.7%6.4 pCi/L103.0 pCi/L58.5%−1.0 points
2007 to 201643571.7%6.5 pCi/L103.0 pCi/L58.6%+0.5 points
2006 to 201541671.2%6.5 pCi/L103.0 pCi/L59.4%+1.1 points
2005 to 201439170.1%6.4 pCi/L103.0 pCi/L59.6%First on file

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

Mitchell County, Geology

The ground under Mitchell County

Predicted

USGS's geologic map puts all of Mitchell County's mapped land in one class: high radon potential. All of it lies in the area the map calls Iowan Surface, to which USGS gives a radon index of 12, in the high band (12 to 17).

USGS's geologic areas under Mitchell County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Iowan SurfacePre-Illinoian glaical deposits and loess.High12100%

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

Mitchell County beside the ground around it

On high-potential ground Mitchell County is close to Iowa as a whole: 100% of its land against 98.8%. Of the 6 counties that border it, none has as large a share of high-potential ground; Cerro Gordo County comes nearest at 100%.

Share of land by USGS radon potential: Mitchell County, the 6 counties bordering it and Iowa
AreaEPA zoneLow potentialModerate potentialHigh potential
Mitchell CountyZone 1NoneNone100%
Mower County, MNZone 1NoneNone100%
Floyd CountyZone 1NoneNone100%
Worth CountyZone 1NoneNone100%
Howard CountyZone 1NoneNone100%
Cerro Gordo CountyZone 1NoneNone100%
Chickasaw CountyZone 1NoneNone100%
Iowa99 counties, pooled by land areaVariesNone1.2%98.8%

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

Local help

Mitchell County, Local resources

Radon testing and mitigation in Mitchell County

What Iowa's program says
Phone
(515) 281-4928
Licensing of radon professionals
Iowa’s radon program approves applications for persons who wish to become certified to perform radon testing or credentialed to perform mitigation and laboratories that provide radon testing devices and analytical services.
Disclosure when a home is sold or rented
However, per Iowa Code chapters 543B.9 and 543B.18 and Iowa Administrative Code 193E Chapter 14 administered by the Iowa Real Estate Commission, a seller must disclose any known tests for the presence of radon and if yes, provide the date of last report and the result(s).

What it means

Mitchell County, Questions

Questions about radon in Mitchell County

Are radon levels high in Mitchell County?

Over the 2008 to 2017 laboratory totals, 70.7% of the radon tests reported to CDC for Mitchell County, Iowa were at or above 4 pCi/L, and the median reported pre-mitigation result was 6.4 pCi/L. Of 99 Iowa counties with 30 or more tests for the same period, 25 reported a higher share; pooled, the state comes to 58.5%.

Which counties border Mitchell County?

Mitchell County borders 6 counties: Mower County, MN, Floyd County, IA, Worth County, IA, Howard County, IA, Cerro Gordo County, IA and Chickasaw County, IA.

Products

Mitchell County, Products

Testing a home in Mitchell County

In Mitchell County, 70.7% of 444 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 58.5% pooled across Iowa. In Zone 1 the year-round level in Mitchell 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

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

Explore

Mitchell County, Bordering counties

Counties bordering Mitchell County

Calculated by Radon411

Mitchell County, Cities and towns

Cities and towns in Mitchell County

The Census Bureau estimates 10,650 residents in Mitchell County for July 1, 2025, 59 more than in 2020 (+0.6%). That works out to 23 people per square mile of land. Its largest town, Osage, has 3,552 residents, 33.4% of the total. CDC's 444 reported tests for 2008 to 2017 work out to 41.7 per 1,000 residents (2025 estimate), close to Iowa's 29.4.

From Osage to Orchard, CDC publishes no figure by town: each reads Mitchell County's.

The cities and towns in Mitchell County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Osage3,552−2.2%33.4%
St. Ansgar1,168−0.1%11.0%
Ricevilleextends beyond Mitchell County805−0.7%Counted whole
Stacyville435−4.6%4.1%
McIntire117+3.5%1.1%
Mitchell116−5.7%1.1%
Carpenter92+4.5%0.9%
Orchard65+4.8%0.6%

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). A place that extends beyond Mitchell County is counted whole, so it has no share.

Mitchell County, Homes

Homes in Mitchell County

Mitchell County is a place of houses on their own lots: 88% of its 4,902 homes are detached single-family houses, against 72% across Iowa. The homes are older than Iowa's as a whole: half were built before 1956 (1971 for Iowa), and 53% date from before 1960. Owners live in 80% of the occupied homes (Iowa: 72%), so for most households a test and a fix are their own to order.

Homes in Mitchell County, Iowa, 2019 to 2023
HomesMitchell CountyIowa
Housing units4,9021,427,175
Detached houses88%72%
In buildings of 5 or more3%14%
Mobile homes2%3%
Built before 196053%39%
Built since 200012%21%
Middle year built19561971
Owner-occupied80%72%

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