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Radon Levels in Kossuth County, Iowa

EPA puts Kossuth County in Zone 1, its highest radon zone, and high results are common there: 66.1% of the 434 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

    66.1%

    7.6 pts above IA

    Kossuth
    66.1%
    Iowa
    58.5%

    434 tests, 2008 to 2017

  • Median result

    5.7pCi/L

    Action level reached

    Kossuth
    5.7 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    434

    55th of 99 by tests

    Kossuth
    434
    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

    47 of 99

    Middle half

    Kossuth
    66.1%
    Sioux
    84.2%

    By share, of 99 with 30+ tests

Read a result for Kossuth County

Starts at Kossuth County's median, 5.7 pCi/L

5.7pCi/L

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

EPA’s reading of 5.7 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. Kossuth County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Kossuth County, At a glance

Kossuth County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

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

Reported results by concentration band, Kossuth County, 2008 to 2017, laboratory
Under 2 pCi/L: 14%2 to 4 pCi/L: 20%4 pCi/L and above: 66%

Of 434 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Kossuth County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L6114.1%
2 to 4 pCi/L8619.8%
4 pCi/L and above28766.1%
What these figures count

These are the 434 tests reported to CDC for Kossuth 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

Kossuth County, Compared

Kossuth County radon figures, compared

Calculated by Radon411

More than half: 66.1% of the 434 radon tests reported to CDC for Kossuth County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 47th of 99 Iowa counties with 30 or more tests for the same period. That is 7.6 points above the 58.5% pooled from 99 Iowa counties.

The median result, 5.7 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 49.5 pCi/L. The rest split 14.1% under 2 pCi/L and 19.8% from 2 to 4 (Iowa: 21.8% and 19.7%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 66.1% share point the same way here.

6 of its 9 bordering counties with figures ran higher, led by Winnebago County at 71.9%; Hancock County reported 64.5%. 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 Kossuth County went from 329 tests (2005 to 2014) to 434 (2008 to 2017), the share going from 68.1% to 66.1%.

Nationally, every county with a figure for the same period pools to 35.7%; Kossuth County sits 30.4 points above it. CDC also counts 56 tests taken after mitigation in Kossuth County for the same period: tests in homes where a fix was already in.

Kossuth County against Iowa, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Kossuth County
Kossuth County43466.1%5.7 pCi/LThis county
Iowa, pooled99 counties, pooled95,24558.5%Not pooled−7.6 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−30.4 points
Sioux Countyhighest in the state1,98284.2%10.7 pCi/L+18.1 points
Decatur Countylowest in the state8525.9%2.5 pCi/L−40.2 points
Winnebago County, IAborders it82971.9%6.7 pCi/L+5.8 points
Emmet County, IAborders it42071.0%6.3 pCi/L+4.9 points
Palo Alto County, IAborders it46270.8%5.9 pCi/L+4.7 points
Humboldt County, IAborders it38570.1%7.0 pCi/L+4.0 points
Pocahontas County, IAborders it41768.8%6.4 pCi/L+2.7 points
Wright County, IAborders it29266.8%6.2 pCi/L+0.7 points
Faribault County, MNborders it32365.3%5.3 pCi/L−0.8 points
Martin County, MNborders it40564.9%5.2 pCi/L−1.2 points
Hancock County, IAborders it64064.5%5.5 pCi/L−1.6 points
Where Kossuth County's reported results fell, 2008 to 2017, laboratory, beside Iowa and the United States
ResultKossuth County testsKossuth County shareIowa shareU.S. shareAgainst Iowa
Under 2 pCi/L6114.1%21.8%39.6%−7.7 points
2 to 4 pCi/L8619.8%19.7%24.7%+0.1 points
4 pCi/L and above28766.1%58.5%35.7%+7.6 points
Kossuth 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
Marion County42 of 991,15167.3%6.0 pCi/L
Osceola County43 of 9912267.2%6.8 pCi/L
Grundy County44 of 9950166.9%6.9 pCi/L
Wright County45 of 9929266.8%6.2 pCi/L
Winneshiek County46 of 991,07166.4%6.2 pCi/L
Kossuth County47 of 9943466.1%5.7 pCi/L
Warren County48 of 991,51366.0%6.3 pCi/L
Adams County49 of 998165.4%6.1 pCi/L
Hancock County50 of 9964064.5%5.5 pCi/L
Polk County51 of 9910,94564.4%5.6 pCi/L
Hamilton County52 of 9925264.3%5.5 pCi/L
Kossuth County ten-year laboratory totals, against Iowa's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestIowa, pooledChange from the row before
2008 to 201743466.1%5.7 pCi/L49.5 pCi/L58.5%−1.1 points
2007 to 201638767.2%6.0 pCi/L49.5 pCi/L58.6%−1.5 points
2006 to 201536468.7%6.3 pCi/L49.5 pCi/L59.4%+0.6 points
2005 to 201432968.1%6.4 pCi/L49.5 pCi/L59.6%First on file

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

Kossuth County, Geology

The ground under Kossuth County

Predicted

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

USGS's geologic areas under Kossuth County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Des Moines LobeCalcareous loamy till derived from shale, limestone, dolomite, sandstone.High12100%

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

Kossuth County beside the ground around it

On high-potential ground Kossuth County is close to Iowa as a whole: 100% of its land against 98.8%. Of the 9 counties that border it, none has as large a share of high-potential ground; Emmet County comes nearest at 100%.

Share of land by USGS radon potential: Kossuth County, the 9 counties bordering it and Iowa
AreaEPA zoneLow potentialModerate potentialHigh potential
Kossuth CountyZone 1NoneNone100%
Humboldt CountyZone 1NoneNone100%
Palo Alto CountyZone 1NoneNone100%
Hancock CountyZone 1NoneNone100%
Emmet CountyZone 1NoneNone100%
Winnebago CountyZone 1NoneNone100%
Pocahontas CountyZone 1NoneNone100%
Wright CountyZone 1NoneNone100%
Faribault County, MNZone 1NoneNone100%
Martin County, MNZone 1NoneNone100%
Iowa99 counties, pooled by land areaVariesNone1.2%98.8%

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

Local help

Kossuth County, Local resources

Radon testing and mitigation in Kossuth 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

Kossuth County, Questions

Questions about radon in Kossuth County

Are radon levels high in Kossuth County?

Over the 2008 to 2017 laboratory totals, 66.1% of the radon tests reported to CDC for Kossuth County, Iowa were at or above 4 pCi/L, and the median reported pre-mitigation result was 5.7 pCi/L. Of 99 Iowa counties with 30 or more tests for the same period, 46 reported a higher share; pooled, the state comes to 58.5%.

Which counties border Kossuth County?

Kossuth County borders 9 counties: Humboldt County, IA, Palo Alto County, IA, Hancock County, IA, Emmet County, IA, Winnebago County, IA, Pocahontas County, IA, Wright County, IA, Faribault County, MN and Martin County, MN.

Products

Kossuth County, Products

Testing a home in Kossuth County

In Kossuth County, 66.1% of 434 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 Kossuth 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

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

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Kossuth County, Bordering counties

Counties bordering Kossuth County

Calculated by Radon411

Kossuth County, Cities and towns

Cities and towns in Kossuth County

About 14,322 people live in Kossuth County by the Census Bureau's estimate for July 1, 2025, 472 fewer than in 2020 (−3.2%). That works out to 15 people per square mile of land. Its largest town, Algona, has 5,309 residents, 37.1% of the total. CDC's 434 reported tests for 2008 to 2017 work out to 30.3 per 1,000 residents (2025 estimate), close to Iowa's 29.4.

From Algona to Ledyard, CDC publishes no figure by town: each reads Kossuth County's.

The 12 largest cities and towns in Kossuth County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Algona5,309−3.1%37.1%
West Bendextends beyond Kossuth County775−1.8%Counted whole
Bancroft673−3.3%4.7%
Swea City541−4.1%3.8%
Titonka492−3.7%3.4%
Whittemore476−3.8%3.3%
Burt399−3.9%2.8%
Wesley379−3.6%2.6%
Lakota259−3.0%1.8%
Fenton250−6.4%1.7%
Lu Verneextends beyond Kossuth County246−3.1%Counted whole
Lone Rock142−3.4%1.0%
  • Ledyard

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

Kossuth County, Homes

Homes in Kossuth County

Kossuth County is a place of houses on their own lots: 85% of its 7,220 homes are detached single-family houses, against 72% across Iowa. The homes are older than Iowa's as a whole: half were built before 1961 (1971 for Iowa), and 49% date from before 1960. Owners live in 75% of the occupied homes (Iowa: 72%), so for most households a test and a fix are their own to order.

Homes in Kossuth County, Iowa, 2019 to 2023
HomesKossuth CountyIowa
Housing units7,2201,427,175
Detached houses85%72%
In buildings of 5 or more8%14%
Mobile homesunder 1%3%
Built before 196049%39%
Built since 200014%21%
Middle year built19611971
Owner-occupied75%72%

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