Skip to content
RADON411

Locations and reports

Radon Levels in Wayne County, Iowa

EPA puts Wayne County in Zone 1, its highest radon zone, and 34.8% of its 46 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

How to test this homeFind a certified tester

  • Share at 4+ pCi/L

    34.8%

    23.7 pts below IA

    Wayne
    34.8%
    Iowa
    58.5%

    46 tests, 2008 to 2017

  • Median result

    3.0pCi/L

    Below action level

    Wayne
    3.0 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    46

    99th of 99 by tests

    Wayne
    46
    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

    94 of 99

    Lowest quarter

    Wayne
    34.8%
    Sioux
    84.2%

    By share, of 99 with 30+ tests

Read a result for Wayne County

Starts at Wayne County's median, 3.0 pCi/L

3.0pCi/L

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

EPA’s reading of 3.0 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. Wayne County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Wayne County, At a glance

Wayne County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Wayne 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 77% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

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

Reported results by concentration band, Wayne County, 2008 to 2017, laboratory
Under 2 pCi/L: 35%2 to 4 pCi/L: 30%4 pCi/L and above: 35%

Of 46 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Wayne County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L1634.8%
2 to 4 pCi/L1430.4%
4 pCi/L and above1634.8%
What these figures count

These are the 46 tests reported to CDC for Wayne 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

Wayne County, Compared

Wayne County radon figures, compared

Calculated by Radon411

In Wayne County, about 3 in 10 reported tests over the 2008 to 2017 laboratory totals (16 of 46) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 0.9 points lower. Across 99 Iowa counties pooled together, 58.5% of tests reached that level, so Wayne County runs 23.7 points below its state.

Of 5 neighbours with a figure, 3 reported a larger share at or above 4 pCi/L and 2 a smaller one; the spread is 25.9% (Decatur County) to 45.8% (Clarke County). By share, Wayne County is 94th of 99 Iowa counties with 30 or more tests for the same period.

Half the tests came in under 3.0 pCi/L and half over it; the single highest reached 14.5 pCi/L. Below the action level, 16 tests (34.8%) came in under 2 pCi/L, against 21.8% statewide, and 14 tests (30.4%) fell between 2 and 4, against 19.7% statewide.

Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 34.8% share point the same way here. USGS geology rates 77% of the county's land high radon potential.

CDC's ten-year totals for Wayne County went from 47 tests (2005 to 2014) to 46 (2008 to 2017), the share going from 40.4% to 34.8%.

Wayne County against Iowa, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Wayne County
Wayne County4634.8%3.0 pCi/LThis county
Iowa, pooled99 counties, pooled95,24558.5%Not pooled+23.7 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+0.9 points
Sioux Countyhighest in the state1,98284.2%10.7 pCi/L+49.4 points
Ringgold Countylowest in the state8728.7%2.6 pCi/L−6.1 points
Clarke County, IAborders it12045.8%3.5 pCi/L+11.0 points
Appanoose County, IAborders it11745.3%3.7 pCi/L+10.5 points
Lucas County, IAborders it8439.3%3.3 pCi/L+4.5 points
Monroe County, IAborders it5933.9%2.9 pCi/L−0.9 points
Putnam County, MOborders it933.3%1.8 pCi/L−1.5 points
Mercer County, MOborders it1127.3%1.7 pCi/L−7.5 points
Decatur County, IAborders it8525.9%2.5 pCi/L−8.9 points
Where Wayne County's reported results fell, 2008 to 2017, laboratory, beside Iowa and the United States
ResultWayne County testsWayne County shareIowa shareU.S. shareAgainst Iowa
Under 2 pCi/L1634.8%21.8%39.6%+13.0 points
2 to 4 pCi/L1430.4%19.7%24.7%+10.7 points
4 pCi/L and above1634.8%58.5%35.7%−23.7 points
Wayne 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
Davis County89 of 998542.4%3.1 pCi/L
Johnson County90 of 997,32141.6%3.2 pCi/L
Linn County91 of 999,39539.7%3.0 pCi/L
Lucas County92 of 998439.3%3.3 pCi/L
Wapello County93 of 9928735.9%2.7 pCi/L
Wayne County94 of 994634.8%3.0 pCi/L
Monroe County95 of 995933.9%2.9 pCi/L
Jefferson County96 of 9984133.5%2.6 pCi/L
Van Buren County97 of 995632.1%2.3 pCi/L
Ringgold County98 of 998728.7%2.6 pCi/L
Decatur County99 of 998525.9%2.5 pCi/L
Wayne County ten-year laboratory totals, against Iowa's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestIowa, pooledChange from the row before
2008 to 20174634.8%3.0 pCi/L14.5 pCi/L58.5%−0.6 points
2007 to 20164835.4%3.0 pCi/L14.5 pCi/L58.6%−5.0 points
2006 to 20154740.4%3.6 pCi/L14.5 pCi/L59.4%Level
2005 to 20144740.4%3.6 pCi/L14.5 pCi/L59.6%First on file

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

Wayne County, Geology

The ground under Wayne County

Predicted

Most of the ground under Wayne County is one class on USGS's geologic map: 77.1% of its land is high radon potential, with 22.9% moderate. The map puts 77.1% of Wayne County in the area it calls Loess-Covered Drift Plains and 22.9% in Dissected Till Plains. USGS gives the first a radon index of 13, in the high band (12 to 17), and the second 11, in the moderate band (9 to 11).

USGS's geologic areas under Wayne County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Loess-Covered Drift PlainsPre-Illinoian and Illinoian glacial deposits, and loess.High1377.1%
Dissected Till PlainsTill-covered Pennsylvanian sandstone, shale, and limestone.Moderate1122.9%

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

Wayne County beside the ground around it

Iowa as a whole has more high-potential ground than Wayne County: 98.8% of its land, against 77.1% here. Of the 7 counties that border it, 4 have more high-potential ground, Clarke County the most at 100%.

Share of land by USGS radon potential: Wayne County, the 7 counties bordering it and Iowa
AreaEPA zoneLow potentialModerate potentialHigh potential
Wayne CountyZone 1None22.9%77.1%
Lucas CountyZone 1NoneNone100%
Appanoose CountyZone 1None46.5%53.5%
Decatur CountyZone 1None8.6%91.4%
Putnam County, MOZone 2None100%None
Mercer County, MOZone 2None100%None
Clarke CountyZone 1NoneNone100%
Monroe CountyZone 1NoneNone100%
Iowa99 counties, pooled by land areaVariesNone1.2%98.8%

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

Local help

Wayne County, Local resources

Radon testing and mitigation in Wayne 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

Wayne County, Questions

Questions about radon in Wayne County

Are radon levels high in Wayne County?

Over the 2008 to 2017 laboratory totals, 34.8% of the radon tests reported to CDC for Wayne County, Iowa were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.0 pCi/L. Of 99 Iowa counties with 30 or more tests for the same period, 93 reported a higher share; pooled, the state comes to 58.5%.

Which counties border Wayne County?

Wayne County borders 7 counties: Lucas County, IA, Appanoose County, IA, Decatur County, IA, Putnam County, MO, Mercer County, MO, Clarke County, IA and Monroe County, IA.

Products

Wayne County, Products

Testing a home in Wayne County

In Wayne County, 34.8% of 46 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 Wayne 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

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

Explore

Wayne County, Bordering counties

Counties bordering Wayne County

Calculated by Radon411

Wayne County, Cities and towns

Cities and towns in Wayne County

The Census Bureau estimates 6,738 residents in Wayne County for July 1, 2025, 231 more than in 2020 (+3.6%). That works out to 13 people per square mile of land. Its largest town, Corydon, has 1,711 residents, 25.4% of the total. Together its 8 incorporated places hold 54.0% of those residents; the other 46.0% live outside any of them. Reported testing is thin here: 46 tests over 2008 to 2017, or 6.8 for every 1,000 residents (2025 estimate), where Iowa as a whole comes to 29.4.

From Corydon to Millerton, CDC publishes no figure by town: each reads Wayne County's.

The cities and towns in Wayne County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Corydon1,711+12.3%25.4%
Seymour641+0.8%9.5%
Humeston471+1.1%7.0%
Allerton429Level6.4%
Lineville192+0.5%2.8%
Promise City90+1.1%1.3%
Clio67+1.5%1.0%
Millerton38Level0.6%

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).

Wayne County, Homes

Homes in Wayne County

Wayne County is a place of houses on their own lots: 83% of its 3,021 homes are detached single-family houses, against 72% across Iowa. Half of its homes were built before 1969, close to Iowa's 1971: 44% date from before 1960 and 18% from 2000 or later. 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 Wayne County, Iowa, 2019 to 2023
HomesWayne CountyIowa
Housing units3,0211,427,175
Detached houses83%72%
In buildings of 5 or moreunder 1%14%
Mobile homes8%3%
Built before 196044%39%
Built since 200018%21%
Middle year built19691971
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.