Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
Locations and reports
Radon Levels in Warren County, Iowa
EPA puts Warren County in Zone 1, its highest radon zone, and high results are common there: 66.0% of the 1,513 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
Share at 4+ pCi/L
66.0%
7.5 pts above IA
- Warren
- 66.0%
- Iowa
- 58.5%
1,513 tests, 2008 to 2017
Median result
6.3pCi/L
Action level reached
- Warren
- 6.3 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
1,513
13th of 99 by tests
- Warren
- 1,513
- Polk
- 10,945
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in Iowa
48 of 99
Middle half
- Warren
- 66.0%
- Sioux
- 84.2%
By share, of 99 with 30+ tests
Read a result for Warren County
Starts at Warren County's median, 6.3 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 6.3 pCi/L
At or above 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 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. Warren County's median reported result, 2008 to 2017.
The data
Warren County, At a glance
Warren County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Warren County in
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 Warren County, 2008 to 2017, laboratory
Under 2 pCi/L: 16%2 to 4 pCi/L: 18%4 pCi/L and above: 66%
Of 1,513 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 240 | 15.9% |
| 2 to 4 pCi/L | 275 | 18.2% |
| 4 pCi/L and above | 998 | 66.0% |
What these figures count
These are the 1,513 tests reported to CDC for Warren 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).
Warren County, Compared
Warren County radon figures, compared
Calculated by Radon411More than half: 66.0% of the 1,513 radon tests reported to CDC for Warren County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 48th of 99 Iowa counties with 30 or more tests for the same period. That is 7.5 points above the 58.5% pooled from 99 Iowa counties.
The median result, 6.3 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 92.8 pCi/L. The rest split 15.9% under 2 pCi/L and 18.2% from 2 to 4 (Iowa: 21.8% and 19.7%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 66.0% share point the same way here.
1 of its 6 bordering counties with figures ran higher, led by Marion County at 67.3%; Lucas County reported 39.3%. 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 Warren County went from 1,189 tests (2005 to 2014) to 1,513 (2008 to 2017), the share going from 68.6% to 66.0%.
Nationally, every county with a figure for the same period pools to 35.7%; Warren County sits 30.3 points above it. CDC also counts 165 tests taken after mitigation in Warren County for the same period: tests in homes where a fix was already in.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Warren County, Geology
The ground under Warren County
PredictedUSGS's geologic map puts all of Warren County's mapped land in one class: high radon potential. All of it lies in the area the map calls Loess-Covered Drift Plains, to which USGS gives a radon index of 13, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Loess-Covered Drift Plains | Pre-Illinoian and Illinoian glacial deposits, and loess. | High | 13 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Warren County beside the ground around it
On high-potential ground Warren 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; Clarke County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Warren County, Local resources
Radon testing and mitigation in Warren County
Listed radon businesses with an address in Warren County:
- Iowa HHS Radon ProgramIowa HHS Radon Program, run by Iowa Department of Health and Human Services, licenses or certifies radon professionals, offers free or discounted test kits and states the rule for disclosing radon when a home is sold, and answers questions about testing and mitigation in Iowa.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
You can reach the Hotline by calling 1-800-383-5992 to order low-cost radon test kits and find answers to your radon questions.
- Compare kits
- Professionals in Iowa185 professionals are listed in Iowa.
Listed radon professionals by town: Des Moines, West Des Moines, Indianola, Norwalk, Hartford
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
Warren County, Questions
Questions about radon in Warren County
Are radon levels high in Warren County?
Over the 2008 to 2017 laboratory totals, 66.0% of the radon tests reported to CDC for Warren County, Iowa were at or above 4 pCi/L, and the median reported pre-mitigation result was 6.3 pCi/L. Of 99 Iowa counties with 30 or more tests for the same period, 47 reported a higher share; pooled, the state comes to 58.5%.
Which counties border Warren County?
Warren County borders 6 counties: Lucas County, Clarke County, Madison County, Marion County, Polk County and Dallas County.
Products
Warren County, Products
Testing a home in Warren County
In Warren County, 66.0% of 1,513 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 Warren 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
MonitorINKBIRD
INK-RD3 battery radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Screen
First reading: Within 24 hours
Short-term kit
RA400 short-term liquid scintillation radon test kit, lab fee included
- Lab fee included
Method: Liquid scintillation
In home: 48 to 96 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Warren County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Warren County
Explore
Warren County, Bordering counties
Counties bordering Warren County
Calculated by Radon411- Radon levels in Marion CountyEPA zone 1
67.3%at or above 4 pCi/L
Median 6.0 pCi/L · 1,151 tests · 1.3 points above Warren County
- Radon levels in Polk CountyEPA zone 1
64.4%at or above 4 pCi/L
Median 5.6 pCi/L · 10,945 tests · 1.6 points below Warren County
- Radon levels in Madison CountyEPA zone 1
62.3%at or above 4 pCi/L
Median 6.0 pCi/L · 318 tests · 3.7 points below Warren County
- Radon levels in Dallas CountyEPA zone 1
58.5%at or above 4 pCi/L
Median 4.9 pCi/L · 2,352 tests · 7.5 points below Warren County
- Radon levels in Clarke CountyEPA zone 1
45.8%at or above 4 pCi/L
Median 3.5 pCi/L · 120 tests · 20.2 points below Warren County
- Radon levels in Lucas CountyEPA zone 1
39.3%at or above 4 pCi/L
Median 3.3 pCi/L · 84 tests · 26.7 points below Warren County
Warren County, Cities and towns
Cities and towns in Warren County
Warren County is growing: the Census Bureau puts it at 57,331 residents on July 1, 2025, up 9.0% from 52,597 in 2020. That works out to 101 people per square mile of land. Des Moines, the largest place on its list (212,086 residents in all), extends beyond Warren County, so no share of the total is worked out for it. CDC's 1,513 reported tests for 2008 to 2017 work out to 26.4 per 1,000 residents (2025 estimate), close to Iowa's 29.4.
From Des Moines to Bevington, CDC publishes no figure by town: each reads Warren County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Des Moinesextends beyond Warren County | 212,086 | −0.7% | Counted whole |
| West Des Moinesextends beyond Warren County | 74,224 | +7.6% | Counted whole |
| Indianola | 16,829 | +6.0% | 29.4% |
| Norwalkextends beyond Warren County | 15,004 | +16.7% | Counted whole |
| Carlisleextends beyond Warren County | 4,532 | +8.3% | Counted whole |
| Milo | 784 | +0.9% | 1.4% |
| Hartford | 747 | +1.9% | 1.3% |
| Cumming | 560 | +28.4% | 1.0% |
| New Virginia | 507 | +1.4% | 0.9% |
| Martensdale | 426 | −0.5% | 0.7% |
| Lacona | 344 | −0.3% | 0.6% |
| St. Marys | 124 | +5.1% | 0.2% |
Places in Warren County with a city page: 1 of 1
- Ackworth
- Spring Hill
- Sandyville
- Bevington (part)
16 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 Warren County is counted whole, so it has no share.
Warren County, Homes
Homes in Warren County
Warren County is a place of houses on their own lots: 77% of its 21,473 homes are detached single-family houses, against 72% across Iowa. Much of Warren County is recent building: 34% of its homes have gone up since 2000 and the middle year built is 1984, against 1971 for Iowa. Owners live in 83% of the occupied homes (Iowa: 72%), so for most households a test and a fix are their own to order.
| Homes | Warren County | Iowa |
|---|---|---|
| Housing units | 21,473 | 1,427,175 |
| Detached houses | 77% | 72% |
| In buildings of 5 or more | 10% | 14% |
| Mobile homes | 3% | 3% |
| Built before 1960 | 20% | 39% |
| Built since 2000 | 34% | 21% |
| Middle year built | 1984 | 1971 |
| Owner-occupied | 83% | 72% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.