Long-term kit
RL416 long-term radon test kit, lab fee included
- Lab fee included
Method: Alpha track
In home: 90 days to 12 months
Locations and reports
Radon Levels in Guthrie County, Iowa
EPA puts Guthrie County in Zone 1, its highest radon zone, and high results are common there: 70.8% of the 257 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
70.8%
12.3 pts above IA
- Guthrie
- 70.8%
- Iowa
- 58.5%
257 tests, 2008 to 2017
Median result
6.9pCi/L
Action level reached
- Guthrie
- 6.9 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
257
75th of 99 by tests
- Guthrie
- 257
- 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
24 of 99
Top quarter
- Guthrie
- 70.8%
- Sioux
- 84.2%
By share, of 99 with 30+ tests
Read a result for Guthrie County
Starts at Guthrie County's median, 6.9 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 6.9 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. Guthrie County's median reported result, 2008 to 2017.
The data
Guthrie County, At a glance
Guthrie County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Guthrie 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 Guthrie County, 2008 to 2017, laboratory
Under 2 pCi/L: 10%2 to 4 pCi/L: 19%4 pCi/L and above: 71%
Of 257 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 27 | 10.5% |
| 2 to 4 pCi/L | 48 | 18.7% |
| 4 pCi/L and above | 182 | 70.8% |
What these figures count
These are the 257 tests reported to CDC for Guthrie 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).
Guthrie County, Compared
Guthrie County radon figures, compared
Calculated by Radon411More than half: 70.8% of the 257 radon tests reported to CDC for Guthrie County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 24th of 99 Iowa counties with 30 or more tests for the same period. That is 12.3 points above the 58.5% pooled from 99 Iowa counties.
The median result, 6.9 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 222.5 pCi/L. The rest split 10.5% under 2 pCi/L and 18.7% from 2 to 4 (Iowa: 21.8% and 19.7%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 70.8% share point the same way here.
5 of its 7 bordering counties with figures ran higher, led by Audubon County at 78.3%; Dallas County reported 58.5%. 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 Guthrie County went from 230 tests (2005 to 2014) to 257 (2008 to 2017), the share going from 74.8% to 70.8%.
Nationally, every county with a figure for the same period pools to 35.7%; Guthrie County sits 35.1 points above it. CDC also counts 20 tests taken after mitigation in Guthrie 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.
Guthrie County, Geology
The ground under Guthrie County
PredictedUSGS's geologic map puts all of Guthrie County's mapped land in one class: high radon potential. The map puts 68.6% of Guthrie County in the area it calls Loess-Covered Drift Plains and 31.4% in Des Moines Lobe. USGS gives the first a radon index of 13 and the second 12, both 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 | 68.6% |
| Des Moines Lobe | Calcareous loamy till derived from shale, limestone, dolomite, sandstone. | High | 12 | 31.4% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Guthrie County beside the ground around it
On high-potential ground Guthrie County is close to Iowa as a whole: 100% of its land against 98.8%. Of the 7 counties that border it, none has as large a share of high-potential ground; Adair County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Guthrie County, Local resources
Radon testing and mitigation in Guthrie 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.
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
Guthrie County, Questions
Questions about radon in Guthrie County
Are radon levels high in Guthrie County?
Over the 2008 to 2017 laboratory totals, 70.8% of the radon tests reported to CDC for Guthrie County, Iowa were at or above 4 pCi/L, and the median reported pre-mitigation result was 6.9 pCi/L. Of 99 Iowa counties with 30 or more tests for the same period, 23 reported a higher share; pooled, the state comes to 58.5%.
Which counties border Guthrie County?
Guthrie County borders 7 counties: Audubon County, Greene County, Dallas County, Carroll County, Cass County, Adair County and Madison County.
Products
Guthrie County, Products
Testing a home in Guthrie County
In Guthrie County, 70.8% of 257 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 Guthrie 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
Monitor
RadonEye RD200 plug-in continuous radon monitor
- C-NRPP 2024/25: Approved
- Plug-in
- Bluetooth
- Alarm
- Screen, app
Method: Ion chamber
First reading: Within 10 minutes
Short-term kit
Radon Short Term Test Kit short-term charcoal radon test kit, lab fee included
- Lab fee included
Method: Charcoal
In home: 2 to 7 days
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Guthrie County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Guthrie County
Explore
Guthrie County, Bordering counties
Counties bordering Guthrie County
Calculated by Radon411- Radon levels in Audubon CountyEPA zone 1
78.3%at or above 4 pCi/L
Median 9.5 pCi/L · 189 tests · 7.5 points above Guthrie County
- Radon levels in Carroll CountyEPA zone 1
77.6%at or above 4 pCi/L
Median 7.8 pCi/L · 594 tests · 6.8 points above Guthrie County
- Radon levels in Cass CountyEPA zone 1
77.4%at or above 4 pCi/L
Median 8.1 pCi/L · 327 tests · 6.6 points above Guthrie County
- Radon levels in Adair CountyEPA zone 1
72.4%at or above 4 pCi/L
Median 9.3 pCi/L · 98 tests · 1.6 points above Guthrie County
- Radon levels in Greene CountyEPA zone 1
71.3%at or above 4 pCi/L
Median 6.2 pCi/L · 143 tests · 0.5 points above Guthrie County
- Radon levels in Madison CountyEPA zone 1
62.3%at or above 4 pCi/L
Median 6.0 pCi/L · 318 tests · 8.5 points below Guthrie County
- Radon levels in Dallas CountyEPA zone 1
58.5%at or above 4 pCi/L
Median 4.9 pCi/L · 2,352 tests · 12.3 points below Guthrie County
Guthrie County, Cities and towns
Cities and towns in Guthrie County
The Census Bureau estimates 10,782 residents in Guthrie County for July 1, 2025, 168 more than in 2020 (+1.6%). That works out to 18 people per square mile of land. Stuart, the largest place on its list (1,882 residents in all), extends beyond Guthrie County, so no share of the total is worked out for it. CDC's 257 reported tests for 2008 to 2017 work out to 23.8 per 1,000 residents (2025 estimate), close to Iowa's 29.4.
From Stuart to Jamaica, CDC publishes no figure by town: each reads Guthrie County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Stuartextends beyond Guthrie County | 1,882 | +4.8% | Counted whole |
| Guthrie Center | 1,583 | Level | 14.7% |
| Coon Rapidsextends beyond Guthrie County | 1,251 | −3.9% | Counted whole |
| Panora | 1,094 | +0.6% | 10.1% |
| Adairextends beyond Guthrie County | 776 | −2.1% | Counted whole |
| Bayard | 401 | −1.0% | 3.7% |
| Caseyextends beyond Guthrie County | 386 | +0.5% | Counted whole |
| Menlo | 346 | +0.6% | 3.2% |
| Yale | 264 | −0.8% | 2.4% |
| Bagley | 228 | −1.3% | 2.1% |
| Jamaica | 197 | +1.5% | 1.8% |
11 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 Guthrie County is counted whole, so it has no share.
Guthrie County, Homes
Homes in Guthrie County
Guthrie County is a place of houses on their own lots: 91% of its 5,782 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 15% from 2000 or later. 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 | Guthrie County | Iowa |
|---|---|---|
| Housing units | 5,782 | 1,427,175 |
| Detached houses | 91% | 72% |
| In buildings of 5 or more | 4% | 14% |
| Mobile homes | 2% | 3% |
| Built before 1960 | 44% | 39% |
| Built since 2000 | 15% | 21% |
| Middle year built | 1969 | 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.