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 Crawford County, Iowa
EPA puts Crawford County in Zone 1, its highest radon zone, and high results are common there: 74.8% of the 373 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
74.8%
16.3 pts above IA
- Crawford
- 74.8%
- Iowa
- 58.5%
373 tests, 2008 to 2017
Median result
7.0pCi/L
Action level reached
- Crawford
- 7.0 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
373
63rd of 99 by tests
- Crawford
- 373
- 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
11 of 99
Top quarter
- Crawford
- 74.8%
- Sioux
- 84.2%
By share, of 99 with 30+ tests
Read a result for Crawford County
Starts at Crawford County's median, 7.0 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 7.0 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. Crawford County's median reported result, 2008 to 2017.
The data
Crawford County, At a glance
Crawford County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Crawford 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 Crawford County, 2008 to 2017, laboratory
Under 2 pCi/L: 11%2 to 4 pCi/L: 14%4 pCi/L and above: 75%
Of 373 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 43 | 11.5% |
| 2 to 4 pCi/L | 51 | 13.7% |
| 4 pCi/L and above | 279 | 74.8% |
What these figures count
These are the 373 tests reported to CDC for Crawford 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).
Crawford County, Compared
Crawford County radon figures, compared
Calculated by Radon411More than half: 74.8% of the 373 radon tests reported to CDC for Crawford County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 11th of 99 Iowa counties with 30 or more tests for the same period. That is 16.3 points above the 58.5% pooled from 99 Iowa counties.
The median result, 7.0 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 65.8 pCi/L. The rest split 11.5% under 2 pCi/L and 13.7% from 2 to 4 (Iowa: 21.8% and 19.7%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 74.8% share point the same way here.
4 of its 8 bordering counties with figures ran higher, led by Shelby County at 78.4%; Woodbury County reported 69.2%. 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 Crawford County went from 227 tests (2005 to 2014) to 373 (2008 to 2017), the share going from 80.2% to 74.8%.
Nationally, every county with a figure for the same period pools to 35.7%; Crawford County sits 39.1 points above it. CDC also counts 7 tests taken after mitigation in Crawford 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.
Crawford County, Geology
The ground under Crawford County
PredictedUSGS's geologic map puts all of Crawford 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.
Crawford County beside the ground around it
On high-potential ground Crawford County is close to Iowa as a whole: 100% of its land against 98.8%. Of the 8 counties that border it, none has as large a share of high-potential ground; Audubon County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Crawford County, Local resources
Radon testing and mitigation in Crawford 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
Crawford County, Questions
Questions about radon in Crawford County
Are radon levels high in Crawford County?
Over the 2008 to 2017 laboratory totals, 74.8% of the radon tests reported to CDC for Crawford County, Iowa were at or above 4 pCi/L, and the median reported pre-mitigation result was 7.0 pCi/L. Of 99 Iowa counties with 30 or more tests for the same period, 10 reported a higher share; pooled, the state comes to 58.5%.
Which counties border Crawford County?
Crawford County borders 8 counties: Shelby County, Ida County, Sac County, Carroll County, Monona County, Audubon County, Harrison County and Woodbury County.
Products
Crawford County, Products
Testing a home in Crawford County
In Crawford County, 74.8% of 373 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 Crawford 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
RadonPro Wi-Fi radon monitor with a built-in Geiger counter
- C-NRPP 2024/25: Not included
- Plug-in
- Wi-Fi
- Alarm
- Screen, app
First reading: Within 5 minutes
Short-term kitFirst Alert
RD1 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 2 to 4 days
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Crawford County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Crawford County
Explore
Crawford County, Bordering counties
Counties bordering Crawford County
Calculated by Radon411- Radon levels in Shelby CountyEPA zone 1
78.4%at or above 4 pCi/L
Median 9.0 pCi/L · 857 tests · 3.6 points above Crawford County
- Radon levels in Audubon CountyEPA zone 1
78.3%at or above 4 pCi/L
Median 9.5 pCi/L · 189 tests · 3.5 points above Crawford County
- Radon levels in Carroll CountyEPA zone 1
77.6%at or above 4 pCi/L
Median 7.8 pCi/L · 594 tests · 2.8 points above Crawford County
- Radon levels in Sac CountyEPA zone 1
76.6%at or above 4 pCi/L
Median 7.0 pCi/L · 491 tests · 1.8 points above Crawford County
- Radon levels in Monona CountyEPA zone 1
74.6%at or above 4 pCi/L
Median 7.0 pCi/L · 603 tests · 0.2 points below Crawford County
- Radon levels in Ida CountyEPA zone 1
71.7%at or above 4 pCi/L
Median 7.4 pCi/L · 399 tests · 3.1 points below Crawford County
- Radon levels in Harrison CountyEPA zone 1
69.8%at or above 4 pCi/L
Median 6.2 pCi/L · 367 tests · 5.0 points below Crawford County
- Radon levels in Woodbury CountyEPA zone 1
69.2%at or above 4 pCi/L
Median 6.1 pCi/L · 3,541 tests · 5.6 points below Crawford County
Crawford County, Cities and towns
Cities and towns in Crawford County
About 16,237 people live in Crawford County by the Census Bureau's estimate for July 1, 2025, 250 fewer than in 2020 (−1.5%). That works out to 23 people per square mile of land. Denison alone is home to 8,214 of them, 50.6% of the total. CDC's 373 reported tests for 2008 to 2017 work out to 23.0 per 1,000 residents (2025 estimate), close to Iowa's 29.4.
From Denison to Buck Grove, CDC publishes no figure by town: each reads Crawford County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Denison | 8,214 | −1.7% | 50.6% |
| Dunlapextends beyond Crawford County | 1,030 | −1.5% | Counted whole |
| Schleswig | 817 | −1.7% | 5.0% |
| Manilla | 748 | −2.9% | 4.6% |
| Charter Oak | 513 | −3.0% | 3.2% |
| Dow City | 471 | −2.7% | 2.9% |
| Vail | 380 | −2.8% | 2.3% |
| Westside | 280 | −2.4% | 1.7% |
| Kiron | 263 | −2.2% | 1.6% |
| Deloit | 241 | −2.4% | 1.5% |
| Ricketts | 110 | −1.8% | 0.7% |
| Arion | 98 | Level | 0.6% |
- Aspinwall
- Buck Grove
14 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 Crawford County is counted whole, so it has no share.
Crawford County, Homes
Homes in Crawford County
Crawford County is a place of houses on their own lots: 77% of its 6,852 homes are detached single-family houses, against 72% across Iowa. The homes are older than Iowa's as a whole: half were built before 1963 (1971 for Iowa), and 47% date from before 1960. Owners live in 79% of the occupied homes (Iowa: 72%), so for most households a test and a fix are their own to order.
| Homes | Crawford County | Iowa |
|---|---|---|
| Housing units | 6,852 | 1,427,175 |
| Detached houses | 77% | 72% |
| In buildings of 5 or more | 6% | 14% |
| Mobile homes | 7% | 3% |
| Built before 1960 | 47% | 39% |
| Built since 2000 | 6% | 21% |
| Middle year built | 1963 | 1971 |
| Owner-occupied | 79% | 72% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.