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 Jasper County, Iowa
EPA puts Jasper County in Zone 1, its highest radon zone, and high results are common there: 73.3% of the 746 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
73.3%
14.8 pts above IA
- Jasper
- 73.3%
- Iowa
- 58.5%
746 tests, 2008 to 2017
Median result
8.2pCi/L
Action level reached
- Jasper
- 8.2 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
746
30th of 99 by tests
- Jasper
- 746
- 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
15 of 99
Top quarter
- Jasper
- 73.3%
- Sioux
- 84.2%
By share, of 99 with 30+ tests
Read a result for Jasper County
Starts at Jasper County's median, 8.2 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 8.2 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. Jasper County's median reported result, 2008 to 2017.
The data
Jasper County, At a glance
Jasper County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Jasper 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 Jasper County, 2008 to 2017, laboratory
Under 2 pCi/L: 15%2 to 4 pCi/L: 12%4 pCi/L and above: 73%
Of 746 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 111 | 14.9% |
| 2 to 4 pCi/L | 88 | 11.8% |
| 4 pCi/L and above | 547 | 73.3% |
What these figures count
These are the 746 tests reported to CDC for Jasper 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).
Jasper County, Compared
Jasper County radon figures, compared
Calculated by Radon411More than half: 73.3% of the 746 radon tests reported to CDC for Jasper County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 15th of 99 Iowa counties with 30 or more tests for the same period. That is 14.8 points above the 58.5% pooled from 99 Iowa counties.
The median result, 8.2 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 150.2 pCi/L. The rest split 14.9% under 2 pCi/L and 11.8% from 2 to 4 (Iowa: 21.8% and 19.7%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 73.3% share point the same way here.
No bordering county with a figure for the same period reported a higher share; the closest is Poweshiek County at 70.6%, the lowest Story County at 59.9%. 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 Jasper County went from 643 tests (2005 to 2014) to 746 (2008 to 2017), the share going from 73.6% to 73.3%.
Nationally, every county with a figure for the same period pools to 35.7%; Jasper County sits 37.6 points above it. CDC also counts 78 tests taken after mitigation in Jasper 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.
Jasper County, Geology
The ground under Jasper County
PredictedUSGS's geologic map puts all of Jasper County's mapped land in one class: high radon potential. 97.4% 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 | 97.4% |
| Des Moines Lobe | Calcareous loamy till derived from shale, limestone, dolomite, sandstone. | High | 12 | 2.6% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Jasper County beside the ground around it
On high-potential ground Jasper 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; Mahaska County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Jasper County, Local resources
Radon testing and mitigation in Jasper County
Listed radon businesses with an address in Jasper 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: Prairie City
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
Jasper County, Questions
Questions about radon in Jasper County
Are radon levels high in Jasper County?
Over the 2008 to 2017 laboratory totals, 73.3% of the radon tests reported to CDC for Jasper County, Iowa were at or above 4 pCi/L, and the median reported pre-mitigation result was 8.2 pCi/L. Of 99 Iowa counties with 30 or more tests for the same period, 14 reported a higher share; pooled, the state comes to 58.5%.
Which counties border Jasper County?
Jasper County borders 7 counties: Marshall County, Polk County, Poweshiek County, Marion County, Story County, Tama County and Mahaska County.
Products
Jasper County, Products
Testing a home in Jasper County
In Jasper County, 73.3% of 746 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 Jasper 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
View Plus radon and air quality monitor
- C-NRPP 2024/25: Approved
- Battery
- Wi-Fi, Bluetooth
- Screen, app
Method: Alpha spectrometry
Short-term kit
PicoCan short-term charcoal canister radon test
- Lab fee included
Method: Charcoal
In home: 48 to 96 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Jasper County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Jasper County
Explore
Jasper County, Bordering counties
Counties bordering Jasper County
Calculated by Radon411- Radon levels in Poweshiek CountyEPA zone 1
70.6%at or above 4 pCi/L
Median 7.2 pCi/L · 419 tests · 2.7 points below Jasper County
- Radon levels in Marshall CountyEPA zone 1
70.2%at or above 4 pCi/L
Median 8.2 pCi/L · 570 tests · 3.1 points below Jasper County
- Radon levels in Tama CountyEPA zone 1
67.9%at or above 4 pCi/L
Median 7.0 pCi/L · 333 tests · 5.4 points below Jasper County
- Radon levels in Marion CountyEPA zone 1
67.3%at or above 4 pCi/L
Median 6.0 pCi/L · 1,151 tests · 6.0 points below Jasper County
- Radon levels in Polk CountyEPA zone 1
64.4%at or above 4 pCi/L
Median 5.6 pCi/L · 10,945 tests · 8.9 points below Jasper County
- Radon levels in Mahaska CountyEPA zone 1
61.1%at or above 4 pCi/L
Median 5.2 pCi/L · 288 tests · 12.2 points below Jasper County
- Radon levels in Story CountyEPA zone 1
59.9%at or above 4 pCi/L
Median 5.0 pCi/L · 2,568 tests · 13.4 points below Jasper County
Jasper County, Cities and towns
Cities and towns in Jasper County
The Census Bureau estimates 38,153 residents in Jasper County for July 1, 2025, 332 more than in 2020 (+0.9%). That works out to 52 people per square mile of land. Its largest town, Newton, has 15,741 residents, 41.3% of the total. Reported testing is thin here: 746 tests over 2008 to 2017, or 19.6 for every 1,000 residents (2025 estimate), where Iowa as a whole comes to 29.4.
From Newton to Valeria, CDC publishes no figure by town: each reads Jasper County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Newton | 15,741 | Level | 41.3% |
| Mitchellvilleextends beyond Jasper County | 2,671 | +7.4% | Counted whole |
| Colfax | 2,303 | +2.1% | 6.0% |
| Monroe | 2,022 | +2.6% | 5.3% |
| Prairie City | 1,724 | +1.5% | 4.5% |
| Baxter | 984 | +1.4% | 2.6% |
| Sully | 891 | +1.0% | 2.3% |
| Kellogg | 599 | −0.3% | 1.6% |
| Lynnville | 383 | +0.3% | 1.0% |
| Mingo | 313 | +3.0% | 0.8% |
| Oakland Acres | 178 | +1.7% | 0.5% |
| Lambs Grove | 171 | −1.2% | 0.4% |
- Reasnor
- Valeria
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 Jasper County is counted whole, so it has no share.
Jasper County, Homes
Homes in Jasper County
Jasper County is a place of houses on their own lots: 78% of its 16,208 homes are detached single-family houses, against 72% across Iowa. Half of its homes were built before 1966, close to Iowa's 1971: 42% date from before 1960 and 12% from 2000 or later. 75% of occupied homes are lived in by their owner (Iowa: 72%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Jasper County | Iowa |
|---|---|---|
| Housing units | 16,208 | 1,427,175 |
| Detached houses | 78% | 72% |
| In buildings of 5 or more | 10% | 14% |
| Mobile homes | 3% | 3% |
| Built before 1960 | 42% | 39% |
| Built since 2000 | 12% | 21% |
| Middle year built | 1966 | 1971 |
| Owner-occupied | 75% | 72% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.