Short-term kit
PicoCan short-term charcoal canister radon test
- Lab fee included
Method: Charcoal
In home: 48 to 96 hours
Locations and reports
Radon Levels in Polk County, Missouri
EPA puts Polk County in Zone 2, its middle radon zone, and only 3 radon tests from it are on file with CDC (2023). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
11.5%
19.1 pts below MO
- Polk
- 11.5%
- Missouri
- 30.6%
78 tests, 2008 to 2017
Median result
1.6pCi/L
Below action level
- Polk
- 1.6 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
78
45th of 72 by tests
- Polk
- 78
- St. Louis
- 17,747
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
EPA predicts 2 to 4 pCi/L indoors
Rank in Missouri
71 of 72
Lowest quarter
- Polk
- 11.5%
- Atchison
- 69.9%
By share, of 72 with 30+ tests
Read a result for Polk County
Starts at Polk County's median, 1.6 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 1.6 pCi/L
Below 2 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is below 2 pCi/L, the level at which EPA says a fix should be considered. Polk County's median reported result, 2008 to 2017.
The data
Polk County, At a glance
Polk County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Polk County is a
USGS geologic potential: Moderate across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Polk County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 0.0% |
| 2015 | 0.0% |
| 2016 | 20.0% |
| 2017 | 0.0% |
| 2019 | 100.0% |
| 2020 | 0.0% |
| 2021 | 50.0% |
| 2022 | 0.0% |
| 2023 | 66.7% |
2023: 66.7%. Across these years the share ran from 0.0% to 100.0%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 3 tests were reported to CDC for Polk County over 2023, and tests are often run on homes being sold or already suspected of a problem: so few describe neither the county nor this house.
Measured: CDC tracking data. Figure above: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).
Polk County, Compared
Polk County radon figures, compared
Calculated by Radon411Polk County reports fewer high tests than Missouri overall. 11.5% of its 78 tests over the 2008 to 2017 laboratory totals were at or above 4 pCi/L. That is 19.1 points below the 30.6% pooled from 115 Missouri counties.
The newest figure, in 2023, counts only 3 tests (66.7% at or above 4 pCi/L), too few to compare, so this reading uses the 78-test figure.
Ordered from highest share down, it comes 71st of 72 Missouri counties with 30 or more tests for the same period. Nationally, every county with a figure for the same period pools to 35.7%; Polk County sits 24.2 points below it.
Greene County, the one bordering county with a figure for the same period, reported 32.7%. Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 11.5% share point the same way here.
Half the tests came in under 1.6 pCi/L and half over it; the single highest reached 11.4 pCi/L. The rest split 66.7% under 2 pCi/L and 21.8% from 2 to 4 (Missouri: 41.2% and 28.1%).
The busiest year on file was 2014, with 8 tests reported; the quietest, 2019, had 1.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Polk County, Geology
The ground under Polk County
PredictedUSGS's geologic map puts all of Polk County's mapped land in one class: moderate radon potential. The map puts 64.1% of Polk County in the area it calls Salem Plateau and 35.9% in Springfield Plateau. USGS gives both a radon index of 11, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Salem Plateau | Ordovician dolomite, sandstone, limestone, and shale. | Moderate | 11 | 64.1% |
| Springfield Plateau | Mississippian limestone, shale, and sandstone. | Moderate | 11 | 35.9% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Polk County beside the ground around it
Across Missouri 8.2% of the land is rated high; none of Polk County's is. Of the 6 counties that border it, none has as large a share of moderate-potential ground; Cedar County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Polk County, Local resources
Radon testing and mitigation in Polk County
- Missouri Radon ProgramMissouri Radon Program, run by Missouri Department of Health and Senior Services, offers free or discounted test kits, and answers questions about testing and mitigation in Missouri.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Free radon test kits are available for Missouri residents (limit one per household).
- Compare kits
- Professionals in Missouri27 professionals are listed in Missouri.
What Missouri's program says
- Phone
- 573-751-6102
- radon@health.mo.gov
What it means
Polk County, Questions
Questions about radon in Polk County
Are radon levels high in Polk County?
In 2023, 66.7% of the radon tests reported to CDC for Polk County, Missouri were at or above 4 pCi/L, and the median reported pre-mitigation result was 5.4 pCi/L. Of 72 Missouri counties with 30 or more tests for the same period, 70 reported a higher share; pooled, the state comes to 30.6%.
Which counties border Polk County?
Polk County borders 6 counties: Dallas County, Hickory County, Cedar County, Dade County, St. Clair County and Greene County.
Products
Polk County, Products
Testing a home in Polk County
In Polk County, 11.5% of 78 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 30.6% pooled across Missouri. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Polk County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
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
Monitor
RadonScan-Plus USB-powered radon monitor with Wi-Fi
- C-NRPP 2024/25: Not included
- Plug-in
- Wi-Fi
- Alarm
- Screen, app
First reading: Within 5 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Polk County, Bordering counties
Counties bordering Polk County
Calculated by Radon411- Radon levels in Greene CountyEPA zone 2
32.7%at or above 4 pCi/L
Median 2.5 pCi/L · 1,470 tests · 21.2 points above Polk County
- Radon levels in Dallas CountyEPA zone 2
14.8%at or above 4 pCi/L
Median 1.4 pCi/L · 27 tests · 3.3 points above Polk County
- Radon levels in St. Clair CountyEPA zone 2
7.7%at or above 4 pCi/L
Median 1.5 pCi/L · 13 tests · 3.8 points below Polk County
- Radon levels in Cedar CountyEPA zone 2
5.0%at or above 4 pCi/L
Median 1.3 pCi/L · 20 tests · 6.5 points below Polk County
- Radon levels in Hickory CountyEPA zone 2
0.0%at or above 4 pCi/L
Median 2.0 pCi/L · 9 tests · 11.5 points below Polk County
- Radon levels in Dade CountyEPA zone 2
0.0%at or above 4 pCi/L
Median 1.3 pCi/L · 7 tests · 11.5 points below Polk County
Polk County, Cities and towns
Cities and towns in Polk County
Polk County is growing: the Census Bureau puts it at 33,604 residents on July 1, 2025, up 6.3% from 31,615 in 2020. That works out to 53 people per square mile of land. Its largest town, Bolivar, has 11,994 residents, 35.7% of the total. Together its 8 incorporated places hold 44.1% of those residents; the other 55.9% live outside any of them. Reported testing is thin here: 78 tests over 2008 to 2017, or 2.3 for every 1,000 residents (2025 estimate), where Missouri as a whole comes to 9.3.
From Bolivar to Aldrich, CDC publishes no figure by town: each reads Polk County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Bolivar | 11,994 | +11.0% | 35.7% |
| Humansville | 942 | +3.2% | 2.8% |
| Pleasant Hope | 694 | +3.4% | 2.1% |
| Fair Play | 452 | +3.9% | 1.3% |
| Morrisville | 398 | +3.9% | 1.2% |
| Halfway | 152 | +3.4% | 0.5% |
| Flemington | 115 | +4.5% | 0.3% |
| Aldrich | 69 | +4.5% | 0.2% |
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).
Polk County, Homes
Homes in Polk County
Polk County is a place of houses on their own lots: 76% of its 13,434 homes are detached single-family houses, against 70% across Missouri. Much of Polk County is recent building: 30% of its homes have gone up since 2000 and the middle year built is 1987, against 1978 for Missouri. 71% of occupied homes are lived in by their owner (Missouri: 68%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Polk County | Missouri |
|---|---|---|
| Housing units | 13,434 | 2,809,501 |
| Detached houses | 76% | 70% |
| In buildings of 5 or more | 4% | 13% |
| Mobile homes | 10% | 5% |
| Built before 1960 | 17% | 28% |
| Built since 2000 | 30% | 21% |
| Middle year built | 1987 | 1978 |
| Owner-occupied | 71% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.