Short-term kit
RA100 short-term liquid scintillation radon test kit
- Lab fee extra
Method: Liquid scintillation
In home: 48 to 96 hours
Locations and reports
Radon Levels in Putnam County, Missouri
EPA puts Putnam County in Zone 2, its middle radon zone, and only 1 radon test from it is on file with CDC (2023). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Highest bordering
45.3%
Appanoose County
- Appanoose
- 45.3%
- Adair
- 27.2%
3 of 6 neighbours have 30+ tests, 2008 to 2017
Nearest county
27.2%
Adair County, 30 miles
- Adair
- 27.2%
- Missouri
- 30.6%
Share at 4+ pCi/L, 92 tests, 2008 to 2017
Ground above low
100.0%
5.8 pts above Missouri
- Putnam
- 100.0%
- Missouri
- 94.2%
Share of land USGS rates moderate or high potential
Tests reported
14
Too few for a share
- Putnam
- 14
- Needed
- 30
2005 to 2014, laboratory
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
EPA predicts 2 to 4 pCi/L indoors
Read a result for Putnam County
Starts at EPA's action level
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 4.0 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.
The data
Putnam County, At a glance
Putnam County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Putnam 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 Putnam County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 0.0% |
| 2018 | 0.0% |
| 2022 | 100.0% |
| 2023 | 0.0% |
2023: 0.0%. 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 1 test was reported to CDC for Putnam 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).
Putnam County, Compared
Putnam County radon figures, compared
Calculated by Radon411CDC's largest figure for Putnam County rests on 14 tests over the 2005 to 2014 laboratory totals, 3 of them at or above 4 pCi/L, so each test moves its share by 7.1 points and no rank or comparison is drawn from it. Results reached as high as 7.4 pCi/L, with a middle value of 1.3 pCi/L.
Of the counties bordering it, 3 have a figure over the 2008 to 2017 laboratory totals: Appanoose County, IA reported the largest share at or above 4 pCi/L, 45.3%, and Adair County the smallest, 27.2%, with Wayne County, IA at 34.8% between. Farther out, Linn County (42 miles away) at 18.9%, Macon County (51 miles away) at 19.4% and Livingston County (56 miles away) at 22.4% have figures too. Pooled across 115 Missouri counties, 30.6% of reported tests reached that level; across every county in the country with a figure, 35.7%.
Statewide for the same period, Atchison County reported the highest share (69.9%) and Vernon County the lowest (8.8%). EPA's 1993 map puts Putnam County in Zone 2, its middle label: a predicted county average between 2 and 4 pCi/L. USGS geology rates 100% of the county's land moderate radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Putnam County, Geology
The ground under Putnam County
PredictedUSGS's geologic map puts all of Putnam County's mapped land in one class: moderate radon potential. All of it lies in the area the map calls Dissected Till Plains, to which USGS gives 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 |
|---|---|---|---|---|
| Dissected Till Plains | Till-covered Pennsylvanian sandstone, shale, and limestone. | Moderate | 11 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Putnam County beside the ground around it
Across Missouri 8.2% of the land is rated high; none of Putnam County's is. Of the 6 counties that border it, 2 have more high-potential ground, Wayne County, IA the most at 77.1%.
The map rates the ground, not the air in any home.
Local help
Putnam County, Local resources
Radon testing and mitigation in Putnam 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
Putnam County, Questions
Questions about radon in Putnam County
Are radon levels high in Putnam County?
In 2023, 0.0% of the radon tests reported to CDC for Putnam County, Missouri were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.9 pCi/L. Of the counties bordering it, 3 have a figure over the 2008 to 2017 laboratory totals: Appanoose County, IA reported the largest share at or above 4 pCi/L, 45.3%, and Adair County the smallest, 27.2%, with Wayne County, IA at 34.8% between.
Which counties border Putnam County?
Putnam County borders 6 counties: Appanoose County, IA, Sullivan County, MO, Wayne County, IA, Schuyler County, MO, Mercer County, MO and Adair County, MO.
Products
Putnam County, Products
Testing a home in Putnam County
No CDC figure names Putnam County; the nearest county with one, Adair County (30 miles away), reported 27.2% of its tests at or above 4 pCi/L over the 2008 to 2017 laboratory totals, the only reading nearby until a test of this home. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Putnam County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
Monitor
lüft plug-in radon and indoor air quality monitor
- C-NRPP 2024/25: Approved
- Plug-in
- Wi-Fi, Bluetooth
- App only
First reading: Within 90 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Putnam County, Bordering counties
Counties bordering Putnam County
Calculated by Radon411- Radon levels in Appanoose County, IAEPA zone 1
45.3%at or above 4 pCi/L
Median 3.7 pCi/L · 117 tests
- Radon levels in Wayne County, IAEPA zone 1
34.8%at or above 4 pCi/L
Median 3.0 pCi/L · 46 tests
- Radon levels in Sullivan County, MOEPA zone 2
33.3%at or above 4 pCi/L
Median 1.4 pCi/L · 6 tests
- Radon levels in Mercer County, MOEPA zone 2
27.3%at or above 4 pCi/L
Median 1.7 pCi/L · 11 tests
- Radon levels in Adair County, MOEPA zone 2
27.2%at or above 4 pCi/L
Median 1.8 pCi/L · 92 tests
- Radon levels in Schuyler County, MOEPA zone 2
9.1%at or above 4 pCi/L
Median 1.0 pCi/L · 11 tests
Putnam County, Cities and towns
Cities and towns in Putnam County
About 4,546 people live in Putnam County by the Census Bureau's estimate for July 1, 2025, 140 fewer than in 2020 (−3.0%). Spread over its land, that is 8.8 people to the square mile. Its largest town, Unionville, has 1,663 residents, 36.6% of the total. Together its 5 incorporated places hold 41.2% of those residents; the other 58.8% live outside any of them. Reported testing is thin here: 14 tests over 2005 to 2014, or 3.1 for every 1,000 residents (2025 estimate), where Missouri as a whole comes to 6.8.
From Unionville to Powersville, CDC publishes no figure by town: each reads Putnam County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Unionville | 1,663 | −3.4% | 36.6% |
| Worthington | 57 | −3.4% | 1.3% |
| Lucerne | 55 | −1.8% | 1.2% |
| Livonia | 54 | −1.8% | 1.2% |
| Powersville | 42 | Level | 0.9% |
5 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).
Putnam County, Homes
Homes in Putnam County
Putnam County is a place of houses on their own lots: 81% of its 2,845 homes are detached single-family houses, against 70% across Missouri. Half of its homes were built before 1977, close to Missouri's 1978: 27% date from before 1960 and 22% from 2000 or later. Owners live in 81% of the occupied homes (Missouri: 68%), so for most households a test and a fix are their own to order.
| Homes | Putnam County | Missouri |
|---|---|---|
| Housing units | 2,845 | 2,809,501 |
| Detached houses | 81% | 70% |
| In buildings of 5 or more | under 1% | 13% |
| Mobile homes | 11% | 5% |
| Built before 1960 | 27% | 28% |
| Built since 2000 | 22% | 21% |
| Middle year built | 1977 | 1978 |
| Owner-occupied | 81% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.