Short-term kit
RA400 short-term liquid scintillation radon test kit, lab fee included
- Lab fee included
Method: Liquid scintillation
In home: 48 to 96 hours
Locations and reports
Radon Levels in Putnam County, Tennessee
EPA puts Putnam County in Zone 2, its middle radon zone, and only 21 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
36.0%
2.7 pts above TN
- Putnam
- 36.0%
- Tennessee
- 33.3%
336 tests, 2008 to 2017
Median result
2.6pCi/L
Below action level
- Putnam
- 2.6 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
336
18th of 80 by tests
- Putnam
- 336
- Davidson
- 5,592
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 Tennessee
28 of 80
Middle half
- Putnam
- 36.0%
- Jefferson
- 56.8%
By share, of 80 with 30+ tests
Read a result for Putnam County
Starts at Putnam County's median, 2.6 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.6 pCi/L
Between 2 and 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is between 2 and 4 pCi/L. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Putnam County's median reported result, 2008 to 2017.
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 78% 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 |
|---|---|
| 2022 | 55.0% |
| 2023 | 23.8% |
2023: 23.8%. Across these years the share ran from 23.8% to 55.0%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 21 tests were 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 Radon411In Putnam County, about 4 in 10 reported tests over the 2008 to 2017 laboratory totals (121 of 336) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 0.3 points higher. Across 95 Tennessee counties pooled together, 33.3% of tests reached that level, so Putnam County runs 2.7 points above its state.
The newest figure, in 2023, counts only 21 tests (23.8% at or above 4 pCi/L), too few to compare, so this reading uses the 336-test figure.
Of 7 neighbours with a figure, 4 reported a larger share at or above 4 pCi/L and 3 a smaller one; the spread is 8.7% (Cumberland County) to 49.0% (White County). By share, Putnam County is 28th of 80 Tennessee counties with 30 or more tests for the same period.
Half the tests came in under 2.6 pCi/L and half over it; the single highest reached 100.0 pCi/L. Below the action level, 139 tests (41.4%) came in under 2 pCi/L, against 42.4% statewide, and 76 tests (22.6%) fell between 2 and 4, against 24.3% statewide.
Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 36.0% share point the same way here. USGS geology rates 78% of the county's land moderate radon potential. CDC also counts 10 tests taken after mitigation in Putnam County for the same period: tests in homes where a fix was already in.
The busiest year on file was 2022, with 60 tests reported; the quietest, 2023, had 21.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Putnam County, Geology
The ground under Putnam County
PredictedMost of the ground under Putnam County is one class on USGS's geologic map: 77.5% of its land is moderate radon potential, with 9.4% high and 13.0% low. The map puts 77.5% of Putnam County in the area it calls Highland Rim and 13.0% in Appalachian Plateau, with one smaller area beside them. USGS gives the first a radon index of 11, in the moderate band (9 to 11), and the second 8, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Highland Rim | Paleozoic sedimentary rocks (limestone, shale, chert, and dolostone). | Moderate | 11 | 77.5% |
| Appalachian Plateau | Sandstone and shale. | Low | 8 | 13.0% |
| Nashville Basin | Mississippian Limestone. | High | 14 | 9.4% |
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
Tennessee as a whole has more high-potential ground than Putnam County: 47.2% of its land, against 9.4% here. Of the 7 counties that border it, 3 have more high-potential ground, Smith County the most at 100%.
The map rates the ground, not the air in any home.
Local help
Putnam County, Local resources
Radon testing and mitigation in Putnam County
- Tennessee Radon ProgramTennessee Radon Program, run by Department of Environment & Conservation, offers free or discounted test kits, and answers questions about testing and mitigation in Tennessee.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
The Tennessee Radon Program provides free radon test kits and information assistance to residents, while also providing training opportunities to radon professionals across the state.
- Compare kits
- Professionals in Tennessee1 professional is listed in Tennessee.
What Tennessee's program says
- Phone
- 1-800-232-1139
- TDEC.Radon@tn.gov
What it means
Putnam County, Questions
Questions about radon in Putnam County
Are radon levels high in Putnam County?
In 2023, 23.8% of the radon tests reported to CDC for Putnam County, Tennessee were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.5 pCi/L. Of 80 Tennessee counties with 30 or more tests for the same period, 27 reported a higher share; pooled, the state comes to 33.3%.
Which counties border Putnam County?
Putnam County borders 7 counties: White County, Overton County, Jackson County, DeKalb County, Cumberland County, Smith County and Fentress County.
Products
Putnam County, Products
Testing a home in Putnam County
In Putnam County, 36.0% of 336 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 33.3% pooled across Tennessee. 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
RL416 long-term radon test kit, lab fee included
- Lab fee included
Method: Alpha track
In home: 90 days to 12 months
Monitor
Hello Radon C battery radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Screen
Method: Alpha spectrometry
First reading: Within 24 hours
- 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 White CountyEPA zone 2
49.0%at or above 4 pCi/L
Median 3.9 pCi/L · 147 tests · 13.0 points above Putnam County
- Radon levels in Jackson CountyEPA zone 1
46.9%at or above 4 pCi/L
Median 3.9 pCi/L · 49 tests · 10.9 points above Putnam County
- Radon levels in Smith CountyEPA zone 1
45.5%at or above 4 pCi/L
Median 3.1 pCi/L · 55 tests · 9.5 points above Putnam County
- Radon levels in Overton CountyEPA zone 2
40.6%at or above 4 pCi/L
Median 2.8 pCi/L · 128 tests · 4.6 points above Putnam County
- Radon levels in DeKalb CountyEPA zone 2
30.5%at or above 4 pCi/L
Median 3.1 pCi/L · 59 tests · 5.5 points below Putnam County
- Radon levels in Fentress CountyEPA zone 2
9.1%at or above 4 pCi/L
Median 1.3 pCi/L · 33 tests · 26.9 points below Putnam County
- Radon levels in Cumberland CountyEPA zone 3
8.7%at or above 4 pCi/L
Median 1.3 pCi/L · 172 tests · 27.3 points below Putnam County
Putnam County, Cities and towns
Cities and towns in Putnam County
Putnam County is growing: the Census Bureau puts it at 86,612 residents on July 1, 2025, up 8.1% from 80,101 in 2020. That works out to 216 people per square mile of land. Its largest town, Cookeville, has 38,212 residents, 44.1% of the total. Together its 4 incorporated places hold 54.6% of those residents; the other 45.4% live outside any of them. CDC's 336 reported tests for 2008 to 2017 work out to 3.9 per 1,000 residents (2025 estimate), close to Tennessee's 4.2.
From Cookeville to Baxter, CDC publishes no figure by town: each reads Putnam County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Cookeville | 38,212 | +9.3% | 44.1% |
| Algood | 4,165 | +4.4% | 4.8% |
| Monterey | 2,827 | +2.9% | 3.3% |
| Baxter | 2,128 | +34.7% | 2.5% |
4 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
Of Putnam County's 35,991 homes, 65% are detached houses, against 68% across Tennessee; 14% are in buildings of five or more homes. Half of its homes were built before 1990, close to Tennessee's 1986: 11% date from before 1960 and 32% from 2000 or later. 61% of occupied homes are lived in by their owner (Tennessee: 67%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Putnam County | Tennessee |
|---|---|---|
| Housing units | 35,991 | 3,095,472 |
| Detached houses | 65% | 68% |
| In buildings of 5 or more | 14% | 14% |
| Mobile homes | 9% | 8% |
| Built before 1960 | 11% | 18% |
| Built since 2000 | 32% | 29% |
| Middle year built | 1990 | 1986 |
| Owner-occupied | 61% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.