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 Hamblen County, Tennessee
EPA puts Hamblen County in Zone 1, its highest radon zone, and 37.0% of its 594 reported radon tests (2023) were 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
37.0%
12.1 pts above TN
- Hamblen
- 37.0%
- Tennessee
- 24.9%
594 tests, 2023
Median result
3.1pCi/L
Below action level
- Hamblen
- 3.1 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2023
Tests reported
594
Most tested in Tennessee
- Hamblen
- 594
Reported to CDC before any fix, 2023
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in Tennessee
3 of 15
Top quarter
- Hamblen
- 37.0%
- Blount
- 50.0%
By share, of 15 with 30+ tests
Read a result for Hamblen County
Starts at Hamblen County's median, 3.1 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 3.1 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. Hamblen County's median reported result, 2023.
The data
Hamblen County, At a glance
Hamblen County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Hamblen 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 Hamblen County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2022 | 31.7% |
| 2023 | 37.0% |
2023: 37.0%. Across these years the share ran from 31.7% to 37.0%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 594 tests reported to CDC for Hamblen County over 2023, 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: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).
Hamblen County, Compared
Hamblen County radon figures, compared
Calculated by Radon411In Hamblen County, about 4 in 10 reported tests in 2023 (220 of 594) were at or above EPA's action level. Against the national pool of 33.4%, the gap is 3.6 points higher. Across 70 Tennessee counties pooled together, 24.9% of tests reached that level, so Hamblen County runs 12.1 points above its state.
Of 2 neighbours with a figure, none reported a larger share at or above 4 pCi/L; the spread is 17.1% (Jefferson County) to 18.4% (Cocke County). By share, Hamblen County is 3rd of 15 Tennessee counties with 30 or more tests for the same period.
Half the tests came in under 3.1 pCi/L and half over it; the single highest reached 24.1 pCi/L. Below the action level, 164 tests (27.6%) came in under 2 pCi/L, against 49.4% statewide, and 210 tests (35.4%) fell between 2 and 4, against 25.7% statewide.
Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 37.0% share point the same way here. USGS geology rates 100% of the county's land high radon potential. CDC also counts 9 tests taken after mitigation in Hamblen County for the same period: tests in homes where a fix was already in.
The busiest year on file was 2023, with 594 tests reported; the quietest, 2022, had 123.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Hamblen County, Geology
The ground under Hamblen County
PredictedUSGS's geologic map puts all of Hamblen County's mapped land in one class: high radon potential. All of it lies in the area the map calls Ridge and Valley, to which USGS gives a radon index of 14, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Ridge and Valley | Paleozoic sandstone and cherty dolostone. | High | 14 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Hamblen County beside the ground around it
Hamblen County has more high-potential ground than Tennessee as a whole: 100% of its land against 47.2%. Of the 5 counties that border it, none has as large a share of high-potential ground; Grainger County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Hamblen County, Local resources
Radon testing and mitigation in Hamblen 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
Hamblen County, Questions
Questions about radon in Hamblen County
Are radon levels high in Hamblen County?
In 2023, 37.0% of the radon tests reported to CDC for Hamblen County, Tennessee were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.1 pCi/L. Of 15 Tennessee counties with 30 or more tests for the same period, 2 reported a higher share; pooled, the state comes to 24.9%.
Which counties border Hamblen County?
Hamblen County borders 5 counties: Jefferson County, Grainger County, Cocke County, Greene County and Hawkins County.
Products
Hamblen County, Products
Testing a home in Hamblen County
In Hamblen County, 37.0% of 594 tests reported to CDC in 2023 reached 4 pCi/L, against 24.9% pooled across Tennessee. In Zone 1 the year-round level in Hamblen 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
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
Short-term kitempowerDX
Standard Radon Test short-term mail-in radon test kit
- Lab fee included
Method: Passive sampler
In home: 48 to 96 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Hamblen County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Hamblen County
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Hamblen County, Bordering counties
Counties bordering Hamblen County
Calculated by Radon411- Radon levels in Grainger CountyEPA zone 1
100.0%at or above 4 pCi/L
Median 12.5 pCi/L · 4 tests · 63.0 points above Hamblen County
- Radon levels in Greene CountyEPA zone 1
47.1%at or above 4 pCi/L
Median 2.9 pCi/L · 17 tests · 10.1 points above Hamblen County
- Radon levels in Hawkins CountyEPA zone 1
33.3%at or above 4 pCi/L
Median 3.8 pCi/L · 3 tests · 3.7 points below Hamblen County
- Radon levels in Cocke CountyEPA zone 2
18.4%at or above 4 pCi/L
Median 1.4 pCi/L · 347 tests · 18.6 points below Hamblen County
- Radon levels in Jefferson CountyEPA zone 1
17.1%at or above 4 pCi/L
Median 2.6 pCi/L · 35 tests · 19.9 points below Hamblen County
Hamblen County, Cities and towns
Cities and towns in Hamblen County
Hamblen County is growing: the Census Bureau puts it at 68,843 residents on July 1, 2025, up 6.6% from 64,553 in 2020. That works out to 427 people per square mile of land. Morristown, the largest place on its list (33,517 residents in all), extends beyond Hamblen County, so no share of the total is worked out for it. Testing is reported here more often than across the state: CDC's 594 reported tests for 2023 come to 8.6 for every 1,000 residents (2025 estimate), against 0.3 for Tennessee.
From Morristown to White Pine, CDC publishes no figure by town: each reads Hamblen County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Morristownextends beyond Hamblen County | 33,517 | +9.8% | Counted whole |
| White Pineextends beyond Hamblen County | 2,619 | +2.8% | Counted whole |
2 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). A place that extends beyond Hamblen County is counted whole, so it has no share.
Hamblen County, Homes
Homes in Hamblen County
Of Hamblen County's 27,805 homes, 70% are detached houses, against 68% across Tennessee; 10% are mobile homes. Half of its homes were built before 1980, close to Tennessee's 1986: 16% date from before 1960 and 18% from 2000 or later. 68% 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 | Hamblen County | Tennessee |
|---|---|---|
| Housing units | 27,805 | 3,095,472 |
| Detached houses | 70% | 68% |
| In buildings of 5 or more | 8% | 14% |
| Mobile homes | 10% | 8% |
| Built before 1960 | 16% | 18% |
| Built since 2000 | 18% | 29% |
| Middle year built | 1980 | 1986 |
| Owner-occupied | 68% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.