Short-term kitFirst Alert
RD1 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 2 to 4 days
Locations and reports
Radon Levels in Sevier County, Tennessee
EPA puts Sevier County in Zone 2, its middle radon zone, and only 18 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
53.0%
19.7 pts above TN
- Sevier
- 53.0%
- Tennessee
- 33.3%
328 tests, 2008 to 2017
Median result
4.4pCi/L
Action level reached
- Sevier
- 4.4 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
328
19th of 80 by tests
- Sevier
- 328
- 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
4 of 80
Top quarter
- Sevier
- 53.0%
- Jefferson
- 56.8%
By share, of 80 with 30+ tests
Read a result for Sevier County
Starts at Sevier County's median, 4.4 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 4.4 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. Sevier County's median reported result, 2008 to 2017.
The data
Sevier County, At a glance
Sevier County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Sevier County is a
USGS geologic potential: Moderate across 62% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Sevier County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2022 | 21.7% |
| 2023 | 33.3% |
2023: 33.3%. Across these years the share ran from 21.7% to 33.3%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 18 tests were reported to CDC for Sevier 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).
Sevier County, Compared
Sevier County radon figures, compared
Calculated by Radon411More than half: 53.0% of the 328 radon tests reported to CDC for Sevier County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 4th of 80 Tennessee counties with 30 or more tests for the same period. That is 19.7 points above the 33.3% pooled from 95 Tennessee counties.
The newest figure, in 2023, counts only 18 tests (33.3% at or above 4 pCi/L), too few to compare, so this reading uses the 328-test figure.
The median result, 4.4 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 77.6 pCi/L. The rest split 22.3% under 2 pCi/L and 24.7% from 2 to 4 (Tennessee: 42.4% and 24.3%). The reported tests do not follow EPA's Zone 2 label for Sevier County (predicted average between 2 and 4 pCi/L): 53.0% of them reached 4 pCi/L, fewer than that label suggests.
1 of its 6 bordering counties with figures ran higher, led by Jefferson County at 56.8%; Haywood County, NC reported 30.6%. Statewide for the same period, Jefferson County reported the highest share (56.8%) and Chester County the lowest (0.0%).
The busiest year on file was 2022, with 180 tests reported; the quietest, 2023, had 18.
Nationally, every county with a figure for the same period pools to 35.7%; Sevier County sits 17.3 points above it. CDC also counts 32 tests taken after mitigation in Sevier 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.
Sevier County, Geology
The ground under Sevier County
PredictedUSGS's geologic map splits Sevier County: 61.5% of its land is moderate radon potential and 38.5% high. The map puts 61.2% of Sevier County in the area it calls Unaka Mountains and 38.5% in Ridge and Valley. USGS gives the first a radon index of 11, in the moderate band (9 to 11), and the second 14, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Unaka Mountains | Precambrian and Paleozoic siltstone, sandstone, conglomerate, quartzite, phyllite, gneiss, granite, and metamorphosed volcanic rock. | Moderate | 11 | 61.2% |
| Ridge and Valley | Paleozoic sandstone and cherty dolostone. | High | 14 | 38.5% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Sevier County beside the ground around it
On high-potential ground Sevier County is close to Tennessee as a whole: 38.5% of its land against 47.2%. Of the 6 counties that border it, 4 have more high-potential ground, Jefferson County the most at 100%.
The map rates the ground, not the air in any home.
Local help
Sevier County, Local resources
Radon testing and mitigation in Sevier 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
Sevier County, Questions
Questions about radon in Sevier County
Are radon levels high in Sevier County?
In 2023, 33.3% of the radon tests reported to CDC for Sevier County, Tennessee were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.3 pCi/L. Of 80 Tennessee counties with 30 or more tests for the same period, 3 reported a higher share; pooled, the state comes to 33.3%.
Which counties border Sevier County?
Sevier County borders 6 counties: Jefferson County, TN, Swain County, NC, Blount County, TN, Knox County, TN, Cocke County, TN and Haywood County, NC.
Products
Sevier County, Products
Testing a home in Sevier County
In Sevier County, 53.0% of 328 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 Sevier 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
View Plus radon and air quality monitor
- C-NRPP 2024/25: Approved
- Battery
- Wi-Fi, Bluetooth
- Screen, app
Method: Alpha spectrometry
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Sevier County, Bordering counties
Counties bordering Sevier County
Calculated by Radon411- Radon levels in Jefferson County, TNEPA zone 1
56.8%at or above 4 pCi/L
Median 4.7 pCi/L · 146 tests · 3.8 points above Sevier County
- Radon levels in Cocke County, TNEPA zone 2
46.4%at or above 4 pCi/L
Median 3.8 pCi/L · 56 tests · 6.6 points below Sevier County
- Radon levels in Swain County, NCEPA zone 2
44.0%at or above 4 pCi/L
Median 3.4 pCi/L · 116 tests · 9.0 points below Sevier County
- Radon levels in Blount County, TNEPA zone 1
42.8%at or above 4 pCi/L
Median 3.4 pCi/L · 745 tests · 10.2 points below Sevier County
- Radon levels in Knox County, TNEPA zone 1
33.6%at or above 4 pCi/L
Median 2.5 pCi/L · 2,452 tests · 19.4 points below Sevier County
- Radon levels in Haywood County, NCEPA zone 2
30.6%at or above 4 pCi/L
Median 2.2 pCi/L · 1,872 tests · 22.4 points below Sevier County
Sevier County, Cities and towns
Cities and towns in Sevier County
The Census Bureau estimates 101,342 residents in Sevier County for July 1, 2025, 2,494 more than in 2020 (+2.5%). That works out to 171 people per square mile of land. No town dominates: Sevierville, the largest, has 19,010 residents, 18.8% of the total. Together its 4 incorporated places hold 29.4% of those residents; the other 70.6% live outside any of them. CDC's 328 reported tests for 2008 to 2017 work out to 3.2 per 1,000 residents (2025 estimate), close to Tennessee's 4.2.
From Sevierville to Pittman Center, CDC publishes no figure by town: each reads Sevier County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Sevierville | 19,010 | +2.9% | 18.8% |
| Pigeon Forge | 6,598 | +3.0% | 6.5% |
| Gatlinburg | 3,715 | +4.5% | 3.7% |
| Pittman Center | 462 | +1.5% | 0.5% |
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).
Sevier County, Homes
Homes in Sevier County
Of Sevier County's 57,809 homes, 69% are detached houses, against 68% across Tennessee; 12% are in buildings of five or more homes. Much of Sevier County is recent building: 39% of its homes have gone up since 2000 and the middle year built is 1995, against 1986 for Tennessee. 72% 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 | Sevier County | Tennessee |
|---|---|---|
| Housing units | 57,809 | 3,095,472 |
| Detached houses | 69% | 68% |
| In buildings of 5 or more | 12% | 14% |
| Mobile homes | 12% | 8% |
| Built before 1960 | 7% | 18% |
| Built since 2000 | 39% | 29% |
| Middle year built | 1995 | 1986 |
| Owner-occupied | 72% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.