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 Swain County, North Carolina
EPA puts Swain County in Zone 2, its middle radon zone, and only 2 radon tests from it are on file with CDC (2022). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
42.9%
19.7 pts above NC
- Swain
- 42.9%
- NC
- 23.2%
126 tests, 2007 to 2016
Median result
3.3pCi/L
Below action level
- Swain
- 3.3 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2007 to 2016
Tests reported
126
54th of 73 by tests
- Swain
- 126
- Wake
- 9,664
Reported to CDC before any fix, 2007 to 2016
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 NC
4 of 73
Top quarter
- Swain
- 42.9%
- Transylvania
- 48.1%
By share, of 73 with 30+ tests
Read a result for Swain County
Starts at Swain County's median, 3.3 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 3.3 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. Swain County's median reported result, 2007 to 2016.
The data
Swain County, At a glance
Swain County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Swain 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 Swain County, 2022
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 13.9% |
| 2020 | 36.7% |
| 2021 | 35.0% |
| 2022 | 0.0% |
2022: 0.0%. Across these years the share ran from 0.0% to 36.7%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 2 tests were reported to CDC for Swain County over 2022, 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: 2022. Measured data period: 2005 to 2022 (every CDC figure on file).
Swain County, Compared
Swain County radon figures, compared
Calculated by Radon411In Swain County, about 4 in 10 reported tests over the 2007 to 2016 laboratory totals (54 of 126) were at or above EPA's action level. Against the national pool of 35.8%, the gap is 7.1 points higher. Across 99 North Carolina counties pooled together, 23.2% of tests reached that level, so Swain County runs 19.7 points above its state.
The newest figure, in 2022, counts only 2 tests (0.0% at or above 4 pCi/L), too few to compare, so this reading uses the 126-test figure.
Of 6 neighbours with a figure, 2 reported a larger share at or above 4 pCi/L and 4 a smaller one; the spread is 17.6% (Macon County) to 52.3% (Sevier County, TN). By share, Swain County is 4th of 73 North Carolina counties with 30 or more tests for the same period.
Half the tests came in under 3.3 pCi/L and half over it; the single highest reached 86.9 pCi/L. Below the action level, 42 tests (33.3%) came in under 2 pCi/L, against 55.2% statewide, and 30 tests (23.8%) fell between 2 and 4, against 21.6% statewide.
Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 42.9% share point the same way here. USGS geology rates 100% of the county's land moderate radon potential. CDC also counts 6 tests taken after mitigation in Swain County for the same period: tests in homes where a fix was already in.
The busiest year on file was 2014, with 36 tests reported; the quietest, 2022, had 2.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Swain County, Geology
The ground under Swain County
PredictedUSGS's geologic map puts all of Swain County's mapped land in one class: moderate radon potential. All of it lies in the area the map calls Blue Ridge, to which USGS gives a radon index of 10, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Blue Ridge | Granite, pegmatite, monazite, schist, and gneiss. | Moderate | 10 | 99.8% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Swain County beside the ground around it
Across North Carolina 1.3% of the land is rated high; none of Swain County's is. Of the 6 counties that border it, 2 have more high-potential ground, Blount County, TN the most at 63.2%.
The map rates the ground, not the air in any home.
Local help
Swain County, Local resources
Radon testing and mitigation in Swain County
- North Carolina Radon ProgramNorth Carolina Radon Program, run by NCDHHS, answers questions about testing, mitigation and the rules in North Carolina.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsAsk the program whether it has free or discounted kits, or compare kits you can buy.
- Compare kits
- Professionals in North Carolina2 professionals are listed in North Carolina.
What North Carolina's program says
- Licensing of radon professionals
The North Carolina Radon Program is presently developing a Radon Proficiency Program as directed by Session Law 2023-91 House Bill 782 .
What it means
Swain County, Questions
Questions about radon in Swain County
Are radon levels high in Swain County?
In 2022, 0.0% of the radon tests reported to CDC for Swain County, North Carolina were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.6 pCi/L. Of 73 North Carolina counties with 30 or more tests for the same period, 3 reported a higher share; pooled, the state comes to 23.2%.
Which counties border Swain County?
Swain County borders 6 counties: Graham County, NC, Blount County, TN, Sevier County, TN, Macon County, NC, Jackson County, NC and Haywood County, NC.
Products
Swain County, Products
Testing a home in Swain County
In Swain County, 42.9% of 126 tests reported to CDC over the 2007 to 2016 laboratory totals reached 4 pCi/L, against 23.2% pooled across North Carolina. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Swain 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
Swain County, Bordering counties
Counties bordering Swain County
Calculated by Radon411- Radon levels in Sevier County, TNEPA zone 2
52.3%at or above 4 pCi/L
Median 4.3 pCi/L · 302 tests · 9.4 points above Swain County
- Radon levels in Blount County, TNEPA zone 1
44.8%at or above 4 pCi/L
Median 3.6 pCi/L · 703 tests · 1.9 points above Swain County
- Radon levels in Graham County, NCEPA zone 2
41.2%at or above 4 pCi/L
Median 2.9 pCi/L · 68 tests · 1.7 points below Swain County
- Radon levels in Haywood County, NCEPA zone 2
30.2%at or above 4 pCi/L
Median 2.2 pCi/L · 1,951 tests · 12.7 points below Swain County
- Radon levels in Jackson County, NCEPA zone 2
26.8%at or above 4 pCi/L
Median 2.1 pCi/L · 1,024 tests · 16.1 points below Swain County
- Radon levels in Macon County, NCEPA zone 2
17.6%at or above 4 pCi/L
Median 1.3 pCi/L · 1,313 tests · 25.3 points below Swain County
Swain County, Cities and towns
Cities and towns in Swain County
About 14,024 people live in Swain County by the Census Bureau's estimate for July 1, 2025, 83 fewer than in 2020 (−0.6%). That works out to 27 people per square mile of land. Bryson City, its one incorporated place, has 1,525 residents, 10.9% of the total. CDC's 126 reported tests for 2007 to 2016 work out to 9.0 per 1,000 residents (2025 estimate), close to North Carolina's 6.3.
Bryson City is the one incorporated place here; CDC publishes no figure by town, so it reads Swain County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Bryson City | 1,525 | −1.4% | 10.9% |
One incorporated place, 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).
Swain County, Homes
Homes in Swain County
Of Swain County's 8,529 homes, 67% are detached houses, against 65% across North Carolina; 26% are mobile homes. Half of its homes were built before 1989, close to North Carolina's 1990: 12% date from before 1960 and 27% from 2000 or later. 73% of occupied homes are lived in by their owner (North Carolina: 66%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Swain County | North Carolina |
|---|---|---|
| Housing units | 8,529 | 4,815,195 |
| Detached houses | 67% | 65% |
| In buildings of 5 or more | 2% | 14% |
| Mobile homes | 26% | 11% |
| Built before 1960 | 12% | 14% |
| Built since 2000 | 27% | 33% |
| Middle year built | 1989 | 1990 |
| Owner-occupied | 73% | 66% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.