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 Polk County, North Carolina
EPA puts Polk County in Zone 2, its middle radon zone, and only 1 radon test from it is 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
31.2%
8.0 pts above NC
- Polk
- 31.2%
- NC
- 23.2%
616 tests, 2007 to 2016
Median result
2.4pCi/L
Below action level
- Polk
- 2.4 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2007 to 2016
Tests reported
616
28th of 73 by tests
- Polk
- 616
- 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
19 of 73
Middle half
- Polk
- 31.2%
- Transylvania
- 48.1%
By share, of 73 with 30+ tests
Read a result for Polk County
Starts at Polk County's median, 2.4 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.4 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. Polk County's median reported result, 2007 to 2016.
The data
Polk County, At a glance
Polk County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Polk 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 Polk County, 2022
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 33.7% |
| 2020 | 25.6% |
| 2021 | 26.5% |
| 2022 | 0.0% |
2022: 0.0%. Across these years the share ran from 0.0% to 33.7%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 1 test was reported to CDC for Polk 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).
Polk County, Compared
Polk County radon figures, compared
Calculated by Radon411In Polk County, about 3 in 10 reported tests over the 2007 to 2016 laboratory totals (192 of 616) were at or above EPA's action level. Against the national pool of 35.8%, the gap is 4.6 points lower. Across 99 North Carolina counties pooled together, 23.2% of tests reached that level, so Polk County runs 8.0 points above its state.
The newest figure, in 2022, counts only 1 test (0.0% at or above 4 pCi/L), too few to compare, so this reading uses the 616-test figure.
Of 4 neighbours with a figure, 1 reported a larger share at or above 4 pCi/L and 3 a smaller one; the spread is 19.9% (Spartanburg County, SC) to 42.6% (Henderson County). By share, Polk County is 19th of 73 North Carolina counties with 30 or more tests for the same period.
Year by year, 2014 opened at 33.7% and 2021 closed at 26.5% (down 7.2 points), with 2014 the high at 33.7%. Half the tests came in under 2.4 pCi/L and half over it; the single highest reached 21.5 pCi/L. Below the action level, 257 tests (41.7%) came in under 2 pCi/L, against 55.2% statewide, and 167 tests (27.1%) 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 31.2% share point the same way here. USGS geology rates 100% of the county's land moderate radon potential. CDC also counts 39 tests taken after mitigation in Polk County for the same period: tests in homes where a fix was already in.
The busiest year on file was 2020, with 129 tests reported; the quietest, 2022, had 1.
Polk CountyNorth Carolina, pooled
26.5% % of tests14.9% % of tests
| Year | Tests | Polk County, at or above 4 pCi/L | North Carolina, pooled |
|---|---|---|---|
| 2014 | 98 | 33.7% | 21.9% |
| 2020 | 129 | 25.6% | 21.1% |
| 2021 | 49 | 26.5% | 14.9% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Polk County, Geology
The ground under Polk County
PredictedUSGS's geologic map puts all of Polk County's mapped land in one class: moderate radon potential. All of it lies in the area the map calls Inner Piedmont Belt, 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 |
|---|---|---|---|---|
| Inner Piedmont Belt | Proterozoic through Cambrian biotite gneiss and schist, and mica schist. | 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.
Polk County beside the ground around it
Across North Carolina 1.3% of the land is rated high; none of Polk County's is. Of the 4 counties that border it, 2 have more high-potential ground, Henderson County the most at 52.6%.
The map rates the ground, not the air in any home.
Local help
Polk County, Local resources
Radon testing and mitigation in Polk 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
Polk County, Questions
Questions about radon in Polk County
Are radon levels high in Polk County?
In 2022, 0.0% of the radon tests reported to CDC for Polk County, North Carolina were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.0 pCi/L. Of 73 North Carolina counties with 30 or more tests for the same period, 18 reported a higher share; pooled, the state comes to 23.2%.
Which counties border Polk County?
Polk County borders 4 counties: Rutherford County, NC, Henderson County, NC, Spartanburg County, SC and Greenville County, SC.
Products
Polk County, Products
Testing a home in Polk County
In Polk County, 31.2% of 616 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 Polk 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
MonitorAEGTEST
HOUND-3699 radon monitor with a 2.1-inch touchscreen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
First reading: Within 1 hour
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Polk County, Bordering counties
Counties bordering Polk County
Calculated by Radon411- Radon levels in Henderson County, NCEPA zone 1
42.6%at or above 4 pCi/L
Median 3.3 pCi/L · 4,126 tests · 11.4 points above Polk County
- Radon levels in Rutherford County, NCEPA zone 2
26.6%at or above 4 pCi/L
Median 2.4 pCi/L · 481 tests · 4.6 points below Polk County
- Radon levels in Spartanburg County, SCEPA zone 2
19.9%at or above 4 pCi/L
Median 1.8 pCi/L · 3,104 tests · 11.3 points below Polk County
- Radon levels in Greenville County, SCEPA zone 1
19.9%at or above 4 pCi/L
Median 1.8 pCi/L · 11,402 tests · 11.3 points below Polk County
Polk County, Cities and towns
Cities and towns in Polk County
Polk County is growing: the Census Bureau puts it at 20,533 residents on July 1, 2025, up 6.0% from 19,378 in 2020. That works out to 86 people per square mile of land. No town dominates: Tryon, the largest, has 1,634 residents, 8.0% of the total. Testing is reported here more often than across the state: CDC's 616 reported tests for 2007 to 2016 come to 30.0 for every 1,000 residents (2025 estimate), against 6.3 for North Carolina.
From Tryon to Saluda, CDC publishes no figure by town: each reads Polk County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Tryon | 1,634 | +5.4% | 8.0% |
| Columbus | 1,042 | +5.1% | 5.1% |
| Saludaextends beyond Polk County | 671 | +6.3% | Counted whole |
3 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 Polk County is counted whole, so it has no share.
Polk County, Homes
Homes in Polk County
Polk County is a place of houses on their own lots: 79% of its 10,949 homes are detached single-family houses, against 65% across North Carolina. The homes are older than North Carolina's as a whole: half were built before 1982 (1990 for North Carolina), and 21% date from before 1960. Owners live in 77% of the occupied homes (North Carolina: 66%), so for most households a test and a fix are their own to order.
| Homes | Polk County | North Carolina |
|---|---|---|
| Housing units | 10,949 | 4,815,195 |
| Detached houses | 79% | 65% |
| In buildings of 5 or more | 5% | 14% |
| Mobile homes | 12% | 11% |
| Built before 1960 | 21% | 14% |
| Built since 2000 | 21% | 33% |
| Middle year built | 1982 | 1990 |
| Owner-occupied | 77% | 66% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.