Short-term kit
Radon Short Term Test Kit short-term charcoal radon test kit, lab fee included
- Lab fee included
Method: Charcoal
In home: 2 to 7 days
Locations and reports
Radon Levels in Knox County, Kentucky
EPA puts Knox County in Zone 2, its middle radon zone, and only 29 radon tests from it are on file with CDC (2008 to 2017, laboratory totals). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
10.0%
35.1 pts below KY
- Knox
- 10.0%
- Kentucky
- 45.1%
30 tests, 2007 to 2016
Median result
2.0pCi/L
Below action level
- Knox
- 2.0 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2007 to 2016
Tests reported
30
69th of 69 by tests
- Knox
- 30
- Jefferson
- 5,581
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 Kentucky
68 of 69
Lowest quarter
- Knox
- 10.0%
- Meade
- 71.6%
By share, of 69 with 30+ tests
Read a result for Knox County
Starts at Knox County's median, 2.0 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.0 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. Knox County's median reported result, 2007 to 2016.
The data
Knox County, At a glance
Knox County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Knox 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 Knox County, 2008 to 2017, laboratory
CDC holds 29 reported tests for Knox County over the 2008 to 2017 laboratory totals, with a median of 2.1 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Knox County beside the counties around it is how this page reads it.
What these figures count
Only 29 tests were reported to CDC for Knox County over 2008 to 2017 (laboratory totals), 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: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).
Knox County, Compared
Knox County radon figures, compared
Calculated by Radon411Knox County reports fewer high tests than Kentucky overall. 10.0% of its 30 tests over the 2007 to 2016 laboratory totals were at or above 4 pCi/L. That is 35.1 points below the 45.1% pooled from 120 Kentucky counties.
The newest figure, over the 2008 to 2017 laboratory totals, counts only 29 tests (10.3% at or above 4 pCi/L), too few to compare, so this reading uses the 30-test figure.
Ordered from highest share down, it comes 68th of 69 Kentucky counties with 30 or more tests for the same period. Nationally, every county with a figure for the same period pools to 35.8%; Knox County sits 25.8 points below it.
Laurel County, the one bordering county with a figure for the same period, reported 21.6%. Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 10.0% share point the same way here.
Half the tests came in under 2.0 pCi/L and half over it; the single highest reached 6.6 pCi/L. The rest split 50.0% under 2 pCi/L and 40.0% from 2 to 4 (Kentucky: 31.6% and 23.3%).
CDC's ten-year totals for Knox County went from 22 tests (2005 to 2014) to 29 (2008 to 2017), the share going from 13.6% to 10.3%.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Knox County, Geology
The ground under Knox County
PredictedUSGS's geologic map puts all of Knox County's mapped land in one class: moderate radon potential. All of it lies in the area the map calls Cumberland Plateau, to which USGS gives a radon index of 9, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Cumberland Plateau | Pennsylvanian sandstones, siltstones, and shales. | Moderate | 9 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Knox County beside the ground around it
Across Kentucky 18.2% of the land is rated high; none of Knox County's is. Of the 4 counties that border it, 1 has more high-potential ground, Bell County the most at 4.5%.
The map rates the ground, not the air in any home.
Local help
Knox County, Local resources
Radon testing and mitigation in Knox County
- Kentucky's radon programKentucky Board of Radon SafetyKentucky's radon program answers questions about testing, mitigation and the rules in Kentucky.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 Kentucky8 professionals are listed in Kentucky.
What Kentucky's program says
- Phone
- 502-782-2782
- Radon@ky.gov
What it means
Knox County, Questions
Questions about radon in Knox County
Are radon levels high in Knox County?
Over the 2008 to 2017 laboratory totals, 10.3% of the radon tests reported to CDC for Knox County, Kentucky were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.1 pCi/L. Of 69 Kentucky counties with 30 or more tests for the same period, 67 reported a higher share; pooled, the state comes to 45.1%.
Which counties border Knox County?
Knox County borders 4 counties: Bell County, Whitley County, Clay County and Laurel County.
Products
Knox County, Products
Testing a home in Knox County
In Knox County, 10.0% of 30 tests reported to CDC over the 2007 to 2016 laboratory totals reached 4 pCi/L, against 45.1% pooled across Kentucky. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Knox 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
MonitorX-Sense
XR0B-SR battery digital radon monitor with an alarm
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- 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
Knox County, Bordering counties
Counties bordering Knox County
Calculated by Radon411- Radon levels in Clay CountyEPA zone 2
25.0%at or above 4 pCi/L
Median 2.3 pCi/L · 8 tests · 15.0 points above Knox County
- Radon levels in Laurel CountyEPA zone 2
21.6%at or above 4 pCi/L
Median 2.0 pCi/L · 97 tests · 11.6 points above Knox County
- Radon levels in Bell CountyEPA zone 2
20.0%at or above 4 pCi/L
Median 1.3 pCi/L · 5 tests · 10.0 points above Knox County
- Radon levels in Whitley CountyEPA zone 2
18.5%at or above 4 pCi/L
Median 2.0 pCi/L · 27 tests · 8.5 points above Knox County
Knox County, Cities and towns
Cities and towns in Knox County
About 29,532 people live in Knox County by the Census Bureau's estimate for July 1, 2025, 654 fewer than in 2020 (−2.2%). That works out to 76 people per square mile of land. Corbin, the largest place on its list (7,911 residents in all), extends beyond Knox County, so no share of the total is worked out for it. Reported testing is thin here: 30 tests over 2007 to 2016, or 1.0 for every 1,000 residents (2025 estimate), where Kentucky as a whole comes to 5.7.
From Corbin to Barbourville, CDC publishes no figure by town: each reads Knox County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Corbinextends beyond Knox County | 7,911 | +1.0% | Counted whole |
| Barbourville | 3,064 | −4.9% | 10.4% |
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 Knox County is counted whole, so it has no share.
Knox County, Homes
Homes in Knox County
Of Knox County's 13,824 homes, 57% are detached houses, against 68% across Kentucky; 31% are mobile homes. Half of its homes were built before 1985, close to Kentucky's 1982: 15% date from before 1960 and 20% from 2000 or later. 66% of occupied homes are lived in by their owner (Kentucky: 68%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Knox County | Kentucky |
|---|---|---|
| Housing units | 13,824 | 2,010,655 |
| Detached houses | 57% | 68% |
| In buildings of 5 or more | 7% | 12% |
| Mobile homes | 31% | 11% |
| Built before 1960 | 15% | 22% |
| Built since 2000 | 20% | 24% |
| Middle year built | 1985 | 1982 |
| Owner-occupied | 66% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.