Short-term kit
PicoCan short-term charcoal canister radon test
- Lab fee included
Method: Charcoal
In home: 48 to 96 hours
Locations and reports
Radon Levels in Johnson County, Kentucky
EPA puts Johnson County in Zone 2, its middle radon zone, and only 28 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
Nearest county
31.7%
Carter County, 35 miles
- Carter
- 31.7%
- Kentucky
- 43.7%
Share at 4+ pCi/L, 41 tests, 2008 to 2017
Ground above low
100.0%
5.7 pts above Kentucky
- Johnson
- 100.0%
- Kentucky
- 94.3%
Share of land USGS rates moderate or high potential
Tests reported
29
Too few for a share
- Johnson
- 29
- Needed
- 30
2006 to 2015, laboratory
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
EPA predicts 2 to 4 pCi/L indoors
Read a result for Johnson County
Starts at EPA's action level
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 4.0 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.
The data
Johnson County, At a glance
Johnson County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Johnson 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 Johnson County, 2008 to 2017, laboratory
CDC holds 28 reported tests for Johnson County over the 2008 to 2017 laboratory totals, with a median of 0.8 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Johnson County beside the counties around it is how this page reads it.
What these figures count
Only 28 tests were reported to CDC for Johnson 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).
Johnson County, Compared
Johnson County radon figures, compared
Calculated by Radon411CDC's largest figure for Johnson County rests on 29 tests over the 2006 to 2015 laboratory totals, 0 of them at or above 4 pCi/L, so each test moves its share by 3.4 points and no rank or comparison is drawn from it. Results reached as high as 2.9 pCi/L, with a middle value of 0.8 pCi/L.
The nearest counties with a figure are Carter County (35 miles away) at 31.7%, Breathitt County (35 miles away) at 19.1% and Pike County (35 miles away) at 17.1%. Pooled across 120 Kentucky counties, 43.7% of reported tests reached that level; across every county in the country with a figure, 35.7%.
Statewide for the same period, Meade County reported the highest share (68.4%) and Hopkins County the lowest (9.5%). EPA's 1993 map puts Johnson County in Zone 2, its middle label: a predicted county average between 2 and 4 pCi/L. USGS geology rates 100% of the county's land moderate radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Johnson County, Geology
The ground under Johnson County
PredictedUSGS's geologic map puts all of Johnson 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.
Johnson County beside the ground around it
Across Kentucky 18.2% of the land is rated high; none of Johnson County's is. Of the 5 counties that border it, none has as large a share of moderate-potential ground; Floyd County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Johnson County, Local resources
Radon testing and mitigation in Johnson 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
Johnson County, Questions
Questions about radon in Johnson County
Are radon levels high in Johnson County?
Over the 2008 to 2017 laboratory totals, 0.0% of the radon tests reported to CDC for Johnson County, Kentucky were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.8 pCi/L. Of the 8 nearest counties with a figure, within 60 miles, the share of tests at or above 4 pCi/L runs from 12.5% to 51.4%.
Which counties border Johnson County?
Johnson County borders 5 counties: Lawrence County, Martin County, Magoffin County, Morgan County and Floyd County.
Products
Johnson County, Products
Testing a home in Johnson County
No CDC figure names Johnson County; the nearest county with one, Carter County (35 miles away), reported 31.7% of its tests at or above 4 pCi/L over the 2008 to 2017 laboratory totals, the only reading nearby until a test of this home. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Johnson County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL416 long-term radon test kit, lab fee included
- Lab fee included
Method: Alpha track
In home: 90 days to 12 months
Monitor
RM-65 rechargeable radon detector with a color screen and alarm
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
First reading: Within 6 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Johnson County, Bordering counties
Counties bordering Johnson County
Calculated by Radon411- Radon levels in Floyd CountyEPA zone 2
40.0%at or above 4 pCi/L
Median 2.7 pCi/L · 20 tests
- Radon levels in Morgan CountyEPA zone 2
5.6%at or above 4 pCi/L
Median 1.2 pCi/L · 18 tests
- Radon levels in Lawrence CountyEPA zone 2
0.0%at or above 4 pCi/L
Median 1.7 pCi/L · 9 tests
- Radon levels in Martin CountyEPA zone 2
0.0%at or above 4 pCi/L
Median 0.1 pCi/L · 2 tests
- Radon levels in Magoffin CountyEPA zone 2
0.0%at or above 4 pCi/L
Median 0.5 pCi/L · 13 tests
Johnson County, Cities and towns
Cities and towns in Johnson County
About 22,051 people live in Johnson County by the Census Bureau's estimate for July 1, 2025, 597 fewer than in 2020 (−2.6%). That works out to 84 people per square mile of land. Paintsville, its one incorporated place, has 4,111 residents, 18.6% of the total. Reported testing is thin here: 29 tests over 2006 to 2015, or 1.3 for every 1,000 residents (2025 estimate), where Kentucky as a whole comes to 5.0.
Paintsville is the one incorporated place here; CDC publishes no figure by town, so it reads Johnson County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Paintsville | 4,111 | −4.6% | 18.6% |
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).
Johnson County, Homes
Homes in Johnson County
Of Johnson County's 10,530 homes, 60% are detached houses, against 68% across Kentucky; 27% are mobile homes. Half of its homes were built before 1984, close to Kentucky's 1982: 18% date from before 1960 and 23% 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 | Johnson County | Kentucky |
|---|---|---|
| Housing units | 10,530 | 2,010,655 |
| Detached houses | 60% | 68% |
| In buildings of 5 or more | 9% | 12% |
| Mobile homes | 27% | 11% |
| Built before 1960 | 18% | 22% |
| Built since 2000 | 23% | 24% |
| Middle year built | 1984 | 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.