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 Rockcastle County, Kentucky
EPA puts Rockcastle County in Zone 2, its middle radon zone, and only 14 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
Highest bordering
59.5%
Pulaski County
- Pulaski
- 59.5%
- Laurel
- 22.0%
5 of 6 neighbours have 30+ tests, 2008 to 2017
Nearest county
35.6%
Lincoln County, 20 miles
- Lincoln
- 35.6%
- Kentucky
- 43.7%
Share at 4+ pCi/L, 135 tests, 2008 to 2017
Ground above low
100.0%
5.7 pts above Kentucky
- Rockcastle
- 100.0%
- Kentucky
- 94.3%
Share of land USGS rates moderate or high potential
Tests reported
14
Too few for a share
- Rockcastle
- 14
- Needed
- 30
2008 to 2017, 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 Rockcastle 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
Rockcastle County, At a glance
Rockcastle County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Rockcastle County is a
USGS geologic potential: Moderate across 86% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Rockcastle County, 2008 to 2017, laboratory
CDC holds 14 reported tests for Rockcastle County over the 2008 to 2017 laboratory totals, with a median of 3.0 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Rockcastle County beside the counties around it is how this page reads it.
What these figures count
Only 14 tests were reported to CDC for Rockcastle 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).
Rockcastle County, Compared
Rockcastle County radon figures, compared
Calculated by Radon411CDC's largest figure for Rockcastle County rests on 14 tests over the 2008 to 2017 laboratory totals, 6 of them at or above 4 pCi/L, so each test moves its share by 7.1 points and no rank or comparison is drawn from it. Results reached as high as 17.6 pCi/L, with a middle value of 3.0 pCi/L.
Of the counties bordering it, 5 have a figure over the 2008 to 2017 laboratory totals: Pulaski County reported the largest share at or above 4 pCi/L, 59.5%, and Laurel County the smallest, 22.0%, with Garrard County at 39.6%, Madison County at 38.7% and Lincoln County at 35.6% between. Farther out, Estill County (30 miles away) at 44.1%, Casey County (34 miles away) at 32.6% and Boyle County (35 miles away) at 53.9% have figures too. 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 Rockcastle County in Zone 2, its middle label: a predicted county average between 2 and 4 pCi/L. USGS geology rates 86% of the county's land moderate radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Rockcastle County, Geology
The ground under Rockcastle County
PredictedMost of the ground under Rockcastle County is one class on USGS's geologic map: 85.7% of its land is moderate radon potential, with 14.3% high. The map puts 69.5% of Rockcastle County in the area it calls Mississippian Plateau and 16.2% in Cumberland Plateau, with 2 smaller areas beside them. USGS gives the first a radon index of 11 and the second 9, both in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Mississippian Plateau | Mississippian marine limestones, dolomites, marine sandstones, siltstones, and shales. | Moderate | 11 | 69.5% |
| Cumberland Plateau | Pennsylvanian sandstones, siltstones, and shales. | Moderate | 9 | 16.2% |
| Eastern Pennyroyal | Marine shale, sandstone and limestone. | High | 12 | 13.1% |
| New Albany-Chattanooga Shale | Devonian/Mississippian Black shale. | High | 14 | 1.1% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Rockcastle County beside the ground around it
On high-potential ground Rockcastle County is close to Kentucky as a whole: 14.3% of its land against 18.2%. Of the 6 counties that border it, 4 have more high-potential ground, Lincoln County the most at 76.7%.
The map rates the ground, not the air in any home.
Local help
Rockcastle County, Local resources
Radon testing and mitigation in Rockcastle 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
Rockcastle County, Questions
Questions about radon in Rockcastle County
Are radon levels high in Rockcastle County?
Over the 2008 to 2017 laboratory totals, 42.9% of the radon tests reported to CDC for Rockcastle County, Kentucky were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.0 pCi/L. Of the counties bordering it, 5 have a figure over the 2008 to 2017 laboratory totals: Pulaski County reported the largest share at or above 4 pCi/L, 59.5%, and Laurel County the smallest, 22.0%, with Garrard County at 39.6%, Madison County at 38.7% and Lincoln County at 35.6% between.
Which counties border Rockcastle County?
Rockcastle County borders 6 counties: Jackson County, Laurel County, Lincoln County, Pulaski County, Madison County and Garrard County.
Products
Rockcastle County, Products
Testing a home in Rockcastle County
No CDC figure names Rockcastle County; the nearest county with one, Lincoln County (20 miles away), reported 35.6% 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 Rockcastle 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
MonitorAranet
Radon Plus battery digital radon monitor with an e-ink screen
- C-NRPP 2024/25: Approved
- Battery
- Bluetooth
- Alarm
- Screen, app
Method: Ion chamber
First reading: Within 10 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Rockcastle County, Bordering counties
Counties bordering Rockcastle County
Calculated by Radon411- Radon levels in Pulaski CountyEPA zone 1
59.5%at or above 4 pCi/L
Median 5.1 pCi/L · 395 tests
- Radon levels in Garrard CountyEPA zone 2
39.6%at or above 4 pCi/L
Median 2.6 pCi/L · 164 tests
- Radon levels in Madison CountyEPA zone 2
38.7%at or above 4 pCi/L
Median 2.9 pCi/L · 604 tests
- Radon levels in Lincoln CountyEPA zone 1
35.6%at or above 4 pCi/L
Median 2.8 pCi/L · 135 tests
- Radon levels in Laurel CountyEPA zone 2
22.0%at or above 4 pCi/L
Median 1.9 pCi/L · 100 tests
- Radon levels in Jackson CountyEPA zone 2
0.0%at or above 4 pCi/L
Median 1.8 pCi/L · 11 tests
Rockcastle County, Cities and towns
Cities and towns in Rockcastle County
The Census Bureau estimates 16,148 residents in Rockcastle County for July 1, 2025, 91 more than in 2020 (+0.6%). That works out to 51 people per square mile of land. No town dominates: Mount Vernon, the largest, has 2,455 residents, 15.2% of the total. Together its 3 incorporated places hold 23.1% of those residents; the other 76.9% live outside any of them. Reported testing is thin here: 14 tests over 2008 to 2017, or 0.9 for every 1,000 residents (2025 estimate), where Kentucky as a whole comes to 6.3.
From Mount Vernon to Livingston, CDC publishes no figure by town: each reads Rockcastle County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Mount Vernon | 2,455 | +0.1% | 15.2% |
| Brodhead | 1,116 | −0.2% | 6.9% |
| Livingston | 165 | Level | 1.0% |
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).
Rockcastle County, Homes
Homes in Rockcastle County
Of Rockcastle County's 7,377 homes, 65% are detached houses, against 68% across Kentucky; 27% are mobile homes. Half of its homes were built before 1988, close to Kentucky's 1982: 15% date from before 1960 and 24% from 2000 or later. Owners live in 76% of the occupied homes (Kentucky: 68%), so for most households a test and a fix are their own to order.
| Homes | Rockcastle County | Kentucky |
|---|---|---|
| Housing units | 7,377 | 2,010,655 |
| Detached houses | 65% | 68% |
| In buildings of 5 or more | 4% | 12% |
| Mobile homes | 27% | 11% |
| Built before 1960 | 15% | 22% |
| Built since 2000 | 24% | 24% |
| Middle year built | 1988 | 1982 |
| Owner-occupied | 76% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.