Short-term kit
Air Chek Short-Term radon test kit you hang, lab fee included
- Lab fee included
In home: 72 to 168 hours
Locations and reports
Radon Levels in Mason County, Kentucky
EPA puts Mason County in Zone 2, its middle radon zone, and 25.0% of its 32 reported radon tests (2008 to 2017, laboratory totals) were at or above 4 pCi/L. Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
25.0%
18.7 pts below KY
- Mason
- 25.0%
- Kentucky
- 43.7%
32 tests, 2008 to 2017
Median result
2.6pCi/L
Below action level
- Mason
- 2.6 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
32
67th of 69 by tests
- Mason
- 32
- Jefferson
- 6,590
Reported to CDC before any fix, 2008 to 2017
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
54 of 69
Lowest quarter
- Mason
- 25.0%
- Meade
- 68.4%
By share, of 69 with 30+ tests
Read a result for Mason County
Starts at Mason County's median, 2.6 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.6 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. Mason County's median reported result, 2008 to 2017.
The data
Mason County, At a glance
Mason County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Mason County is a
USGS geologic potential: Moderate across 99% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Mason County, 2008 to 2017, laboratory
Under 2 pCi/L: 38%2 to 4 pCi/L: 37%4 pCi/L and above: 25%
Of 32 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 12 | 37.5% |
| 2 to 4 pCi/L | 12 | 37.5% |
| 4 pCi/L and above | 8 | 25.0% |
What these figures count
These are the 32 tests reported to CDC for Mason County over 2008 to 2017 (laboratory totals), many from homes being sold or already suspected of a problem: they describe the county's reported tests, not this house.
Measured: CDC tracking data. Figure above: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).
Mason County, Compared
Mason County radon figures, compared
Calculated by Radon411Mason County's 32 reported tests over the 2008 to 2017 laboratory totals had a middle value of 2.6 pCi/L and a maximum of 43.1 pCi/L, and 25.0% reached 4 pCi/L. Kentucky as a whole (120 Kentucky counties, pooled) comes to 43.7%: 18.7 points higher than here.
Among its state's counties it ranks 54th of 69 Kentucky counties with 30 or more tests for the same period. Statewide for the same period, Meade County reported the highest share (68.4%) and Hopkins County the lowest (9.5%).
Below the action level, 12 tests (37.5%) came in under 2 pCi/L, against 33.2% statewide, and 12 tests (37.5%) fell between 2 and 4, against 23.1% statewide. CDC's ten-year totals for Mason County went from 27 tests (2005 to 2014) to 32 (2008 to 2017), the share going from 22.2% to 25.0%.
EPA's 1993 zone map puts Mason County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 99% of the county's land moderate radon potential.
Brown County, OH, the one bordering county with a figure for the same period, reported 47.1%.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Mason County, Geology
The ground under Mason County
PredictedMost of the ground under Mason County is one class on USGS's geologic map: 99.3% of its land is moderate radon potential, with 0.7% high. 98.8% of it lies in the area the map calls Outer Bluegrass, 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 |
|---|---|---|---|---|
| Outer Bluegrass | Ordovician-Devonian limestone and shale. | Moderate | 11 | 98.8% |
| New Albany-Chattanooga Shale | Devonian/Mississippian Black shale. | High | 14 | 0.7% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Mason County beside the ground around it
Kentucky as a whole has more high-potential ground than Mason County: 18.2% of its land, against 0.7% here. Of the 6 counties that border it, 5 have more high-potential ground, Adams County, OH the most at 58.3%.
The map rates the ground, not the air in any home.
Local help
Mason County, Local resources
Radon testing and mitigation in Mason 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
Mason County, Questions
Questions about radon in Mason County
Are radon levels high in Mason County?
Over the 2008 to 2017 laboratory totals, 25.0% of the radon tests reported to CDC for Mason County, Kentucky were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.6 pCi/L. Of 69 Kentucky counties with 30 or more tests for the same period, 53 reported a higher share; pooled, the state comes to 43.7%.
Which counties border Mason County?
Mason County borders 6 counties: Bracken County, KY, Robertson County, KY, Brown County, OH, Fleming County, KY, Lewis County, KY and Adams County, OH.
Products
Mason County, Products
Testing a home in Mason County
In Mason County, 25.0% of 32 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 43.7% pooled across Kentucky. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Mason 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
XR0A-iR Wi-Fi battery radon detector with a screen
- C-NRPP 2024/25: Not included
- Battery
- Wi-Fi
- Screen, app
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
Mason County, Bordering counties
Counties bordering Mason County
Calculated by Radon411- Radon levels in Adams County, OHEPA zone 1
50.0%at or above 4 pCi/L
Median 3.8 pCi/L · 18 tests · 25.0 points above Mason County
- Radon levels in Brown County, OHEPA zone 2
47.1%at or above 4 pCi/L
Median 3.3 pCi/L · 70 tests · 22.1 points above Mason County
- Radon levels in Fleming County, KYEPA zone 2
36.4%at or above 4 pCi/L
Median 2.9 pCi/L · 22 tests · 11.4 points above Mason County
- Radon levels in Lewis County, KYEPA zone 2
33.3%at or above 4 pCi/L
Median 2.8 pCi/L · 12 tests · 8.3 points above Mason County
- Radon levels in Robertson County, KYEPA zone 1
25.0%at or above 4 pCi/L
Median 1.1 pCi/L · 4 tests · 0.0 points above Mason County
- Radon levels in Bracken County, KYEPA zone 2
20.0%at or above 4 pCi/L
Median 2.0 pCi/L · 5 tests · 5.0 points below Mason County
Mason County, Cities and towns
Cities and towns in Mason County
About 16,936 people live in Mason County by the Census Bureau's estimate for July 1, 2025, 199 fewer than in 2020 (−1.2%). That works out to 71 people per square mile of land. Maysville alone is home to 8,688 of them, 51.3% of the total. Reported testing is thin here: 32 tests over 2008 to 2017, or 1.9 for every 1,000 residents (2025 estimate), where Kentucky as a whole comes to 6.3.
From Maysville to Sardis, CDC publishes no figure by town: each reads Mason County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Maysville | 8,688 | −1.8% | 51.3% |
| Dover | 220 | Level | 1.3% |
| Germantownextends beyond Mason County | 144 | +1.4% | Counted whole |
| Sardisextends beyond Mason County | 61 | −1.6% | Counted whole |
4 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 Mason County is counted whole, so it has no share.
Mason County, Homes
Homes in Mason County
Of Mason County's 8,186 homes, 69% are detached houses, against 68% across Kentucky; 11% are in buildings of five or more homes. Half of its homes were built before 1976, close to Kentucky's 1982: 32% date from before 1960 and 18% from 2000 or later. 69% 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 | Mason County | Kentucky |
|---|---|---|
| Housing units | 8,186 | 2,010,655 |
| Detached houses | 69% | 68% |
| In buildings of 5 or more | 11% | 12% |
| Mobile homes | 9% | 11% |
| Built before 1960 | 32% | 22% |
| Built since 2000 | 18% | 24% |
| Middle year built | 1976 | 1982 |
| Owner-occupied | 69% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.