Short-term kitKidde
442020 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 3 days
Locations and reports
Radon Levels in Union County, Kentucky
EPA puts Union County in Zone 2, its middle radon zone, and only 8 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
35.3%
Posey County
- Posey
- 35.3%
- Henderson
- 24.1%
2 of 6 neighbours have 30+ tests, 2008 to 2017
Nearest county
24.1%
Henderson County, 22 miles
- Henderson
- 24.1%
- Kentucky
- 43.7%
Share at 4+ pCi/L, 54 tests, 2008 to 2017
Ground above low
100.0%
5.7 pts above Kentucky
- Union
- 100.0%
- Kentucky
- 94.3%
Share of land USGS rates moderate or high potential
Tests reported
8
Too few for a share
- Union
- 8
- 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 Union 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
Union County, At a glance
Union County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Union 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 Union County, 2008 to 2017, laboratory
CDC holds 8 reported tests for Union County over the 2008 to 2017 laboratory totals, with a median of 1.6 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Union County beside the counties around it is how this page reads it.
What these figures count
Only 8 tests were reported to CDC for Union 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).
Union County, Compared
Union County radon figures, compared
Calculated by Radon411CDC's largest figure for Union County rests on 8 tests over the 2008 to 2017 laboratory totals, 2 of them at or above 4 pCi/L, so each test moves its share by 12.5 points and no rank or comparison is drawn from it. Results reached as high as 5.7 pCi/L, with a middle value of 1.6 pCi/L.
Of the counties bordering it, 2 have a figure over the 2008 to 2017 laboratory totals: Posey County, IN reported the largest share at or above 4 pCi/L, 35.3%, and Henderson County the smallest, 24.1%. Farther out, Hopkins County (33 miles away) at 9.5%, Daviess County (47 miles away) at 20.0% and Marshall County (57 miles away) at 10.6% 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 Union 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.
Union County, Geology
The ground under Union County
PredictedUSGS's geologic map puts all of Union County's mapped land in one class: moderate radon potential. 98.8% of it lies in the area the map calls Western Coalfield, 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 |
|---|---|---|---|---|
| Western Coalfield | Limestones, shale, siltstone, and coal beds. | Moderate | 9 | 98.8% |
| Shawnee Hills Section | Unglaciated Ordovician to Pennsylvanian limestone, sandstone, and shale. | Moderate | 10 | 1.1% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Union County beside the ground around it
Across Kentucky 18.2% of the land is rated high; none of Union County's is. Of the 6 counties that border it, none has as large a share of moderate-potential ground; Crittenden County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Union County, Local resources
Radon testing and mitigation in Union 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
Union County, Questions
Questions about radon in Union County
Are radon levels high in Union County?
Over the 2008 to 2017 laboratory totals, 25.0% of the radon tests reported to CDC for Union County, Kentucky were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.6 pCi/L. Of the counties bordering it, 2 have a figure over the 2008 to 2017 laboratory totals: Posey County, IN reported the largest share at or above 4 pCi/L, 35.3%, and Henderson County the smallest, 24.1%.
Which counties border Union County?
Union County borders 6 counties: Gallatin County, IL, Webster County, KY, Hardin County, IL, Henderson County, KY, Posey County, IN and Crittenden County, KY.
Products
Union County, Products
Testing a home in Union County
No CDC figure names Union County; the nearest county with one, Henderson County (22 miles away), reported 24.1% 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 Union 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
RadonEye RD200 plug-in continuous radon monitor
- C-NRPP 2024/25: Approved
- Plug-in
- 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
Union County, Bordering counties
Counties bordering Union County
Calculated by Radon411- Radon levels in Posey County, INEPA zone 2
35.3%at or above 4 pCi/L
Median 2.8 pCi/L · 215 tests
- Radon levels in Gallatin County, ILEPA zone 2
33.3%at or above 4 pCi/L
Median 2.0 pCi/L · 6 tests
- Radon levels in Crittenden County, KYEPA zone 2
25.0%at or above 4 pCi/L
Median 1.6 pCi/L · 8 tests
- Radon levels in Henderson County, KYEPA zone 2
24.1%at or above 4 pCi/L
Median 2.3 pCi/L · 54 tests
- Radon levels in Hardin County, ILEPA zone 2
22.2%at or above 4 pCi/L
Median 1.4 pCi/L · 9 tests
- Radon levels in Webster County, KYEPA zone 2
12.5%at or above 4 pCi/L
Median 2.0 pCi/L · 8 tests
Union County, Cities and towns
Cities and towns in Union County
Union County has been losing residents: from 13,644 in 2020 to 12,839 on July 1, 2025, a fall of 5.9% by the Census Bureau's estimates. That works out to 37 people per square mile of land. Its largest town, Morganfield, has 3,102 residents, 24.2% of the total. Together its 4 incorporated places hold 46.3% of those residents; the other 53.7% live outside any of them. Reported testing is thin here: 8 tests over 2008 to 2017, or 0.6 for every 1,000 residents (2025 estimate), where Kentucky as a whole comes to 6.3.
From Morganfield to Waverly, CDC publishes no figure by town: each reads Union County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Morganfield | 3,102 | −4.5% | 24.2% |
| Sturgis | 1,637 | −5.5% | 12.8% |
| Uniontown | 901 | −3.0% | 7.0% |
| Waverly | 301 | −3.8% | 2.3% |
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).
Union County, Homes
Homes in Union County
Union County is a place of houses on their own lots: 77% of its 5,868 homes are detached single-family houses, against 68% across Kentucky. Half of its homes were built before 1975, close to Kentucky's 1982: 30% date from before 1960 and 11% from 2000 or later. 72% 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 | Union County | Kentucky |
|---|---|---|
| Housing units | 5,868 | 2,010,655 |
| Detached houses | 77% | 68% |
| In buildings of 5 or more | 3% | 12% |
| Mobile homes | 15% | 11% |
| Built before 1960 | 30% | 22% |
| Built since 2000 | 11% | 24% |
| Middle year built | 1975 | 1982 |
| Owner-occupied | 72% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.