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
Locations and reports
Radon Levels in Monroe County, Kentucky
EPA puts Monroe County in Zone 1, its highest radon zone, and high results are common there: 52.9% of the 87 radon tests reported to CDC (2008 to 2017, laboratory totals) came back 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
52.9%
9.2 pts above KY
- Monroe
- 52.9%
- Kentucky
- 43.7%
87 tests, 2008 to 2017
Median result
4.6pCi/L
Action level reached
- Monroe
- 4.6 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
87
38th of 69 by tests
- Monroe
- 87
- Jefferson
- 6,590
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in Kentucky
13 of 69
Top quarter
- Monroe
- 52.9%
- Meade
- 68.4%
By share, of 69 with 30+ tests
Read a result for Monroe County
Starts at Monroe County's median, 4.6 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 4.6 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. Monroe County's median reported result, 2008 to 2017.
The data
Monroe County, At a glance
Monroe County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Monroe County in
USGS geologic potential: High across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Monroe County, 2008 to 2017, laboratory
Under 2 pCi/L: 23%2 to 4 pCi/L: 24%4 pCi/L and above: 53%
Of 87 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 20 | 23.0% |
| 2 to 4 pCi/L | 21 | 24.1% |
| 4 pCi/L and above | 46 | 52.9% |
What these figures count
These are the 87 tests reported to CDC for Monroe 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).
Monroe County, Compared
Monroe County radon figures, compared
Calculated by Radon411More than half: 52.9% of the 87 radon tests reported to CDC for Monroe County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 13th of 69 Kentucky counties with 30 or more tests for the same period. That is 9.2 points above the 43.7% pooled from 120 Kentucky counties.
The median result, 4.6 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 22.2 pCi/L. The rest split 23.0% under 2 pCi/L and 24.1% from 2 to 4 (Kentucky: 33.2% and 23.1%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 52.9% share point the same way here.
No bordering county with a figure for the same period reported a higher share; the closest is Barren County at 51.6%, the lowest Macon County, TN at 19.4%. Statewide for the same period, Meade County reported the highest share (68.4%) and Hopkins County the lowest (9.5%).
CDC's ten-year totals for Monroe County went from 114 tests (2005 to 2014) to 87 (2008 to 2017), the share going from 56.1% to 52.9%.
Nationally, every county with a figure for the same period pools to 35.7%; Monroe County sits 17.2 points above it.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Monroe County, Geology
The ground under Monroe County
PredictedUSGS's geologic map puts all of Monroe County's mapped land in one class: high radon potential. The map puts 81.8% of Monroe County in the area it calls Eastern Pennyroyal and 17.6% in Nashville Basin, with one smaller area beside them. USGS gives the first a radon index of 12 and the second 14, both in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Eastern Pennyroyal | Marine shale, sandstone and limestone. | High | 12 | 81.8% |
| Nashville Basin | Mississippian Limestone. | High | 14 | 17.6% |
| Cherty Highland | Cherty dolostone. | High | 12 | 0.6% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Monroe County beside the ground around it
Monroe County has more high-potential ground than Kentucky as a whole: 100% of its land against 18.2%. Of the 6 counties that border it, none has as large a share of high-potential ground; Macon County, TN comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Monroe County, Local resources
Radon testing and mitigation in Monroe 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
Monroe County, Questions
Questions about radon in Monroe County
Are radon levels high in Monroe County?
Over the 2008 to 2017 laboratory totals, 52.9% of the radon tests reported to CDC for Monroe County, Kentucky were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.6 pCi/L. Of 69 Kentucky counties with 30 or more tests for the same period, 12 reported a higher share; pooled, the state comes to 43.7%.
Which counties border Monroe County?
Monroe County borders 6 counties: Cumberland County, KY, Clay County, TN, Metcalfe County, KY, Macon County, TN, Barren County, KY and Allen County, KY.
Products
Monroe County, Products
Testing a home in Monroe County
In Monroe County, 52.9% of 87 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 43.7% pooled across Kentucky. In Zone 1 the year-round level in Monroe County is the one to know: a long-term test (more than 90 days) or a monitor, with a short-term kit for a first answer.
Test kits and monitors3
See every kit and monitor
Monitor
View Radon Wi-Fi radon monitor with an e-paper display
- C-NRPP 2024/25: Approved
- Battery
- Wi-Fi, Bluetooth
- Screen, app
Method: Alpha spectrometry
Readings: Every 60 minutes
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
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Monroe County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Monroe County
Explore
Monroe County, Bordering counties
Counties bordering Monroe County
Calculated by Radon411- Radon levels in Cumberland County, KYEPA zone 1
55.6%at or above 4 pCi/L
Median 4.6 pCi/L · 18 tests · 2.7 points above Monroe County
- Radon levels in Barren County, KYEPA zone 1
51.6%at or above 4 pCi/L
Median 4.0 pCi/L · 186 tests · 1.3 points below Monroe County
- Radon levels in Metcalfe County, KYEPA zone 1
45.5%at or above 4 pCi/L
Median 3.5 pCi/L · 33 tests · 7.4 points below Monroe County
- Radon levels in Clay County, TNEPA zone 2
34.8%at or above 4 pCi/L
Median 2.3 pCi/L · 46 tests · 18.1 points below Monroe County
- Radon levels in Allen County, KYEPA zone 1
29.3%at or above 4 pCi/L
Median 1.9 pCi/L · 58 tests · 23.6 points below Monroe County
- Radon levels in Macon County, TNEPA zone 1
19.4%at or above 4 pCi/L
Median 1.9 pCi/L · 67 tests · 33.5 points below Monroe County
Monroe County, Cities and towns
Cities and towns in Monroe County
About 11,191 people live in Monroe County by the Census Bureau's estimate for July 1, 2025, 124 fewer than in 2020 (−1.1%). That works out to 34 people per square mile of land. No town dominates: Tompkinsville, the largest, has 2,235 residents, 20.0% of the total. Together its 3 incorporated places hold 26.1% of those residents; the other 73.9% live outside any of them. CDC's 87 reported tests for 2008 to 2017 work out to 7.8 per 1,000 residents (2025 estimate), close to Kentucky's 6.3.
From Tompkinsville to Fountain Run, CDC publishes no figure by town: each reads Monroe County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Tompkinsville | 2,235 | −2.7% | 20.0% |
| Gamaliel | 468 | −2.1% | 4.2% |
| Fountain Run | 217 | Level | 1.9% |
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).
Monroe County, Homes
Homes in Monroe County
Of Monroe County's 5,240 homes, 73% are detached houses, against 68% across Kentucky; 18% are mobile homes. Half of its homes were built before 1977, close to Kentucky's 1982: 19% date from before 1960 and 19% 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 | Monroe County | Kentucky |
|---|---|---|
| Housing units | 5,240 | 2,010,655 |
| Detached houses | 73% | 68% |
| In buildings of 5 or more | 6% | 12% |
| Mobile homes | 18% | 11% |
| Built before 1960 | 19% | 22% |
| Built since 2000 | 19% | 24% |
| Middle year built | 1977 | 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.