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, Tennessee
EPA puts Monroe County in Zone 1, its highest radon zone, and only 17 radon tests from it are on file with CDC (2023). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
12.2%
11.6 pts below TN
- Monroe
- 12.2%
- Tennessee
- 23.8%
246 tests, 2022
Median result
1.1pCi/L
Below action level
- Monroe
- 1.1 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2022
Tests reported
246
9th of 34 by tests
- Monroe
- 246
- Knox
- 1,599
Reported to CDC before any fix, 2022
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in Tennessee
28 of 34
Lowest quarter
- Monroe
- 12.2%
- Putnam
- 55.0%
By share, of 34 with 30+ tests
Read a result for Monroe County
Starts at Monroe County's median, 1.1 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 1.1 pCi/L
Below 2 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is below 2 pCi/L, the level at which EPA says a fix should be considered. Monroe County's median reported result, 2022.
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: Moderate across 50% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Monroe County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2022 | 12.2% |
| 2023 | 17.6% |
2023: 17.6%. Across these years the share ran from 12.2% to 17.6%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 17 tests were reported to CDC for Monroe County over 2023, 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: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).
Monroe County, Compared
Monroe County radon figures, compared
Calculated by Radon411Monroe County reports fewer high tests than Tennessee overall. 12.2% of its 246 tests in 2022 were at or above 4 pCi/L. That is 11.6 points below the 23.8% pooled from 78 Tennessee counties.
The newest figure, in 2023, counts only 17 tests (17.6% at or above 4 pCi/L), too few to compare, so this reading uses the 246-test figure.
Ordered from highest share down, it comes 28th of 34 Tennessee counties with 30 or more tests for the same period. Nationally, every county with a figure for the same period pools to 23.9%; Monroe County sits 11.7 points below it.
Next door, the shares run from 18.2% in Polk County to 31.4% in Loudon County. The reported tests do not follow EPA's Zone 1 label for Monroe County (predicted average above 4 pCi/L): 12.2% of them reached 4 pCi/L, fewer than that label suggests.
Half the tests came in under 1.1 pCi/L and half over it; the single highest reached 15.4 pCi/L. The rest split 69.5% under 2 pCi/L and 18.3% from 2 to 4 (Tennessee: 52.1% and 24.1%).
The busiest year on file was 2022, with 246 tests reported; the quietest, 2023, had 17.
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 splits Monroe County: 50.0% of its land is moderate radon potential and 50.0% high. The map puts 50.0% of Monroe County in the area it calls Ridge and Valley and 49.7% in Unaka Mountains. USGS gives the first a radon index of 14, in the high band (12 to 17), and the second 11, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Ridge and Valley | Paleozoic sandstone and cherty dolostone. | High | 14 | 50.0% |
| Unaka Mountains | Precambrian and Paleozoic siltstone, sandstone, conglomerate, quartzite, phyllite, gneiss, granite, and metamorphosed volcanic rock. | Moderate | 11 | 49.7% |
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
On high-potential ground Monroe County is close to Tennessee as a whole: 50.0% of its land against 47.2%. Of the 6 counties that border it, 3 have more high-potential ground, Loudon County the most 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
- Tennessee Radon ProgramTennessee Radon Program, run by Department of Environment & Conservation, offers free or discounted test kits, and answers questions about testing and mitigation in Tennessee.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
The Tennessee Radon Program provides free radon test kits and information assistance to residents, while also providing training opportunities to radon professionals across the state.
- Compare kits
- Professionals in Tennessee1 professional is listed in Tennessee.
What Tennessee's program says
- Phone
- 1-800-232-1139
- TDEC.Radon@tn.gov
What it means
Monroe County, Questions
Questions about radon in Monroe County
Are radon levels high in Monroe County?
In 2023, 17.6% of the radon tests reported to CDC for Monroe County, Tennessee were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.6 pCi/L. Of 34 Tennessee counties with 30 or more tests for the same period, 27 reported a higher share; pooled, the state comes to 23.8%.
Which counties border Monroe County?
Monroe County borders 6 counties: Loudon County, TN, Graham County, NC, Cherokee County, NC, McMinn County, TN, Blount County, TN and Polk County, TN.
Products
Monroe County, Products
Testing a home in Monroe County
In Monroe County, 12.2% of 246 tests reported to CDC in 2022 reached 4 pCi/L, against 23.8% pooled across Tennessee. 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
Wave Radon battery smart radon monitor
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- App only
Method: Alpha spectrometry
Short-term kitFirst Alert
RD1 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 2 to 4 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
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Monroe County, Bordering counties
Counties bordering Monroe County
Calculated by Radon411- Radon levels in Cherokee County, NCEPA zone 1
60.0%at or above 4 pCi/L
Median 5.0 pCi/L · 5 tests · 47.8 points above Monroe County
- Radon levels in Loudon County, TNEPA zone 1
31.4%at or above 4 pCi/L
Median 2.3 pCi/L · 306 tests · 19.2 points above Monroe County
- Radon levels in Blount County, TNEPA zone 1
29.0%at or above 4 pCi/L
Median 2.2 pCi/L · 321 tests · 16.8 points above Monroe County
- Radon levels in Polk County, TNEPA zone 2
18.2%at or above 4 pCi/L
Median 2.6 pCi/L · 33 tests · 6.0 points above Monroe County
- Radon levels in McMinn County, TNEPA zone 1
0.0%at or above 4 pCi/L
Median 1.4 pCi/L · 15 tests · 12.2 points below Monroe County
- Radon levels in Graham County, NCEPA zone 2
No CDC figure for 2022; its page reads it against its own neighbours.
Monroe County, Cities and towns
Cities and towns in Monroe County
Monroe County is growing: the Census Bureau puts it at 49,730 residents on July 1, 2025, up 7.2% from 46,399 in 2020. That works out to 78 people per square mile of land. Sweetwater, the largest place on its list (6,706 residents in all), extends beyond Monroe County, so no share of the total is worked out for it. Testing is reported here more often than across the state: CDC's 246 reported tests for 2022 come to 4.9 for every 1,000 residents (2025 estimate), against 1.3 for Tennessee.
From Sweetwater to Tellico Plains, CDC publishes no figure by town: each reads Monroe County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Sweetwaterextends beyond Monroe County | 6,706 | +4.3% | Counted whole |
| Madisonville | 5,428 | +5.5% | 10.9% |
| Vonoreextends beyond Monroe County | 1,715 | +8.3% | Counted whole |
| Tellico Plains | 778 | +2.9% | 1.6% |
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 Monroe County is counted whole, so it has no share.
Monroe County, Homes
Homes in Monroe County
Of Monroe County's 21,555 homes, 67% are detached houses, against 68% across Tennessee; 23% are mobile homes. Half of its homes were built before 1991, close to Tennessee's 1986: 10% date from before 1960 and 34% from 2000 or later. 72% of occupied homes are lived in by their owner (Tennessee: 67%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Monroe County | Tennessee |
|---|---|---|
| Housing units | 21,555 | 3,095,472 |
| Detached houses | 67% | 68% |
| In buildings of 5 or more | 4% | 14% |
| Mobile homes | 23% | 8% |
| Built before 1960 | 10% | 18% |
| Built since 2000 | 34% | 29% |
| Middle year built | 1991 | 1986 |
| Owner-occupied | 72% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.