Short-term kitFirst Alert
RD1 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 2 to 4 days
Locations and reports
Radon Levels in Marion County, Tennessee
EPA puts Marion County in Zone 2, its middle radon zone, and only 5 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
28.4%
4.9 pts below TN
- Marion
- 28.4%
- Tennessee
- 33.3%
74 tests, 2008 to 2017
Median result
1.6pCi/L
Below action level
- Marion
- 1.6 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
74
50th of 80 by tests
- Marion
- 74
- Davidson
- 5,592
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 Tennessee
42 of 80
Middle half
- Marion
- 28.4%
- Jefferson
- 56.8%
By share, of 80 with 30+ tests
Read a result for Marion County
Starts at Marion County's median, 1.6 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 1.6 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. Marion County's median reported result, 2008 to 2017.
The data
Marion County, At a glance
Marion County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Marion County is a
USGS geologic potential: Low across 51% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Marion County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2022 | 100.0% |
| 2023 | 60.0% |
2023: 60.0%. Across these years the share ran from 60.0% to 100.0%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 5 tests were reported to CDC for Marion 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).
Marion County, Compared
Marion County radon figures, compared
Calculated by Radon411Marion County's 74 reported tests over the 2008 to 2017 laboratory totals had a middle value of 1.6 pCi/L and a maximum of 36.4 pCi/L, and 28.4% reached 4 pCi/L. Tennessee as a whole (95 Tennessee counties, pooled) comes to 33.3%: 4.9 points higher than here.
The newest figure, in 2023, counts only 5 tests (60.0% at or above 4 pCi/L), too few to compare, so this reading uses the 74-test figure.
Among its state's counties it ranks 42nd of 80 Tennessee counties with 30 or more tests for the same period. Statewide for the same period, Jefferson County reported the highest share (56.8%) and Chester County the lowest (0.0%).
Below the action level, 41 tests (55.4%) came in under 2 pCi/L, against 42.4% statewide, and 12 tests (16.2%) fell between 2 and 4, against 24.3% statewide. The busiest year on file was 2022, with 6 tests reported; the quietest, 2023, had 5.
EPA's 1993 zone map puts Marion County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 51% of the county's land low radon potential.
Next door, the shares run from 17.5% in Jackson County, AL to 25.6% in Franklin County, with Franklin County, Sequatchie County and Hamilton County below Marion County.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Marion County, Geology
The ground under Marion County
PredictedUSGS's geologic map splits Marion County: 50.7% of its land is low radon potential and 49.3% high. The map puts 50.7% of Marion County in the area it calls Appalachian Plateau and 49.2% in Interior Low Plateaus. USGS gives the first a radon index of 8, in the low band (5 to 8), and the second 12, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Appalachian Plateau | Sandstone and shale. | Low | 8 | 50.7% |
| Interior Low Plateaus | Mississippian carbonate rocks and shales. | High | 12 | 49.2% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Marion County beside the ground around it
On high-potential ground Marion County is close to Tennessee as a whole: 49.3% of its land against 47.2%. Of the 6 counties that border it, 2 have more high-potential ground, Jackson County, AL the most at 84.8%.
The map rates the ground, not the air in any home.
Local help
Marion County, Local resources
Radon testing and mitigation in Marion 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
Marion County, Questions
Questions about radon in Marion County
Are radon levels high in Marion County?
In 2023, 60.0% of the radon tests reported to CDC for Marion County, Tennessee were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.6 pCi/L. Of 80 Tennessee counties with 30 or more tests for the same period, 41 reported a higher share; pooled, the state comes to 33.3%.
Which counties border Marion County?
Marion County borders 6 counties: Grundy County, TN, Sequatchie County, TN, Franklin County, TN, Dade County, GA, Hamilton County, TN and Jackson County, AL.
Products
Marion County, Products
Testing a home in Marion County
In Marion County, 28.4% of 74 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 33.3% pooled across Tennessee. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Marion 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
Monitor
EcoQube Flex battery digital radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- Alarm
- Screen, app
Method: Ion chamber
First reading: Within 15 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Marion County, Bordering counties
Counties bordering Marion County
Calculated by Radon411- Radon levels in Franklin County, TNEPA zone 3
25.6%at or above 4 pCi/L
Median 2.1 pCi/L · 266 tests · 2.8 points below Marion County
- Radon levels in Sequatchie County, TNEPA zone 3
20.7%at or above 4 pCi/L
Median 1.9 pCi/L · 58 tests · 7.7 points below Marion County
- Radon levels in Hamilton County, TNEPA zone 2
19.3%at or above 4 pCi/L
Median 1.7 pCi/L · 1,148 tests · 9.1 points below Marion County
- Radon levels in Dade County, GAEPA zone 3
17.6%at or above 4 pCi/L
Median 1.5 pCi/L · 17 tests · 10.8 points below Marion County
- Radon levels in Jackson County, ALEPA zone 1
17.5%at or above 4 pCi/L
Median 1.5 pCi/L · 223 tests · 10.9 points below Marion County
- Radon levels in Grundy County, TNEPA zone 3
0.0%at or above 4 pCi/L
Median 1.0 pCi/L · 29 tests · 28.4 points below Marion County
Marion County, Cities and towns
Cities and towns in Marion County
The Census Bureau estimates 29,804 residents in Marion County for July 1, 2025, 930 more than in 2020 (+3.2%). That works out to 60 people per square mile of land. No town dominates: Jasper, the largest, has 3,636 residents, 12.2% of the total. Reported testing is thin here: 74 tests over 2008 to 2017, or 2.5 for every 1,000 residents (2025 estimate), where Tennessee as a whole comes to 4.2.
From Jasper to Orme, CDC publishes no figure by town: each reads Marion County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Jasper | 3,636 | +0.6% | 12.2% |
| South Pittsburg | 2,927 | −5.2% | 9.8% |
| Kimball | 1,633 | +5.5% | 5.5% |
| Whitwell | 1,596 | −3.3% | 5.4% |
| Monteagleextends beyond Marion County | 1,439 | +3.9% | Counted whole |
| Powells Crossroads | 1,296 | +0.4% | 4.3% |
| New Hope | 968 | −2.7% | 3.2% |
| Orme | 85 | −3.4% | 0.3% |
8 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 Marion County is counted whole, so it has no share.
Marion County, Homes
Homes in Marion County
Of Marion County's 13,837 homes, 75% are detached houses, against 68% across Tennessee; 21% are mobile homes. Half of its homes were built before 1985, close to Tennessee's 1986: 14% date from before 1960 and 25% from 2000 or later. Owners live in 80% of the occupied homes (Tennessee: 67%), so for most households a test and a fix are their own to order.
| Homes | Marion County | Tennessee |
|---|---|---|
| Housing units | 13,837 | 3,095,472 |
| Detached houses | 75% | 68% |
| In buildings of 5 or more | 2% | 14% |
| Mobile homes | 21% | 8% |
| Built before 1960 | 14% | 18% |
| Built since 2000 | 25% | 29% |
| Middle year built | 1985 | 1986 |
| Owner-occupied | 80% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.