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 Davidson County, Tennessee
EPA puts Davidson County in Zone 1, its highest radon zone, and 27.4% of its 146 reported radon tests (2023) 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
27.4%
2.5 pts above TN
- Davidson
- 27.4%
- Tennessee
- 24.9%
146 tests, 2023
Median result
2.2pCi/L
Below action level
- Davidson
- 2.2 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2023
Tests reported
146
5th of 15 by tests
- Davidson
- 146
- Hamblen
- 594
Reported to CDC before any fix, 2023
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
4 of 15
Top quarter
- Davidson
- 27.4%
- Blount
- 50.0%
By share, of 15 with 30+ tests
Read a result for Davidson County
Starts at Davidson County's median, 2.2 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.2 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. Davidson County's median reported result, 2023.
The data
Davidson County, At a glance
Davidson County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Davidson 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 Davidson County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2022 | 21.7% |
| 2023 | 27.4% |
2023: 27.4%. Across these years the share ran from 21.7% to 27.4%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 146 tests reported to CDC for Davidson County over 2023, 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: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).
Davidson County, Compared
Davidson County radon figures, compared
Calculated by Radon411Davidson County's 146 reported tests in 2023 had a middle value of 2.2 pCi/L and a maximum of 49.2 pCi/L, and 27.4% reached 4 pCi/L. Tennessee as a whole (70 Tennessee counties, pooled) comes to 24.9%: 2.5 points lower than here.
Among its state's counties it ranks 4th of 15 Tennessee counties with 30 or more tests for the same period. Statewide for the same period, Blount County reported the highest share (50.0%) and Hamilton County the lowest (2.4%).
Below the action level, 69 tests (47.3%) came in under 2 pCi/L, against 49.4% statewide, and 37 tests (25.3%) fell between 2 and 4, against 25.7% statewide. The busiest year on file was 2022, with 1,551 tests reported; the quietest, 2023, had 146.
EPA's 1993 zone map puts Davidson County in Zone 1, a predicted county average above 4 pCi/L. USGS geology rates 100% of the county's land high radon potential.
Next door, the shares run from 2.4% in Wilson County to 20.0% in Sumner County, with Sumner County, Rutherford County and Williamson County below Davidson County.
CDC also counts 55 tests taken after mitigation in Davidson County for the same period: tests in homes where a fix was already in.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Davidson County, Geology
The ground under Davidson County
PredictedUSGS's geologic map puts all of Davidson County's mapped land in one class: high radon potential. The map puts 86.7% of Davidson County in the area it calls Nashville Basin and 13.3% in Cherty Highland. USGS gives the first a radon index of 14 and the second 12, both in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Nashville Basin | Mississippian Limestone. | High | 14 | 86.7% |
| Cherty Highland | Cherty dolostone. | High | 12 | 13.3% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Davidson County beside the ground around it
Davidson County has more high-potential ground than Tennessee as a whole: 100% of its land against 47.2%. Of the 6 counties that border it, none has as large a share of high-potential ground; Rutherford County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Davidson County, Local resources
Radon testing and mitigation in Davidson 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
Davidson County, Questions
Questions about radon in Davidson County
Are radon levels high in Davidson County?
In 2023, 27.4% of the radon tests reported to CDC for Davidson County, Tennessee were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.2 pCi/L. Of 15 Tennessee counties with 30 or more tests for the same period, 3 reported a higher share; pooled, the state comes to 24.9%.
Which counties border Davidson County?
Davidson County borders 6 counties: Cheatham County, Robertson County, Williamson County, Sumner County, Wilson County and Rutherford County.
Products
Davidson County, Products
Testing a home in Davidson County
In Davidson County, 27.4% of 146 tests reported to CDC in 2023 reached 4 pCi/L, against 24.9% pooled across Tennessee. In Zone 1 the year-round level in Davidson 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
MonitorX-Sense
XR0A-SR battery digital radon detector with a screen
- C-NRPP 2024/25: Not included
- Battery
- Screen
Method: Alpha spectrometry
First reading: Within 24 hours
Short-term kit
RA100 short-term liquid scintillation radon test kit
- Lab fee extra
Method: Liquid scintillation
In home: 48 to 96 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Davidson County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Davidson County
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Davidson County, Bordering counties
Counties bordering Davidson County
Calculated by Radon411- Radon levels in Cheatham CountyEPA zone 2
28.6%at or above 4 pCi/L
Median 3.3 pCi/L · 7 tests · 1.2 points above Davidson County
- Radon levels in Sumner CountyEPA zone 2
20.0%at or above 4 pCi/L
Median 1.4 pCi/L · 30 tests · 7.4 points below Davidson County
- Radon levels in Rutherford CountyEPA zone 1
20.0%at or above 4 pCi/L
Median 1.6 pCi/L · 50 tests · 7.4 points below Davidson County
- Radon levels in Williamson CountyEPA zone 1
16.5%at or above 4 pCi/L
Median 1.3 pCi/L · 115 tests · 10.9 points below Davidson County
- Radon levels in Robertson CountyEPA zone 2
7.1%at or above 4 pCi/L
Median 0.8 pCi/L · 14 tests · 20.3 points below Davidson County
- Radon levels in Wilson CountyEPA zone 1
2.4%at or above 4 pCi/L
Median 0.9 pCi/L · 82 tests · 25.0 points below Davidson County
Davidson County, Cities and towns
Cities and towns in Davidson County
The Census Bureau estimates 745,904 residents in Davidson County for July 1, 2025, 29,751 more than in 2020 (+4.2%). Packed into its land, that is 1,481 people per square mile. Nashville-Davidson alone is home to 721,074 of them, 96.7% of the total. Reported testing is thin here: 146 tests over 2023, or 0.2 for every 1,000 residents (2025 estimate), where Tennessee as a whole comes to 0.3.
From Nashville-Davidson to Berry Hill, CDC publishes no figure by town: each reads Davidson County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Nashville-Davidson | 721,074 | +4.5% | 96.7% |
| Goodlettsvilleextends beyond Davidson County | 17,506 | −1.6% | Counted whole |
| Oak Hill | 4,581 | −6.1% | 0.6% |
| Forest Hills | 4,473 | −10.8% | 0.6% |
| Belle Meade | 2,621 | −9.6% | 0.4% |
| Ridgetopextends beyond Davidson County | 2,156 | +2.1% | Counted whole |
| Berry Hill | 1,864 | −11.2% | 0.2% |
Places in Davidson County with a city page: 1 of 1
7 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 Davidson County is counted whole, so it has no share.
Davidson County, Homes
Homes in Davidson County
Davidson County has 345,026 homes, and many share a building: 33% are in buildings of five or more, 50% are detached houses, against 68% across Tennessee. Half of its homes were built before 1985, close to Tennessee's 1986: 19% date from before 1960 and 32% from 2000 or later. 53% 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 | Davidson County | Tennessee |
|---|---|---|
| Housing units | 345,026 | 3,095,472 |
| Detached houses | 50% | 68% |
| In buildings of 5 or more | 33% | 14% |
| Mobile homes | 1% | 8% |
| Built before 1960 | 19% | 18% |
| Built since 2000 | 32% | 29% |
| Middle year built | 1985 | 1986 |
| Owner-occupied | 53% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.