Short-term kit
Air Chek Short-Term radon test kit you hang, lab fee included
- Lab fee included
In home: 72 to 168 hours
Locations and reports
Radon Levels in Smith County, Texas
EPA puts Smith County in Zone 3, its lowest radon zone, and most reported tests there come back low, though 5.8% of 52 (2008 to 2017, laboratory totals) reached 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
5.8%
4.4 pts below TX
- Smith
- 5.8%
- Texas
- 10.2%
52 tests, 2008 to 2017
Median result
0.8pCi/L
Below action level
- Smith
- 0.8 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
52
17th of 22 by tests
- Smith
- 52
- Harris
- 733
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 3
Lower potential
- 1
- 2
- Zone 3
1 highest, 3 lowest
EPA predicts under 2 pCi/L indoors
Rank in Texas
13 of 22
Middle half
- Smith
- 5.8%
- Randall
- 69.0%
By share, of 22 with 30+ tests
Read a result for Smith County
Starts at Smith County's median, 0.8 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 0.8 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. Smith County's median reported result, 2008 to 2017.
The data
Smith County, At a glance
Smith County at a glance
Predicted: EPA radon zone
EPA Zone 3: lower predicted potential
USGS geologic potential: Low across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Smith County, 2008 to 2017, laboratory
Under 2 pCi/L: 92%2 to 4 pCi/L: 2%4 pCi/L and above: 6%
Of 52 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 48 | 92.3% |
| 2 to 4 pCi/L | 1 | 1.9% |
| 4 pCi/L and above | 3 | 5.8% |
What these figures count
These are the 52 tests reported to CDC for Smith 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).
Smith County, Compared
Smith County radon figures, compared
Calculated by Radon411Smith County reports fewer high tests than Texas overall. 5.8% of its 52 tests over the 2008 to 2017 laboratory totals were at or above 4 pCi/L. That is 4.4 points below the 10.2% pooled from 138 Texas counties.
Ordered from highest share down, it comes 13th of 22 Texas counties with 30 or more tests for the same period. Nationally, every county with a figure for the same period pools to 35.7%; Smith County sits 29.9 points below it.
Zone 3 on EPA's map (predicted average under 2 pCi/L) and a 5.8% share point the same way here.
Half the tests came in under 0.8 pCi/L and half over it; the single highest reached 62.9 pCi/L. The rest split 92.3% under 2 pCi/L and 1.9% from 2 to 4 (Texas: 80.3% and 9.6%).
CDC's ten-year totals for Smith County went from 35 tests (2005 to 2014) to 52 (2008 to 2017), the share going from 8.6% to 5.8%.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Smith County, Geology
The ground under Smith County
PredictedUSGS's geologic map puts all of Smith County's mapped land in one class: low radon potential. All of it lies in the area the map calls East Texas Province, to which USGS gives a radon index of 6, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| East Texas Province | Cretaceous through Quaternary marine sandstone, shale, chalk, limestone, siltstone, clay, and lignite. | Low | 6 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Smith County beside the ground around it
Across Texas 0.5% of the land is rated high; none of Smith County's is. None of the 7 counties that border it has any moderate-potential ground either.
The map rates the ground, not the air in any home.
Local help
Smith County, Local resources
Radon testing and mitigation in Smith County
- Texas Radon GroupTexas Radon Group, run by Texas Tech University, does not license radon professionals and offers free or discounted test kits, and answers questions about testing and mitigation in Texas.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
The Texas Radon Group offers free radon test kits for Texas individuals who qualify.
- Compare kits
- Professionals in Texas7 professionals are listed in Texas.
What Texas's program says
- Licensing of radon professionals
There are no radon certification requirements for the State of Texas at this time, but the National Radon Proficiency Program lists radon testers and mitigators within Texas that have passed a rigorous national certification program.
What it means
Smith County, Questions
Questions about radon in Smith County
Are radon levels high in Smith County?
Over the 2008 to 2017 laboratory totals, 5.8% of the radon tests reported to CDC for Smith County, Texas were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.8 pCi/L. Of 22 Texas counties with 30 or more tests for the same period, 12 reported a higher share; pooled, the state comes to 10.2%.
Which counties border Smith County?
Smith County borders 7 counties: Gregg County, Wood County, Upshur County, Van Zandt County, Rusk County, Henderson County and Cherokee County.
Products
Smith County, Products
Testing a home in Smith County
In Smith County, 5.8% of 52 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 10.2% pooled across Texas. Zone 3 is the lowest label, yet homes at or above 4 pCi/L occur in every zone: a short-term kit (2 to 90 days) is the quick first check in Smith County.
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
RM-63Pro rechargeable radon monitor with a touchscreen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Smith County, Bordering counties
Counties bordering Smith County
Calculated by Radon411- Radon levels in Gregg CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.9 pCi/L · 13 tests · 5.8 points below Smith County
- Radon levels in Upshur CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.9 pCi/L · 6 tests · 5.8 points below Smith County
- Radon levels in Van Zandt CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.1 pCi/L · 5 tests · 5.8 points below Smith County
- Radon levels in Rusk CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.4 pCi/L · 2 tests · 5.8 points below Smith County
- Radon levels in Henderson CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.8 pCi/L · 1 test · 5.8 points below Smith County
- Radon levels in Cherokee CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.1 pCi/L · 1 test · 5.8 points below Smith County
- Radon levels in Wood CountyEPA zone 3
No CDC figure for 2008 to 2017; its page reads it against its own neighbours.
Smith County, Cities and towns
Cities and towns in Smith County
Smith County is growing: the Census Bureau puts it at 252,549 residents on July 1, 2025, up 7.8% from 234,205 in 2020. That works out to 274 people per square mile of land. Its largest town, Tyler, has 113,723 residents, 45.0% of the total. CDC's 52 reported tests for 2008 to 2017 work out to 0.2 per 1,000 residents (2025 estimate), close to Texas' 0.1.
From Tyler to New Chapel Hill, CDC publishes no figure by town: each reads Smith County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Tyler | 113,723 | +7.1% | 45.0% |
| Whitehouse | 9,970 | +20.3% | 3.9% |
| Lindale | 7,385 | +22.0% | 2.9% |
| Bullardextends beyond Smith County | 5,301 | +37.8% | Counted whole |
| Hideaway | 3,459 | +7.7% | 1.4% |
| Overtonextends beyond Smith County | 2,315 | +1.8% | Counted whole |
| Troupextends beyond Smith County | 2,188 | +8.8% | Counted whole |
| Arp | 1,020 | +12.7% | 0.4% |
| Noonday | 781 | +28.2% | 0.3% |
| Winona | 747 | +18.8% | 0.3% |
| New Chapel Hill | 651 | +6.0% | 0.3% |
11 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 Smith County is counted whole, so it has no share.
Smith County, Homes
Homes in Smith County
Of Smith County's 98,672 homes, 69% are detached houses, against 65% across Texas; 12% are in buildings of five or more homes. Half of its homes were built before 1986, close to Texas' 1990: 18% date from before 1960 and 32% from 2000 or later. 69% of occupied homes are lived in by their owner (Texas: 63%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Smith County | Texas |
|---|---|---|
| Housing units | 98,672 | 11,890,808 |
| Detached houses | 69% | 65% |
| In buildings of 5 or more | 12% | 21% |
| Mobile homes | 11% | 7% |
| Built before 1960 | 18% | 13% |
| Built since 2000 | 32% | 37% |
| Middle year built | 1986 | 1990 |
| Owner-occupied | 69% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.