Short-term kitempowerDX
Standard Radon Test short-term mail-in radon test kit
- Lab fee included
Method: Passive sampler
In home: 48 to 96 hours
Locations and reports
Radon Levels in Duval County, Texas
EPA puts Duval County in Zone 3, its lowest radon zone. Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Nearest county
0.0%
Nueces County, 55 miles
- Nueces
- 0.0%
- Texas
- 10.4%
Share at 4+ pCi/L, 45 tests, 2007 to 2016
Ground above low
None
27.3 pts below Texas
- Duval
- 0.0%
- Texas
- 27.3%
Share of land USGS rates moderate or high potential
Tests reported
0
None published
A home here needs its own test
EPA radon zone
Zone 3
Lower potential
- 1
- 2
- Zone 3
1 highest, 3 lowest
EPA predicts under 2 pCi/L indoors
Read a result for Duval County
Starts at EPA's action level
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 4.0 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.
The data
Duval County, At a glance
Duval 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
No CDC test figures here
CDC has published no radon test figures for Duval County. Nueces County, 55 miles away, is the nearest county with a figure over the 2007 to 2016 laboratory totals.
Duval County, Compared
Duval County radon figures, compared
Calculated by Radon411CDC's county radon counts over the 2007 to 2016 laboratory totals cover 140 Texas counties, and Duval County is not among them: no year's figure and no ten-year laboratory total names it. Pooled across 140 Texas counties, 10.4% of reported tests reached that level; across every county in the country with a figure, 35.8%.
The nearest counties with a figure are Nueces County (55 miles away) at 0.0%, Bexar County (122 miles away) at 6.6% and Travis County (188 miles away) at 9.3%. Statewide for the same period, Randall County reported the highest share (71.4%) and Nueces County the lowest (0.0%).
EPA's 1993 map puts Duval County in Zone 3, its lowest label: a predicted county average under 2 pCi/L. USGS geology rates 100% of the county's land low radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Duval County, Geology
The ground under Duval County
PredictedUSGS's geologic map puts all of Duval County's mapped land in one class: low radon potential. All of it lies in the area the map calls South Texas Plain, to which USGS gives a radon index of 7, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| South Texas Plain | Cretaceous through Quaternary marine sandstone, shale, chalk, limestone, siltstone, clay, and lignite. | Low | 7 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Duval County beside the ground around it
Across Texas 0.5% of the land is rated high; none of Duval 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
Duval County, Local resources
Radon testing and mitigation in Duval 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
Duval County, Questions
Questions about radon in Duval County
Are radon levels high in Duval County?
No CDC testing statistics are published here for Duval County, Texas yet. Of the 8 nearest counties with a figure, within 241 miles, the share of tests at or above 4 pCi/L runs from 0.0% to 14.3%.
Which counties border Duval County?
Duval County borders 7 counties: Jim Wells County, Jim Hogg County, Webb County, McMullen County, Live Oak County, Brooks County and La Salle County.
Products
Duval County, Products
Testing a home in Duval County
No CDC figure names Duval County; the nearest county with one, Nueces County (55 miles away), reported 0.0% of its tests at or above 4 pCi/L over the 2007 to 2016 laboratory totals, the only reading nearby until a test of this home. 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 Duval County.
Test kits and monitors3
See every kit and monitor
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
Monitor
Corentium Home 2 battery digital radon monitor
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- Screen, app
Method: Alpha spectrometry
Readings: Every 60 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Duval County, Bordering counties
Counties bordering Duval County
Calculated by Radon411- Radon levels in Jim Wells CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.1 pCi/L · 1 test
- Radon levels in Webb CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.6 pCi/L · 6 tests
- Radon levels in Jim Hogg CountyEPA zone 3
No CDC figure for 2007 to 2016; its page reads it against its own neighbours.
- Radon levels in McMullen CountyEPA zone 3
No CDC figure for 2007 to 2016; its page reads it against its own neighbours.
- Radon levels in Live Oak CountyEPA zone 3
No CDC figure for 2007 to 2016; its page reads it against its own neighbours.
- Radon levels in Brooks CountyEPA zone 3
No CDC figure for 2007 to 2016; its page reads it against its own neighbours.
- Radon levels in La Salle CountyEPA zone 3
No CDC figure for 2007 to 2016; its page reads it against its own neighbours.
Duval County, Cities and towns
Cities and towns in Duval County
About 9,402 people live in Duval County by the Census Bureau's estimate for July 1, 2025, 409 fewer than in 2020 (−4.2%). Spread over its land, that is 5.2 people to the square mile. San Diego, the largest place on its list (3,503 residents in all), extends beyond Duval County, so no share of the total is worked out for it. CDC publishes no radon test count for Duval County; across Texas its counts for 2007 to 2016 come to 0.1 tests for every 1,000 residents (2025 estimate).
From San Diego to Benavides, CDC publishes no figure by town: each reads Duval County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| San Diegoextends beyond Duval County | 3,503 | −6.3% | Counted whole |
| Freer | 2,308 | −6.8% | 24.5% |
| Benavides | 1,099 | −7.2% | 11.7% |
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). A place that extends beyond Duval County is counted whole, so it has no share.
Duval County, Homes
Homes in Duval County
Duval County is a place of houses on their own lots: 84% of its 4,430 homes are detached single-family houses, against 65% across Texas. The homes are older than Texas' as a whole: half were built before 1977 (1990 for Texas), and 26% date from before 1960. 71% 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 | Duval County | Texas |
|---|---|---|
| Housing units | 4,430 | 11,890,808 |
| Detached houses | 84% | 65% |
| In buildings of 5 or more | 3% | 21% |
| Mobile homes | 11% | 7% |
| Built before 1960 | 26% | 13% |
| Built since 2000 | 13% | 37% |
| Middle year built | 1977 | 1990 |
| Owner-occupied | 71% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.