Skip to content

Locations and reports

Radon Levels in La Salle County, Texas

EPA puts La Salle 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

    6.6%

    Bexar County, 84 miles

    Bexar
    6.6%
    Texas
    10.4%

    Share at 4+ pCi/L, 197 tests, 2007 to 2016

  • Ground above low

    None

    27.3 pts below Texas

    La Salle
    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. 1
    2. 2
    3. Zone 3

    1 highest, 3 lowest

    EPA predicts under 2 pCi/L indoors

Read a result for La Salle County

Starts at EPA's action level

4.0pCi/L

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

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 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

La Salle County, At a glance

La Salle County at a glance

Predicted: EPA radon zone

EPA Zone 3: lower predicted potential

is EPA's lowest class, and its forecast for La Salle County as a whole is an average indoor of less than 2 pCi/L (less than 75 Bq/m³). A low zone clears no address in it: homes above EPA's turn up in all three zones.

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 La Salle County. Bexar County, 84 miles away, is the nearest county with a figure over the 2007 to 2016 laboratory totals.

How to read these figures

La Salle County, Compared

La Salle County radon figures, compared

Calculated by Radon411

CDC's county radon counts over the 2007 to 2016 laboratory totals cover 140 Texas counties, and La Salle 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 Bexar County (84 miles away) at 6.6%, Nueces County (100 miles away) at 0.0% and Travis County (158 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 La Salle 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.

Texas, the United States and the counties around La Salle County, 2007 to 2016, laboratory
AreaTestsAt or above 4 pCi/LMedian
Texas, pooled140 counties, pooled4,54810.4%Not pooled
United States, pooled2,666 counties, pooled1,939,02535.8%Not pooled
Randall Countyhighest in the state8471.4%6.2 pCi/L
Nueces Countylowest in the state450.0%0.6 pCi/L
Atascosa County, TXborders it10.0%1.1 pCi/L
Webb County, TXborders it60.0%0.6 pCi/L
The nearest Texas counties to La Salle County with 30 or more tests, 2007 to 2016, laboratory
CountyDistanceTestsAt or above 4 pCi/LMedian
Bexar County84 mi1976.6%0.6 pCi/L
Nueces County100 mi450.0%0.6 pCi/L
Travis County158 mi4089.3%0.8 pCi/L
Williamson County183 mi982.0%0.7 pCi/L
Bell County210 mi3514.3%1.1 pCi/L
Fort Bend County217 mi1173.4%0.2 pCi/L
Brazoria County229 mi326.3%0.3 pCi/L
Brazos County232 mi490.0%0.2 pCi/L

Pooled shares: Radon411's sum of CDC's county counts for one period.

La Salle County, Geology

The ground under La Salle County

Predicted

USGS's geologic map puts all of La Salle 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).

USGS's geologic areas under La Salle County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
South Texas PlainCretaceous through Quaternary marine sandstone, shale, chalk, limestone, siltstone, clay, and lignite.Low7100%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

La Salle County beside the ground around it

Across Texas 0.5% of the land is rated high; none of La Salle County's is. None of the 6 counties that border it has any moderate-potential ground either.

Share of land by USGS radon potential: La Salle County, the 6 counties bordering it and Texas
AreaEPA zoneLow potentialModerate potentialHigh potential
La Salle CountyZone 3100%NoneNone
Frio CountyZone 3100%NoneNone
McMullen CountyZone 3100%NoneNone
Dimmit CountyZone 3100%NoneNone
Atascosa CountyZone 3100%NoneNone
Webb CountyZone 399.9%NoneNone
Duval CountyZone 3100%NoneNone
Texas254 counties, pooled by land areaVaries72.4%26.8%0.5%

The map rates the ground, not the air in any home.

Local help

La Salle County, Local resources

Radon testing and mitigation in La Salle County

What it means

La Salle County, Questions

Questions about radon in La Salle County

Are radon levels high in La Salle County?

No CDC testing statistics are published here for La Salle County, Texas yet. Of the 8 nearest counties with a figure, within 232 miles, the share of tests at or above 4 pCi/L runs from 0.0% to 14.3%.

Which counties border La Salle County?

La Salle County borders 6 counties: Frio County, McMullen County, Dimmit County, Atascosa County, Webb County and Duval County.

Products

La Salle County, Products

Testing a home in La Salle County

No CDC figure names La Salle County; the nearest county with one, Bexar County (84 miles away), reported 6.6% 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 La Salle County.

Test kits and monitors3

See every kit and monitor

Best radon monitors for La Salle County homes, compared

Explore

La Salle County, Bordering counties

Counties bordering La Salle County

Calculated by Radon411

La Salle County, Cities and towns

Cities and towns in La Salle County

About 6,517 people live in La Salle County by the Census Bureau's estimate for July 1, 2025, 125 fewer than in 2020 (−1.9%). Spread over its land, that is 4.4 people to the square mile. Cotulla alone is home to 3,583 of them, 55.0% of the total. Together its 2 incorporated places hold 63.3% of those residents; the other 36.7% live outside any of them. CDC publishes no radon test count for La Salle County; across Texas its counts for 2007 to 2016 come to 0.1 tests for every 1,000 residents (2025 estimate).

From Cotulla to Encinal, CDC publishes no figure by town: each reads La Salle County's.

The cities and towns in La Salle County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Cotulla3,583−3.6%55.0%
Encinal543+1.1%8.3%

2 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).

La Salle County, Homes

Homes in La Salle County

Of La Salle County's 2,307 homes, 67% are detached houses, against 65% across Texas; 22% are mobile homes. The homes are older than Texas' as a whole: half were built before 1981 (1990 for Texas), and 34% date from before 1960. Owners live in 79% of the occupied homes (Texas: 63%), so for most households a test and a fix are their own to order.

Homes in La Salle County, Texas, 2019 to 2023
HomesLa Salle CountyTexas
Housing units2,30711,890,808
Detached houses67%65%
In buildings of 5 or more8%21%
Mobile homes22%7%
Built before 196034%13%
Built since 200027%37%
Middle year built19811990
Owner-occupied79%63%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.