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Radon Levels in Cameron County, Texas

EPA puts Cameron County in Zone 3, its lowest radon zone, and only 27 radon tests from it are on file with CDC (2008 to 2017, laboratory totals). Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

How to test this homeFind a certified tester

  • Nearest county

    0.0%

    Nueces County, 110 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

    Cameron
    0.0%
    Texas
    27.3%

    Share of land USGS rates moderate or high potential

  • Tests reported

    27

    Too few for a share

    Cameron
    27
    Needed
    30

    2008 to 2017, laboratory

  • 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 Cameron 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.

Interpret this readingWhat a fix costs

The data

Cameron County, At a glance

Cameron County at a glance

Predicted: EPA radon zone

EPA Zone 3: lower predicted potential

is EPA's lowest class, and its forecast for Cameron 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 92% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Cameron County, 2008 to 2017, laboratory

CDC holds 27 reported tests for Cameron County over the 2008 to 2017 laboratory totals, with a median of 0.7 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Cameron County beside the counties around it is how this page reads it.

What these figures count

Only 27 tests were reported to CDC for Cameron County over 2008 to 2017 (laboratory totals), 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: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).

How to read these figures

Cameron County, Compared

Cameron County radon figures, compared

Calculated by Radon411

CDC's largest figure for Cameron County rests on 27 tests over the 2008 to 2017 laboratory totals, 0 of them at or above 4 pCi/L, so each test moves its share by 3.7 points and no rank or comparison is drawn from it. Results reached as high as 3.8 pCi/L, with a middle value of 0.7 pCi/L.

The nearest counties with a figure are Nueces County (110 miles away) at 0.0%, Bexar County (236 miles away) at 6.6% and Brazoria County (246 miles away) at 6.3%. Pooled across 140 Texas counties, 10.4% of reported tests reached that level; across every county in the country with a figure, 35.8%.

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 Cameron County in Zone 3, its lowest label: a predicted county average under 2 pCi/L. USGS geology rates 92% of the county's land low radon potential.

Texas, the United States and the counties around Cameron 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
Hidalgo County, TXborders it150.0%0.8 pCi/L
The nearest Texas counties to Cameron County with 30 or more tests, 2007 to 2016, laboratory
CountyDistanceTestsAt or above 4 pCi/LMedian
Nueces County110 mi450.0%0.6 pCi/L
Bexar County236 mi1976.6%0.6 pCi/L
Brazoria County246 mi326.3%0.3 pCi/L
Fort Bend County257 mi1173.4%0.2 pCi/L
Galveston County274 mi830.0%0.2 pCi/L
Harris County287 mi7753.1%0.2 pCi/L
Travis County290 mi4089.3%0.8 pCi/L
Williamson County311 mi982.0%0.7 pCi/L
Cameron County ten-year laboratory totals, against Texas' pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestTexas, pooledChange from the row before
2008 to 2017270.0%0.7 pCi/L3.8 pCi/L10.2%Level
2007 to 2016270.0%0.7 pCi/L3.8 pCi/L10.4%Level
2006 to 2015210.0%0.7 pCi/L1.6 pCi/L11.0%Level
2005 to 2014210.0%0.7 pCi/L1.6 pCi/L10.6%First on file

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

Cameron County, Geology

The ground under Cameron County

Predicted

USGS's geologic map puts all of Cameron County's mapped land in one class: low radon potential. 91.5% 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 Cameron County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
South Texas PlainCretaceous through Quaternary marine sandstone, shale, chalk, limestone, siltstone, clay, and lignite.Low791.5%

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

Cameron County beside the ground around it

Across Texas 0.5% of the land is rated high; none of Cameron County's is. None of the 2 counties that border it has any moderate-potential ground either.

Share of land by USGS radon potential: Cameron County, the 2 counties bordering it and Texas
AreaEPA zoneLow potentialModerate potentialHigh potential
Cameron CountyZone 391.5%NoneNone
Willacy CountyZone 392.8%NoneNone
Hidalgo CountyZone 399.8%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

Cameron County, Local resources

Radon testing and mitigation in Cameron County

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

Cameron County, Questions

Questions about radon in Cameron County

Are radon levels high in Cameron County?

Over the 2008 to 2017 laboratory totals, 0.0% of the radon tests reported to CDC for Cameron County, Texas were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.7 pCi/L. Of the 8 nearest counties with a figure, within 311 miles, the share of tests at or above 4 pCi/L runs from 0.0% to 9.3%.

Which counties border Cameron County?

Cameron County borders 2 counties: Willacy County and Hidalgo County.

Products

Cameron County, Products

Testing a home in Cameron County

No CDC figure names Cameron County; the nearest county with one, Nueces County (110 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 Cameron County.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Cameron County homes, compared

Explore

Cameron County, Bordering counties

Counties bordering Cameron County

Calculated by Radon411

Cameron County, Cities and towns

Cities and towns in Cameron County

The Census Bureau estimates 433,946 residents in Cameron County for July 1, 2025, 12,442 more than in 2020 (+3.0%). That works out to 487 people per square mile of land. Its largest town, Brownsville, has 192,957 residents, 44.5% of the total. Together its 17 incorporated places hold 77.8% of those residents; the other 22.2% live outside any of them. Reported testing is thin here: 27 tests over 2008 to 2017, or 0.1 for every 1,000 residents (2025 estimate), where Texas as a whole comes to 0.1.

From Brownsville to Bayview, CDC publishes no figure by town: each reads Cameron County's.

The 12 largest cities and towns in Cameron County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Brownsville192,957+3.4%44.5%
Harlingen72,467+0.8%16.7%
San Benito24,980+0.1%5.8%
Los Fresnos8,703+6.7%2.0%
La Feria7,222+5.2%1.7%
Primera5,478+3.8%1.3%
Port Isabel5,302+5.4%1.2%
Laguna Vista3,780+6.9%0.9%
Combes3,255+3.4%0.8%
Rancho Viejo2,851+0.7%0.7%
Santa Rosa2,355−4.1%0.5%
Rio Hondo2,332+14.7%0.5%
  • South Padre Island
  • Palm Valley
  • Los Indios
  • Indian Lake
  • Bayview

17 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).

Cameron County, Homes

Homes in Cameron County

Of Cameron County's 157,565 homes, 64% are detached houses, against 65% across Texas; 14% are in buildings of five or more homes. Half of its homes were built before 1992, close to Texas' 1990: 10% date from before 1960 and 36% from 2000 or later. 65% 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 in Cameron County, Texas, 2019 to 2023
HomesCameron CountyTexas
Housing units157,56511,890,808
Detached houses64%65%
In buildings of 5 or more14%21%
Mobile homes11%7%
Built before 196010%13%
Built since 200036%37%
Middle year built19921990
Owner-occupied65%63%

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