Short-term kitFirst Alert
RD1 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 2 to 4 days
Locations and reports
Radon Levels in Galveston County, Texas
EPA puts Galveston County in Zone 3, its lowest radon zone, and most reported tests there come back low, though 0.0% of 73 (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
0.0%
10.2 pts below TX
- Galveston
- 0.0%
- Texas
- 10.2%
73 tests, 2008 to 2017
Median result
0.2pCi/L
Below action level
- Galveston
- 0.2 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
73
15th of 22 by tests
- Galveston
- 73
- 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
19 of 22
Lowest quarter
- Galveston
- 0.0%
- Randall
- 69.0%
By share, of 22 with 30+ tests
Read a result for Galveston County
Starts at Galveston County's median, 0.2 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 0.2 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. Galveston County's median reported result, 2008 to 2017.
The data
Galveston County, At a glance
Galveston County at a glance
Predicted: EPA radon zone
EPA Zone 3: lower predicted potential
USGS geologic potential: Low across 84% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Galveston County, 2008 to 2017, laboratory
Under 2 pCi/L: 100%2 to 4 pCi/L: 0%4 pCi/L and above: 0%
Of 73 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 73 | 100.0% |
| 2 to 4 pCi/L | 0 | 0.0% |
| 4 pCi/L and above | 0 | 0.0% |
What these figures count
These are the 73 tests reported to CDC for Galveston 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).
Galveston County, Compared
Galveston County radon figures, compared
Calculated by Radon411Only 0 of 73 radon tests reported for Galveston County over the 2008 to 2017 laboratory totals reached 4 pCi/L (0.0%). The median result, 0.2 pCi/L, sits below 2, well under EPA's 4 pCi/L action level, and the top reported result was 0.9 pCi/L.
Across 138 Texas counties pooled together, 10.2% of tests reached that level, so Galveston County runs 10.2 points below its state. Against the national pool of 35.7%, the gap is 35.7 points lower. Its place in the state: 19th of 22 Texas counties with 30 or more tests for the same period.
Zone 3 on EPA's map (predicted average under 2 pCi/L) and a 0.0% share point the same way here. Of 2 neighbours with a figure, all 2 reported a larger share at or above 4 pCi/L; the spread is 2.9% (Harris County) to 6.3% (Brazoria County).
Below the action level, 73 tests (100.0%) came in under 2 pCi/L, against 80.3% statewide, and 0 tests (0.0%) fell between 2 and 4, against 9.6% statewide. USGS geology rates 84% of the county's land low radon potential.
CDC's ten-year totals for Galveston County went from 59 tests (2005 to 2014) to 73 (2008 to 2017), the share going from 0.0% to 0.0%.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Galveston County, Geology
The ground under Galveston County
PredictedUSGS's geologic map puts all of Galveston County's mapped land in one class: low radon potential. 84.4% of it lies in the area the map calls Coastal 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 |
|---|---|---|---|---|
| Coastal Plain | Cretaceous through Quaternary marine sandstone, shale, chalk, limestone, siltstone, clay, and lignite. | Low | 7 | 84.4% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Galveston County beside the ground around it
Across Texas 0.5% of the land is rated high; none of Galveston County's is. None of the 3 counties that border it has any moderate-potential ground either.
The map rates the ground, not the air in any home.
Local help
Galveston County, Local resources
Radon testing and mitigation in Galveston 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
Galveston County, Questions
Questions about radon in Galveston County
Are radon levels high in Galveston County?
Over the 2008 to 2017 laboratory totals, 0.0% of the radon tests reported to CDC for Galveston County, Texas were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.2 pCi/L. Of 22 Texas counties with 30 or more tests for the same period, 18 reported a higher share; pooled, the state comes to 10.2%.
Which counties border Galveston County?
Galveston County borders 3 counties: Brazoria County, Harris County and Chambers County.
Products
Galveston County, Products
Testing a home in Galveston County
In Galveston County, 0.0% of 73 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 Galveston 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
MonitorPYZYCKYH
RD17 plug-in radon detector with a rechargeable battery and color screen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
First reading: Within 6 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Galveston County, Bordering counties
Counties bordering Galveston County
Calculated by Radon411- Radon levels in Brazoria CountyEPA zone 3
6.3%at or above 4 pCi/L
Median 0.3 pCi/L · 32 tests · 6.3 points above Galveston County
- Radon levels in Harris CountyEPA zone 3
2.9%at or above 4 pCi/L
Median 0.4 pCi/L · 733 tests · 2.9 points above Galveston County
- Radon levels in Chambers CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.1 pCi/L · 3 tests · 0.0 points above Galveston County
Galveston County, Cities and towns
Cities and towns in Galveston County
Galveston County is growing: the Census Bureau puts it at 372,207 residents on July 1, 2025, up 5.9% from 351,586 in 2020. That works out to 981 people per square mile of land. League City, the largest place on its list (119,905 residents in all), extends beyond Galveston County, so no share of the total is worked out for it. CDC's 73 reported tests for 2008 to 2017 work out to 0.2 per 1,000 residents (2025 estimate), close to Texas' 0.1.
From League City to Jamaica Beach, CDC publishes no figure by town: each reads Galveston County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| League Cityextends beyond Galveston County | 119,905 | +4.6% | Counted whole |
| Texas Cityextends beyond Galveston County | 59,733 | +14.3% | Counted whole |
| Galveston | 53,636 | Level | 14.4% |
| Friendswoodextends beyond Galveston County | 41,319 | +0.7% | Counted whole |
| Dickinson | 21,908 | +2.1% | 5.9% |
| La Marque | 20,324 | +10.1% | 5.5% |
| Seabrookextends beyond Galveston County | 13,974 | +2.9% | Counted whole |
| Santa Fe | 13,913 | +9.3% | 3.7% |
| Hitchcock | 7,722 | +5.6% | 2.1% |
| Kemah | 3,097 | +70.9% | 0.8% |
| Bayou Vista | 1,755 | −0.4% | 0.5% |
| Clear Lake Shores | 1,298 | +1.0% | 0.3% |
- Tiki Island
- Jamaica Beach
14 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. “(part)” marks a place that extends into another county. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025). A place that extends beyond Galveston County is counted whole, so it has no share.
Galveston County, Homes
Homes in Galveston County
Of Galveston County's 159,379 homes, 72% are detached houses, against 65% across Texas; 18% are in buildings of five or more homes. Half of its homes were built before 1989, close to Texas' 1990: 13% date from before 1960 and 37% from 2000 or later. 67% 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 | Galveston County | Texas |
|---|---|---|
| Housing units | 159,379 | 11,890,808 |
| Detached houses | 72% | 65% |
| In buildings of 5 or more | 18% | 21% |
| Mobile homes | 4% | 7% |
| Built before 1960 | 13% | 13% |
| Built since 2000 | 37% | 37% |
| Middle year built | 1989 | 1990 |
| Owner-occupied | 67% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.