
Short-term kitKidde
442020 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 3 days
Locations and reports
EPA puts Hardin County in Zone 3, its lowest radon zone, and only 6 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
Nearest county
7.1%
Montgomery County, 67 miles
Share at 4+ pCi/L, 85 tests, 2007 to 2016
Ground above low
None
27.3 pts below Texas
Share of land USGS rates moderate or high potential
Tests reported
7
Too few for a share
2007 to 2016, laboratory
EPA radon zone
Zone 3
Lower potential
1 highest, 3 lowest
EPA predicts under 2 pCi/L indoors
Read a result for Hardin County
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
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
Hardin County, At a glance
Predicted: EPA radon zone
USGS geologic potential: Low across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
CDC holds 6 reported tests for Hardin County over the 2008 to 2017 laboratory totals, with a median of 0.8 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Hardin County beside the counties around it is how this page reads it.
Only 6 tests were reported to CDC for Hardin 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).
Hardin County, Compared
CDC's largest figure for Hardin County rests on 7 tests over the 2007 to 2016 laboratory totals, 0 of them at or above 4 pCi/L, so each test moves its share by 14.3 points and no rank or comparison is drawn from it. Results reached as high as 1.1 pCi/L, with a middle value of 0.7 pCi/L.
The nearest counties with a figure are Montgomery County (67 miles away) at 7.1%, Harris County (68 miles away) at 3.1% and Galveston County (73 miles away) at 0.0%. 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 Hardin 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.
Hardin County, Geology
USGS's geologic map puts all of Hardin County's mapped land in one class: low radon potential. All 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 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Across Texas 0.5% of the land is rated high; none of Hardin County's is. None of the 6 counties that border it has any moderate-potential ground either.
The map rates the ground, not the air in any home.
Local help
Hardin County, Local resources
The Texas Radon Group offers free radon test kits for Texas individuals who qualify.
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
Hardin County, Questions
Over the 2008 to 2017 laboratory totals, 0.0% of the radon tests reported to CDC for Hardin County, Texas were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.8 pCi/L. Of the 8 nearest counties with a figure, within 187 miles, the share of tests at or above 4 pCi/L runs from 0.0% to 17.1%.
Hardin County borders 6 counties: Liberty County, Tyler County, Jefferson County, Orange County, Jasper County and Polk County.
Products
Hardin County, Products
No CDC figure names Hardin County; the nearest county with one, Montgomery County (67 miles away), reported 7.1% 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 Hardin County.
Test kits and monitors: 1 of 3
Explore
Hardin County, Bordering counties
100.0%at or above 4 pCi/L
Median 25.5 pCi/L · 1 test
4.8%at or above 4 pCi/L
Median 0.1 pCi/L · 21 tests
0.0%at or above 4 pCi/L
Median 1.2 pCi/L · 1 test
0.0%at or above 4 pCi/L
Median 0.8 pCi/L · 11 tests
0.0%at or above 4 pCi/L
Median 0.1 pCi/L · 2 tests
No CDC figure for 2007 to 2016; its page reads it against its own neighbours.
Hardin County, Cities and towns
The Census Bureau estimates 58,723 residents in Hardin County for July 1, 2025, 2,366 more than in 2020 (+4.2%). That works out to 66 people per square mile of land. Its largest town, Lumberton, has 14,123 residents, 24.1% of the total. Together its 5 incorporated places hold 42.6% of those residents; the other 57.4% live outside any of them. CDC's 7 reported tests for 2007 to 2016 work out to 0.1 per 1,000 residents (2025 estimate), close to Texas' 0.1.
From Lumberton to Rose Hill Acres, CDC publishes no figure by town: each reads Hardin County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Lumberton | 14,123 | +3.6% | 24.1% |
| Silsbee | 6,613 | −4.3% | 11.3% |
| Kountze | 2,127 | +8.5% | 3.6% |
| Sour Lake | 1,841 | +3.6% | 3.1% |
| Rose Hill Acres | 329 | +1.5% | 0.6% |
5 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).
Hardin County, Homes
Of Hardin County's 24,686 homes, 70% are detached houses, against 65% across Texas; 23% are mobile homes. Half of its homes were built before 1992, close to Texas' 1990: 11% date from before 1960 and 38% from 2000 or later. Owners live in 83% of the occupied homes (Texas: 63%), so for most households a test and a fix are their own to order.
| Homes | Hardin County | Texas |
|---|---|---|
| Housing units | 24,686 | 11,890,808 |
| Detached houses | 70% | 65% |
| In buildings of 5 or more | 5% | 21% |
| Mobile homes | 23% | 7% |
| Built before 1960 | 11% | 13% |
| Built since 2000 | 38% | 37% |
| Middle year built | 1992 | 1990 |
| Owner-occupied | 83% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.