Short-term kit
Radon Short Term Test Kit short-term charcoal radon test kit, lab fee included
- Lab fee included
Method: Charcoal
In home: 2 to 7 days
Locations and reports
Radon Levels in Sebastian County, Arkansas
EPA puts Sebastian County in Zone 3, its lowest radon zone, and only 22 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
14.3%
Washington County, 54 miles
- Washington
- 14.3%
- Arkansas
- 22.7%
Share at 4+ pCi/L, 56 tests, 2007 to 2016
Ground above low
None
21.3 pts below Arkansas
- Sebastian
- 0.0%
- Arkansas
- 21.3%
Share of land USGS rates moderate or high potential
Tests reported
29
Too few for a share
- Sebastian
- 29
- Needed
- 30
2007 to 2016, laboratory
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 Sebastian 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
Sebastian County, At a glance
Sebastian 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
Radon tests reported for Sebastian County, 2008 to 2017, laboratory
CDC holds 22 reported tests for Sebastian County over the 2008 to 2017 laboratory totals, with a median of 0.2 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Sebastian County beside the counties around it is how this page reads it.
What these figures count
Only 22 tests were reported to CDC for Sebastian 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).
Sebastian County, Compared
Sebastian County radon figures, compared
Calculated by Radon411CDC's largest figure for Sebastian County rests on 29 tests over the 2007 to 2016 laboratory totals, 1 of them at or above 4 pCi/L, so each test moves its share by 3.4 points and no rank or comparison is drawn from it. Results reached as high as 4.3 pCi/L, with a middle value of 0.1 pCi/L.
The nearest counties with a figure are Washington County (54 miles away) at 14.3%, Garland County (77 miles away) at 45.8% and Benton County (79 miles away) at 31.0%. Pooled across 60 Arkansas counties, 22.7% of reported tests reached that level; across every county in the country with a figure, 35.8%.
Statewide for the same period, Garland County reported the highest share (45.8%) and Pulaski County the lowest (6.8%). EPA's 1993 map puts Sebastian 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.
Sebastian County, Geology
The ground under Sebastian County
PredictedUSGS's geologic map puts all of Sebastian County's mapped land in one class: low radon potential. 99.1% of it lies in the area the map calls Arkansas Valley, to which USGS gives a radon index of 8, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Arkansas Valley | Mississippian and Pennsylvanian sandstones and shales. | Low | 8 | 99.1% |
| Athens Plateau/Fourche Mountains | Mississippian and Pennsylvanian sandstones and shales. | Low | 8 | 0.7% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Sebastian County beside the ground around it
Across Arkansas 21.3% of the land is rated moderate; none of Sebastian County's is. Of the 6 counties that border it, 1 has more moderate-potential ground, Sequoyah County, OK the most at 2.6%.
The map rates the ground, not the air in any home.
Local help
Sebastian County, Local resources
Radon testing and mitigation in Sebastian County
- Arkansas's radon programArkansas Department of HealthArkansas's radon program answers questions about testing, mitigation and the rules in Arkansas.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsAsk the program whether it has free or discounted kits, or compare kits you can buy.
- Compare kits
- See the Arkansas directoryNo professionals are listed in Arkansas yet. The state program can point you to registered testers and mitigators.
What Arkansas's program says
- Phone
- 501-661-2621
- ADH.EPI.Radon@arkansas.gov
What it means
Sebastian County, Questions
Questions about radon in Sebastian County
Are radon levels high in Sebastian County?
Over the 2008 to 2017 laboratory totals, 4.5% of the radon tests reported to CDC for Sebastian County, Arkansas were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.2 pCi/L. Of the 5 nearest counties with a figure, within 115 miles, the share of tests at or above 4 pCi/L runs from 6.8% to 45.8%.
Which counties border Sebastian County?
Sebastian County borders 6 counties: Scott County, AR, Crawford County, AR, Le Flore County, OK, Franklin County, AR, Logan County, AR and Sequoyah County, OK.
Products
Sebastian County, Products
Testing a home in Sebastian County
No CDC figure names Sebastian County; the nearest county with one, Washington County (54 miles away), reported 14.3% 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 Sebastian 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
Monitor
Corentium Home battery digital radon detector
- C-NRPP 2024/25: Approved
- Battery
- Screen
Method: Alpha spectrometry
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Sebastian County, Bordering counties
Counties bordering Sebastian County
Calculated by Radon411- Radon levels in Logan County, AREPA zone 3
20.0%at or above 4 pCi/L
Median 2.1 pCi/L · 5 tests
- Radon levels in Crawford County, AREPA zone 3
12.5%at or above 4 pCi/L
Median 0.7 pCi/L · 8 tests
- Radon levels in Le Flore County, OKEPA zone 3
0.0%at or above 4 pCi/L
Median 0.8 pCi/L · 9 tests
- Radon levels in Franklin County, AREPA zone 3
0.0%at or above 4 pCi/L
Median 0.1 pCi/L · 1 test
- Radon levels in Sequoyah County, OKEPA zone 2
0.0%at or above 4 pCi/L
Median 1.6 pCi/L · 4 tests
- Radon levels in Scott County, AREPA zone 3
No CDC figure for 2007 to 2016; its page reads it against its own neighbours.
Sebastian County, Cities and towns
Cities and towns in Sebastian County
The Census Bureau estimates 130,641 residents in Sebastian County for July 1, 2025, 2,834 more than in 2020 (+2.2%). That works out to 246 people per square mile of land. Fort Smith alone is home to 90,855 of them, 69.5% of the total. CDC's 29 reported tests for 2007 to 2016 work out to 0.2 per 1,000 residents (2025 estimate), close to Arkansas' 0.2.
From Fort Smith to Midland, CDC publishes no figure by town: each reads Sebastian County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Fort Smith | 90,855 | +1.9% | 69.5% |
| Greenwood | 9,793 | +2.7% | 7.5% |
| Barling | 5,452 | +13.8% | 4.2% |
| Lavaca | 2,528 | +3.3% | 1.9% |
| Mansfieldextends beyond Sebastian County | 1,066 | +1.8% | Counted whole |
| Hackett | 857 | +9.5% | 0.7% |
| Bonanza | 603 | +3.1% | 0.5% |
| Hartford | 499 | −0.6% | 0.4% |
| Huntington | 486 | −0.6% | 0.4% |
| Central City | 469 | +0.4% | 0.4% |
| Midland | 224 | −0.4% | 0.2% |
11 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 Sebastian County is counted whole, so it has no share.
Sebastian County, Homes
Homes in Sebastian County
Of Sebastian County's 57,197 homes, 70% are detached houses, against 70% across Arkansas; 12% are in buildings of five or more homes. Half of its homes were built before 1980, close to Arkansas' 1987: 22% date from before 1960 and 22% from 2000 or later. 61% of occupied homes are lived in by their owner (Arkansas: 66%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Sebastian County | Arkansas |
|---|---|---|
| Housing units | 57,197 | 1,382,664 |
| Detached houses | 70% | 70% |
| In buildings of 5 or more | 12% | 10% |
| Mobile homes | 4% | 11% |
| Built before 1960 | 22% | 14% |
| Built since 2000 | 22% | 28% |
| Middle year built | 1980 | 1987 |
| Owner-occupied | 61% | 66% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.