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 Marlboro County, South Carolina
EPA puts Marlboro County in Zone 3, its lowest radon zone, and only 7 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
Highest bordering
3.8%
Robeson County
- Robeson
- 3.8%
- Richmond
- 0.0%
4 of 8 neighbours have 30+ tests, 2008 to 2017
Nearest county
0.0%
Florence County, 40 miles
- Florence
- 0.0%
- SC
- 19.4%
Share at 4+ pCi/L, 59 tests, 2008 to 2017
Ground above low
None
18.5 pts below SC
- Marlboro
- 0.0%
- SC
- 18.5%
Share of land USGS rates moderate or high potential
Tests reported
8
Too few for a share
- Marlboro
- 8
- 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 Marlboro 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
Marlboro County, At a glance
Marlboro 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 Marlboro County, 2008 to 2017, laboratory
CDC holds 7 reported tests for Marlboro County over the 2008 to 2017 laboratory totals, with a median of 0.9 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Marlboro County beside the counties around it is how this page reads it.
What these figures count
Only 7 tests were reported to CDC for Marlboro 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).
Marlboro County, Compared
Marlboro County radon figures, compared
Calculated by Radon411CDC's largest figure for Marlboro County rests on 8 tests over the 2007 to 2016 laboratory totals, 0 of them at or above 4 pCi/L, so each test moves its share by 12.5 points and no rank or comparison is drawn from it. Results reached as high as 1.7 pCi/L, with a middle value of 0.9 pCi/L.
Of the counties bordering it, 4 have a figure over the 2008 to 2017 laboratory totals: Robeson County, NC reported the largest share at or above 4 pCi/L, 3.8%, and Richmond County, NC the smallest, 0.0%, with Scotland County, NC at 3.2% and Florence County at 0.0% between. Farther out, Kershaw County (55 miles away) at 5.0%, Lancaster County (59 miles away) at 13.6% and Horry County (61 miles away) at 0.9% have figures too. Pooled across 46 South Carolina counties, 19.4% of reported tests reached that level; across every county in the country with a figure, 35.7%.
Statewide for the same period, Oconee County reported the highest share (42.6%) and Florence County the lowest (0.0%). EPA's 1993 map puts Marlboro 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.
Marlboro County, Geology
The ground under Marlboro County
PredictedUSGS's geologic map puts all of Marlboro County's mapped land in one class: low radon potential. All of it lies in the area the map calls Upper and Middle Coastal Plain, 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 |
|---|---|---|---|---|
| Upper and Middle Coastal Plain | Tertiary coastal plain sandy and silty sediments and marsh deposits. | Low | 8 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Marlboro County beside the ground around it
Across South Carolina 0.2% of the land is rated high; none of Marlboro County's is. Of the 8 counties that border it, 3 have more moderate-potential ground, Anson County, NC the most at 31.1%.
The map rates the ground, not the air in any home.
Local help
Marlboro County, Local resources
Radon testing and mitigation in Marlboro County
- South Carolina Radon ProgramSouth Carolina Radon Program, run by South Carolina Department of Environmental Services, offers free or discounted test kits, and answers questions about testing and mitigation in South Carolina.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
The South Carolina Radon Program offers free short-term radon test kits to South Carolina homeowners, subject to availability.
- Compare kits
- Professionals in South Carolina2 professionals are listed in South Carolina.
What South Carolina's program says
- Phone
- 1-800-768-0362
- radon@des.sc.gov
What it means
Marlboro County, Questions
Questions about radon in Marlboro County
Are radon levels high in Marlboro County?
Over the 2008 to 2017 laboratory totals, 0.0% of the radon tests reported to CDC for Marlboro County, South Carolina were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.9 pCi/L. Of the counties bordering it, 4 have a figure over the 2008 to 2017 laboratory totals: Robeson County, NC reported the largest share at or above 4 pCi/L, 3.8%, and Richmond County, NC the smallest, 0.0%, with Scotland County, NC at 3.2% and Florence County at 0.0% between.
Which counties border Marlboro County?
Marlboro County borders 8 counties: Scotland County, NC, Dillon County, SC, Darlington County, SC, Chesterfield County, SC, Robeson County, NC, Richmond County, NC, Florence County, SC and Anson County, NC.
Products
Marlboro County, Products
Testing a home in Marlboro County
No CDC figure names Marlboro County; the nearest county with one, Florence County (40 miles away), reported 0.0% of its tests at or above 4 pCi/L over the 2008 to 2017 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 Marlboro 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
EcoQube Flex battery digital radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- Alarm
- Screen, app
Method: Ion chamber
First reading: Within 15 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Marlboro County, Bordering counties
Counties bordering Marlboro County
Calculated by Radon411- Radon levels in Robeson County, NCEPA zone 3
3.8%at or above 4 pCi/L
Median 0.8 pCi/L · 53 tests
- Radon levels in Scotland County, NCEPA zone 3
3.2%at or above 4 pCi/L
Median 1.0 pCi/L · 31 tests
- Radon levels in Dillon County, SCEPA zone 3
0.0%at or above 4 pCi/L
Median 0.3 pCi/L · 18 tests
- Radon levels in Darlington County, SCEPA zone 3
0.0%at or above 4 pCi/L
Median 0.6 pCi/L · 28 tests
- Radon levels in Chesterfield County, SCEPA zone 3
0.0%at or above 4 pCi/L
Median 0.6 pCi/L · 10 tests
- Radon levels in Richmond County, NCEPA zone 3
0.0%at or above 4 pCi/L
Median 0.6 pCi/L · 52 tests
- Radon levels in Florence County, SCEPA zone 3
0.0%at or above 4 pCi/L
Median 0.7 pCi/L · 59 tests
- Radon levels in Anson County, NCEPA zone 3
0.0%at or above 4 pCi/L
Median 0.6 pCi/L · 18 tests
Marlboro County, Cities and towns
Cities and towns in Marlboro County
About 25,488 people live in Marlboro County by the Census Bureau's estimate for July 1, 2025, 1,006 fewer than in 2020 (−3.8%). That works out to 53 people per square mile of land. Its largest town, Bennettsville, has 7,565 residents, 29.7% of the total. Together its 5 incorporated places hold 40.4% of those residents; the other 59.6% live outside any of them. Reported testing is thin here: 8 tests over 2007 to 2016, or 0.3 for every 1,000 residents (2025 estimate), where South Carolina as a whole comes to 4.6.
From Bennettsville to Tatum, CDC publishes no figure by town: each reads Marlboro County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Bennettsville | 7,565 | −4.9% | 29.7% |
| McColl | 1,974 | −4.2% | 7.7% |
| Clio | 577 | −4.3% | 2.3% |
| Blenheim | 107 | −5.3% | 0.4% |
| Tatum | 70 | −5.4% | 0.3% |
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).
Marlboro County, Homes
Homes in Marlboro County
Of Marlboro County's 12,059 homes, 62% are detached houses, against 64% across South Carolina; 30% are mobile homes. The homes are older than South Carolina's as a whole: half were built before 1978 (1991 for South Carolina), and 23% date from before 1960. 63% of occupied homes are lived in by their owner (South Carolina: 71%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Marlboro County | South Carolina |
|---|---|---|
| Housing units | 12,059 | 2,401,638 |
| Detached houses | 62% | 64% |
| In buildings of 5 or more | 3% | 13% |
| Mobile homes | 30% | 15% |
| Built before 1960 | 23% | 13% |
| Built since 2000 | 13% | 35% |
| Middle year built | 1978 | 1991 |
| Owner-occupied | 63% | 71% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.