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 Barnstable County, Massachusetts
EPA puts Barnstable County in Zone 2, its middle radon zone, and 20.6% of its 6,521 reported radon tests (2008 to 2017, laboratory totals) were at or above 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
20.6%
3.2 pts below MA
- Barnstable
- 20.6%
- MA
- 23.8%
6,521 tests, 2008 to 2017
Median result
2.0pCi/L
Below action level
- Barnstable
- 2.0 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
6,521
8th of 14 by tests
- Barnstable
- 6,521
- Middlesex
- 75,220
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
EPA predicts 2 to 4 pCi/L indoors
Rank in MA
8 of 14
Middle half
- Barnstable
- 20.6%
- Worcester
- 33.5%
By share, of 14 with 30+ tests
Read a result for Barnstable County
Starts at Barnstable County's median, 2.0 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.0 pCi/L
Between 2 and 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is between 2 and 4 pCi/L. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Barnstable County's median reported result, 2008 to 2017.
The data
Barnstable County, At a glance
Barnstable County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Barnstable County is a
USGS geologic potential: Moderate across 91% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Barnstable County, 2008 to 2017, laboratory
Under 2 pCi/L: 48%2 to 4 pCi/L: 31%4 pCi/L and above: 21%
Of 6,521 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 3,157 | 48.4% |
| 2 to 4 pCi/L | 2,022 | 31.0% |
| 4 pCi/L and above | 1,342 | 20.6% |
What these figures count
These are the 6,521 tests reported to CDC for Barnstable 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).
Barnstable County, Compared
Barnstable County radon figures, compared
Calculated by Radon411Barnstable County's 6,521 reported tests over the 2008 to 2017 laboratory totals had a middle value of 2.0 pCi/L and a maximum of 36.3 pCi/L, and 20.6% reached 4 pCi/L. Massachusetts as a whole (14 Massachusetts counties, pooled) comes to 23.8%: 3.2 points higher than here.
Among its state's counties it ranks 8th of 14 Massachusetts counties with 30 or more tests for the same period. Statewide for the same period, Worcester County reported the highest share (33.5%) and Nantucket County the lowest (5.0%).
Below the action level, 3,157 tests (48.4%) came in under 2 pCi/L, against 49.6% statewide, and 2,022 tests (31.0%) fell between 2 and 4, against 26.6% statewide. CDC's ten-year totals for Barnstable County went from 6,178 tests (2005 to 2014) to 6,521 (2008 to 2017), the share going from 20.6% to 20.6%.
EPA's 1993 zone map puts Barnstable County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 91% of the county's land moderate radon potential.
Next door, the shares run from 17.0% in Plymouth County to 17.4% in Dukes County, with Dukes County and Plymouth County below Barnstable County.
CDC also counts 23 tests taken after mitigation in Barnstable County for the same period: tests in homes where a fix was already in.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Barnstable County, Geology
The ground under Barnstable County
PredictedUSGS's geologic map puts all of Barnstable County's mapped land in one class: moderate radon potential. 91.3% of it lies in the area the map calls Esmond-Dedham terrane, to which USGS gives a radon index of 11, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Esmond-Dedham terrane | Granite plutons, mafic metasedimentary and metavolcanic rocks. | Moderate | 11 | 91.3% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Barnstable County beside the ground around it
Across Massachusetts 31.9% of the land is rated high; none of Barnstable County's is. Of the 2 counties that border it, 1 has more moderate-potential ground, Plymouth County the most at 97.8%.
The map rates the ground, not the air in any home.
Local help
Barnstable County, Local resources
Radon testing and mitigation in Barnstable County
- Radon UnitRadon Unit, run by Department of Public Health, answers questions about testing, mitigation and the rules in Massachusetts.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
- Professionals in Massachusetts5 professionals are listed in Massachusetts.
What Massachusetts's program says
- Phone
- (800) 723-6695
- DPHIAQ.radon@mass.gov
What it means
Barnstable County, Questions
Questions about radon in Barnstable County
Are radon levels high in Barnstable County?
Over the 2008 to 2017 laboratory totals, 20.6% of the radon tests reported to CDC for Barnstable County, Massachusetts were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.0 pCi/L. Of 14 Massachusetts counties with 30 or more tests for the same period, 7 reported a higher share; pooled, the state comes to 23.8%.
Which counties border Barnstable County?
Barnstable County borders 2 counties: Dukes County and Plymouth County.
Products
Barnstable County, Products
Testing a home in Barnstable County
In Barnstable County, 20.6% of 6,521 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 23.8% pooled across Massachusetts. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Barnstable County; a long-term test tells the year-round average.
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
EcoBlu plug-in digital radon monitor with a display
- C-NRPP 2024/25: Not included
- Plug-in
- Alarm
- Screen
Method: Ion chamber
First reading: Within 10 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Barnstable County, Bordering counties
Counties bordering Barnstable County
Calculated by Radon411- Radon levels in Dukes CountyEPA zone 2
17.4%at or above 4 pCi/L
Median 1.7 pCi/L · 317 tests · 3.2 points below Barnstable County
- Radon levels in Plymouth CountyEPA zone 2
17.0%at or above 4 pCi/L
Median 1.7 pCi/L · 16,320 tests · 3.6 points below Barnstable County
Barnstable County, Cities and towns
Cities and towns in Barnstable County
The Census Bureau estimates 233,539 residents in Barnstable County for July 1, 2025, 5,484 more than in 2020 (+2.4%). That works out to 592 people per square mile of land. Barnstable Town, its one incorporated place, has 50,101 residents, 21.5% of the total. CDC's 6,521 reported tests for 2008 to 2017 work out to 27.9 per 1,000 residents (2025 estimate), close to Massachusetts' 32.7.
Barnstable Town is the one incorporated place here; CDC publishes no figure by town, so it reads Barnstable County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Barnstable Town | 50,101 | +2.5% | 21.5% |
One incorporated place, 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).
Barnstable County, Homes
Homes in Barnstable County
Barnstable County is a place of houses on their own lots: 82% of its 165,661 homes are detached single-family houses, against 51% across Massachusetts. Much of Barnstable County is recent building: 12% of its homes have gone up since 2000 and the middle year built is 1976, against 1963 for Massachusetts. Owners live in 81% of the occupied homes (Massachusetts: 63%), so for most households a test and a fix are their own to order.
| Homes | Barnstable County | Massachusetts |
|---|---|---|
| Housing units | 165,661 | 3,014,657 |
| Detached houses | 82% | 51% |
| In buildings of 5 or more | 7% | 22% |
| Mobile homes | 1% | 1% |
| Built before 1960 | 25% | 47% |
| Built since 2000 | 12% | 14% |
| Middle year built | 1976 | 1963 |
| Owner-occupied | 81% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.