Short-term kitKidde
442020 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 3 days
Locations and reports
Radon Levels in Norfolk County, Massachusetts
EPA puts Norfolk County in Zone 2, its middle radon zone, and 21.2% of its 39,205 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
21.2%
2.6 pts below MA
- Norfolk
- 21.2%
- MA
- 23.8%
39,205 tests, 2008 to 2017
Median result
1.8pCi/L
Below action level
- Norfolk
- 1.8 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
39,205
3rd of 14 by tests
- Norfolk
- 39,205
- 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
7 of 14
Middle half
- Norfolk
- 21.2%
- Worcester
- 33.5%
By share, of 14 with 30+ tests
Read a result for Norfolk County
Starts at Norfolk County's median, 1.8 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 1.8 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. Norfolk County's median reported result, 2008 to 2017.
The data
Norfolk County, At a glance
Norfolk County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Norfolk County is a
USGS geologic potential: Moderate across 80% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Norfolk County, 2008 to 2017, laboratory
Under 2 pCi/L: 53%2 to 4 pCi/L: 26%4 pCi/L and above: 21%
Of 39,205 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 20,661 | 52.7% |
| 2 to 4 pCi/L | 10,251 | 26.1% |
| 4 pCi/L and above | 8,293 | 21.2% |
What these figures count
These are the 39,205 tests reported to CDC for Norfolk 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).
Norfolk County, Compared
Norfolk County radon figures, compared
Calculated by Radon411Norfolk County's 39,205 reported tests over the 2008 to 2017 laboratory totals had a middle value of 1.8 pCi/L and a maximum of 171.5 pCi/L, and 21.2% reached 4 pCi/L. Massachusetts as a whole (14 Massachusetts counties, pooled) comes to 23.8%: 2.6 points higher than here.
Among its state's counties it ranks 7th 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, 20,661 tests (52.7%) came in under 2 pCi/L, against 49.6% statewide, and 10,251 tests (26.1%) fell between 2 and 4, against 26.6% statewide. CDC's ten-year totals for Norfolk County went from 37,865 tests (2005 to 2014) to 39,205 (2008 to 2017), the share going from 20.3% to 21.2%.
EPA's 1993 zone map puts Norfolk County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 80% of the county's land moderate radon potential.
Next door, the shares run from 10.4% in Suffolk County to 33.5% in Worcester County, with Plymouth County, Providence County, RI and Suffolk County below Norfolk County.
CDC also counts 214 tests taken after mitigation in Norfolk 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.
Norfolk County, Geology
The ground under Norfolk County
PredictedMost of the ground under Norfolk County is one class on USGS's geologic map: 80.3% of its land is moderate radon potential, with 7.0% high and 11.6% low. The map puts 76.2% of Norfolk County in the area it calls Esmond-Dedham terrane and 11.6% in Boston Basin, with 2 smaller areas beside them. USGS gives the first a radon index of 11, in the moderate band (9 to 11), and the second 8, in the low band (5 to 8).
| 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 | 76.2% |
| Boston Basin | Proterozoic to Pennsylvanian sedimentary rocks. | Low | 8 | 11.6% |
| Nashoba and Rhode Island Terranes | Granitic plutonic rocks and metamorphic rocks. | High | 13 | 7.0% |
| Narrangansett Basin | Pennsylvanian sedimentary rocks. | Moderate | 9 | 4.1% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Norfolk County beside the ground around it
Massachusetts as a whole has more high-potential ground than Norfolk County: 31.9% of its land, against 7.0% here. Of the 6 counties that border it, 3 have more high-potential ground, Worcester County the most at 85.4%.
The map rates the ground, not the air in any home.
Local help
Norfolk County, Local resources
Radon testing and mitigation in Norfolk 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
Norfolk County, Questions
Questions about radon in Norfolk County
Are radon levels high in Norfolk County?
Over the 2008 to 2017 laboratory totals, 21.2% of the radon tests reported to CDC for Norfolk County, Massachusetts were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.8 pCi/L. Of 14 Massachusetts counties with 30 or more tests for the same period, 6 reported a higher share; pooled, the state comes to 23.8%.
Which counties border Norfolk County?
Norfolk County borders 6 counties: Suffolk County, MA, Middlesex County, MA, Plymouth County, MA, Bristol County, MA, Providence County, RI and Worcester County, MA.
Products
Norfolk County, Products
Testing a home in Norfolk County
In Norfolk County, 21.2% of 39,205 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 Norfolk County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL416 long-term radon test kit, lab fee included
- Lab fee included
Method: Alpha track
In home: 90 days to 12 months
MonitorAEGTEST
HOUND-1085 palm-sized rechargeable radon detector
- 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
Norfolk County, Bordering counties
Counties bordering Norfolk County
Calculated by Radon411- Radon levels in Worcester County, MAEPA zone 1
33.5%at or above 4 pCi/L
Median 2.6 pCi/L · 46,440 tests · 12.3 points above Norfolk County
- Radon levels in Bristol County, MAEPA zone 2
23.2%at or above 4 pCi/L
Median 2.0 pCi/L · 13,358 tests · 2.0 points above Norfolk County
- Radon levels in Middlesex County, MAEPA zone 1
22.0%at or above 4 pCi/L
Median 1.9 pCi/L · 75,220 tests · 0.8 points above Norfolk County
- Radon levels in Plymouth County, MAEPA zone 2
17.0%at or above 4 pCi/L
Median 1.7 pCi/L · 16,320 tests · 4.2 points below Norfolk County
- Radon levels in Providence County, RIEPA zone 2
16.8%at or above 4 pCi/L
Median 1.6 pCi/L · 17,655 tests · 4.4 points below Norfolk County
- Radon levels in Suffolk County, MAEPA zone 3
10.4%at or above 4 pCi/L
Median 1.3 pCi/L · 8,525 tests · 10.8 points below Norfolk County
Norfolk County, Cities and towns
Cities and towns in Norfolk County
The Census Bureau estimates 739,749 residents in Norfolk County for July 1, 2025, 16,102 more than in 2020 (+2.2%). Packed into its land, that is 1,868 people per square mile. No town dominates: Quincy, the largest, has 103,173 residents, 13.9% of the total. Together its 5 incorporated places hold 36.6% of those residents; the other 63.4% live outside any of them. Testing is reported here more often than across the state: CDC's 39,205 reported tests for 2008 to 2017 come to 53.0 for every 1,000 residents (2025 estimate), against 32.7 for Massachusetts.
From Quincy to Franklin Town, CDC publishes no figure by town: each reads Norfolk County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Quincy | 103,173 | +1.7% | 13.9% |
| Weymouth Town | 59,759 | +4.0% | 8.1% |
| Braintree Town | 38,957 | −0.3% | 5.3% |
| Randolph Town | 34,948 | −0.1% | 4.7% |
| Franklin Town | 33,955 | +5.0% | 4.6% |
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).
Norfolk County, Homes
Homes in Norfolk County
Of Norfolk County's 293,420 homes, 57% are detached houses, against 51% across Massachusetts; 25% are in buildings of five or more homes. Half of its homes were built before 1964, close to Massachusetts' 1963: 46% date from before 1960 and 15% from 2000 or later. 69% of occupied homes are lived in by their owner (Massachusetts: 63%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Norfolk County | Massachusetts |
|---|---|---|
| Housing units | 293,420 | 3,014,657 |
| Detached houses | 57% | 51% |
| In buildings of 5 or more | 25% | 22% |
| Mobile homes | under 1% | 1% |
| Built before 1960 | 46% | 47% |
| Built since 2000 | 15% | 14% |
| Middle year built | 1964 | 1963 |
| Owner-occupied | 69% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.