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
Locations and reports
Radon Levels in Essex County, Massachusetts
EPA puts Essex County in Zone 1, its highest radon zone, and 28.7% of its 20,398 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
28.7%
4.9 pts above MA
- Essex
- 28.7%
- MA
- 23.8%
20,398 tests, 2008 to 2017
Median result
2.2pCi/L
Below action level
- Essex
- 2.2 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
20,398
4th of 14 by tests
- Essex
- 20,398
- Middlesex
- 75,220
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in MA
2 of 14
Top quarter
- Essex
- 28.7%
- Worcester
- 33.5%
By share, of 14 with 30+ tests
Read a result for Essex County
Starts at Essex County's median, 2.2 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.2 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. Essex County's median reported result, 2008 to 2017.
The data
Essex County, At a glance
Essex County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Essex County in
USGS geologic potential: High across 87% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Essex County, 2008 to 2017, laboratory
Under 2 pCi/L: 45%2 to 4 pCi/L: 26%4 pCi/L and above: 29%
Of 20,398 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 9,123 | 44.7% |
| 2 to 4 pCi/L | 5,425 | 26.6% |
| 4 pCi/L and above | 5,850 | 28.7% |
What these figures count
These are the 20,398 tests reported to CDC for Essex 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).
Essex County, Compared
Essex County radon figures, compared
Calculated by Radon411Essex County's 20,398 reported tests over the 2008 to 2017 laboratory totals had a middle value of 2.2 pCi/L and a maximum of 192.0 pCi/L, and 28.7% reached 4 pCi/L. Massachusetts as a whole (14 Massachusetts counties, pooled) comes to 23.8%: 4.9 points lower than here.
Among its state's counties it ranks 2nd 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, 9,123 tests (44.7%) came in under 2 pCi/L, against 49.6% statewide, and 5,425 tests (26.6%) fell between 2 and 4, against 26.6% statewide. CDC's ten-year totals for Essex County went from 20,284 tests (2005 to 2014) to 20,398 (2008 to 2017), the share going from 28.1% to 28.7%.
EPA's 1993 zone map puts Essex County in Zone 1, a predicted county average above 4 pCi/L. USGS geology rates 87% of the county's land high radon potential.
Next door, the shares run from 10.4% in Suffolk County to 41.9% in Rockingham County, NH, with Middlesex County and Suffolk County below Essex County.
CDC also counts 248 tests taken after mitigation in Essex 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.
Essex County, Geology
The ground under Essex County
PredictedMost of the ground under Essex County is one class on USGS's geologic map: 86.7% of its land is high radon potential, with 9.0% moderate and 0.7% low. The map puts 33.7% of Essex County in the area it calls Cape Ann and Peabody plutons and 27.3% in Nashoba and Rhode Island Terranes, with 3 smaller areas beside them. USGS gives both a radon index of 13, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Cape Ann and Peabody plutons | Felsic granitic rocks and lesser exposures of mafic plutonic rocks. | High | 13 | 33.7% |
| Nashoba and Rhode Island Terranes | Granitic plutonic rocks and metamorphic rocks. | High | 13 | 27.3% |
| Merrimack Belt | Granitic plutons, metasedimentary rocks (phyllites, carbonaceous slates and schists). | High | 14 | 25.7% |
| Newbury Basin | Rhyolite, andesite, tuff, basalt, siltstone, mudstone. | Moderate | 10 | 8.9% |
| Boston Basin | Proterozoic to Pennsylvanian sedimentary rocks. | 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.
Essex County beside the ground around it
Essex County has more high-potential ground than Massachusetts as a whole: 86.7% of its land against 31.9%. Of the 4 counties that border it, none has as large a share of high-potential ground; Middlesex County comes nearest at 82.6%.
The map rates the ground, not the air in any home.
Local help
Essex County, Local resources
Radon testing and mitigation in Essex 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
Essex County, Questions
Questions about radon in Essex County
Are radon levels high in Essex County?
Over the 2008 to 2017 laboratory totals, 28.7% of the radon tests reported to CDC for Essex County, Massachusetts were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.2 pCi/L. Of 14 Massachusetts counties with 30 or more tests for the same period, 1 reported a higher share; pooled, the state comes to 23.8%.
Which counties border Essex County?
Essex County borders 4 counties: Suffolk County, MA, Middlesex County, MA, Rockingham County, NH and Hillsborough County, NH.
Products
Essex County, Products
Testing a home in Essex County
In Essex County, 28.7% of 20,398 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 23.8% pooled across Massachusetts. In Zone 1 the year-round level in Essex County is the one to know: a long-term test (more than 90 days) or a monitor, with a short-term kit for a first answer.
Test kits and monitors3
See every kit and monitor
Monitor
Hello Radon C battery radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Screen
Method: Alpha spectrometry
First reading: Within 24 hours
Short-term kitFirst Alert
RD1 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 2 to 4 days
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Essex County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Essex County
Explore
Essex County, Bordering counties
Counties bordering Essex County
Calculated by Radon411- Radon levels in Rockingham County, NHEPA zone 2
41.9%at or above 4 pCi/L
Median 3.1 pCi/L · 4,077 tests · 13.2 points above Essex County
- Radon levels in Hillsborough County, NHEPA zone 2
34.4%at or above 4 pCi/L
Median 2.5 pCi/L · 5,528 tests · 5.7 points above Essex 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 · 6.7 points below Essex 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 · 18.3 points below Essex County
Essex County, Cities and towns
Cities and towns in Essex County
The Census Bureau estimates 826,653 residents in Essex County for July 1, 2025, 18,854 more than in 2020 (+2.3%). Packed into its land, that is 1,678 people per square mile. No town dominates: Lynn, the largest, has 104,236 residents, 12.6% of the total. CDC's 20,398 reported tests for 2008 to 2017 work out to 24.7 per 1,000 residents (2025 estimate), close to Massachusetts' 32.7.
From Lynn to Methuen Town, CDC publishes no figure by town: each reads Essex County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Lynn | 104,236 | +3.1% | 12.6% |
| Lawrence | 89,320 | +0.5% | 10.8% |
| Haverhill | 68,361 | +1.1% | 8.3% |
| Peabody | 55,953 | +2.9% | 6.8% |
| Salem | 45,381 | +3.9% | 5.5% |
| Beverly | 43,363 | +1.9% | 5.2% |
| Gloucester | 30,627 | +3.0% | 3.7% |
| Newburyport | 19,148 | +4.7% | 2.3% |
- Amesbury Town
- Methuen Town
10 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).
Essex County, Homes
Homes in Essex County
Fewer than six in ten of Essex County's 328,460 homes are detached houses (50%, against 51% across Massachusetts); the rest are attached, in shared buildings or mobile. Half of its homes were built before 1960, close to Massachusetts' 1963: 50% date from before 1960 and 12% from 2000 or later. 64% 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 | Essex County | Massachusetts |
|---|---|---|
| Housing units | 328,460 | 3,014,657 |
| Detached houses | 50% | 51% |
| In buildings of 5 or more | 21% | 22% |
| Mobile homes | 1% | 1% |
| Built before 1960 | 50% | 47% |
| Built since 2000 | 12% | 14% |
| Middle year built | 1960 | 1963 |
| Owner-occupied | 64% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.