Short-term kit
RA100 short-term liquid scintillation radon test kit
- Lab fee extra
Method: Liquid scintillation
In home: 48 to 96 hours
Locations and reports
Radon Levels in Essex County, New Jersey
EPA puts Essex County in Zone 2, its middle radon zone, and most reported tests there come back low, though 4.1% of 8,341 (2022) reached 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
4.1%
5.6 pts below NJ
- Essex
- 4.1%
- New Jersey
- 9.7%
8,341 tests, 2022
Median result
0.7pCi/L
Below action level
- Essex
- 0.7 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2022
Tests reported
8,341
5th of 21 by tests
- Essex
- 8,341
- Bergen
- 11,440
Reported to CDC before any fix, 2022
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 New Jersey
17 of 21
Lowest quarter
- Essex
- 4.1%
- Warren
- 24.6%
By share, of 21 with 30+ tests
Read a result for Essex County
Starts at Essex County's median, 0.7 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 0.7 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. Essex County's median reported result, 2022.
The data
Essex County, At a glance
Essex County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Essex County is a
USGS geologic potential: Low across 99% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Essex County, 2022
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 5.4% |
| 2015 | 5.5% |
| 2016 | 4.8% |
| 2017 | 4.7% |
| 2018 | 3.9% |
| 2019 | 4.6% |
| 2020 | 5.7% |
| 2021 | 4.3% |
| 2022 | 4.1% |
2022: 4.1%. Across these years the share ran from 3.9% to 5.7%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 8,341 tests reported to CDC for Essex County over 2022, 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: 2022. Measured data period: 2014 to 2022 (every CDC figure on file).
Essex County, Compared
Essex County radon figures, compared
Calculated by Radon411Only 339 of 8,341 radon tests reported for Essex County in 2022 reached 4 pCi/L (4.1%). The median result, 0.7 pCi/L, sits below 2, well under EPA's 4 pCi/L action level, and the top reported result was 29.7 pCi/L.
Across 21 New Jersey counties pooled together, 9.7% of tests reached that level, so Essex County runs 5.6 points below its state. Against the national pool of 23.9%, the gap is 19.8 points lower. Its place in the state: 17th of 21 New Jersey counties with 30 or more tests for the same period.
The reported tests do not follow EPA's Zone 2 label for Essex County (predicted average between 2 and 4 pCi/L): 4.1% of them reached 4 pCi/L, fewer than that label suggests. Of 5 neighbours with a figure, 4 reported a larger share at or above 4 pCi/L and 1 a smaller one; the spread is 3.4% (Hudson County) to 13.6% (Morris County).
Below the action level, 7,072 tests (84.8%) came in under 2 pCi/L, against 74.9% statewide, and 930 tests (11.1%) fell between 2 and 4, against 15.4% statewide. Over 9 years of annual figures the share held within 2 points, from 5.4% in 2014 to 4.1% in 2022; its peak was 5.7% in 2020. USGS geology rates 99% of the county's land low radon potential.
The busiest year on file was 2020, with 10,453 tests reported; the quietest, 2014, had 6,746.
Essex CountyNew Jersey, pooled
| Year | Tests | Essex County, at or above 4 pCi/L | New Jersey, pooled |
|---|---|---|---|
| 2014 | 6,746 | 5.4% | 12.8% |
| 2015 | 7,078 | 5.5% | 12.5% |
| 2016 | 7,437 | 4.8% | 12.5% |
| 2017 | 8,099 | 4.7% | 11.9% |
| 2018 | 8,736 | 3.9% | 11.0% |
| 2019 | 8,653 | 4.6% | 11.2% |
| 2020 | 10,453 | 5.7% | 11.7% |
| 2021 | 9,471 | 4.3% | 10.3% |
| 2022 | 8,341 | 4.1% | 9.7% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Essex County, Geology
The ground under Essex County
PredictedUSGS's geologic map puts all of Essex County's mapped land in one class: low radon potential. 99.4% of it lies in the area the map calls Northern Piedmont, 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 |
|---|---|---|---|---|
| Northern Piedmont | Sandstone, conglomerate, basalt, and shale. | Low | 8 | 99.4% |
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
Across New Jersey 29.8% of the land is rated high; none of Essex County's is. Of the 5 counties that border it, 4 have more high-potential ground, Morris County the most at 78.2%.
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 SectionRadon Section, run by New Jersey Department of Environmental Protection, licenses or certifies radon professionals, offers free or discounted test kits and states the rule for disclosing radon when a home is sold, and answers questions about testing and mitigation in New Jersey.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Check with your municipal or county health department for free radon test kits or purchase a test kit from a hardware store or a NJ certified radon business.
- Compare kits
- Professionals in New Jersey15 professionals are listed in New Jersey.
What New Jersey's program says
- Phone
- 800-648-0394
- Licensing of radon professionals
By law, all businesses and professionals conducting radon testing and mitigation in New Jersey must be certified by the DEP.
- Disclosure when a home is sold or rented
Under the law, the seller must provide the buyer, at the time the contract of sale is entered into, with a copy of the results of the radon test and evidence of any mitigation or treatment.
What it means
Essex County, Questions
Questions about radon in Essex County
Are radon levels high in Essex County?
In 2022, 4.1% of the radon tests reported to CDC for Essex County, New Jersey were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.7 pCi/L. Of 21 New Jersey counties with 30 or more tests for the same period, 16 reported a higher share; pooled, the state comes to 9.7%.
Which counties border Essex County?
Essex County borders 5 counties: Union County, Hudson County, Passaic County, Bergen County and Morris County.
Products
Essex County, Products
Testing a home in Essex County
In Essex County, 4.1% of 8,341 tests reported to CDC in 2022 reached 4 pCi/L, against 9.7% pooled across New Jersey. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Essex 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
lüft plug-in radon and indoor air quality monitor
- C-NRPP 2024/25: Approved
- Plug-in
- Wi-Fi, Bluetooth
- App only
First reading: Within 90 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Essex County, Bordering counties
Counties bordering Essex County
Calculated by Radon411- Radon levels in Morris CountyEPA zone 1
13.6%at or above 4 pCi/L
Median 1.1 pCi/L · 10,939 tests · 9.5 points above Essex County
- Radon levels in Passaic CountyEPA zone 2
7.5%at or above 4 pCi/L
Median 0.8 pCi/L · 4,825 tests · 3.4 points above Essex County
- Radon levels in Bergen CountyEPA zone 2
6.1%at or above 4 pCi/L
Median 1.0 pCi/L · 11,440 tests · 2.0 points above Essex County
- Radon levels in Union CountyEPA zone 2
5.1%at or above 4 pCi/L
Median 0.9 pCi/L · 6,111 tests · 1.0 points above Essex County
- Radon levels in Hudson CountyEPA zone 2
3.4%at or above 4 pCi/L
Median 0.5 pCi/L · 2,655 tests · 0.7 points below Essex County
Essex County, Cities and towns
Cities and towns in Essex County
The Census Bureau estimates 896,379 residents in Essex County for July 1, 2025, 36,445 more than in 2020 (+4.2%). Packed into its land, that is 7,109 people per square mile. Its largest town, Newark, has 323,808 residents, 36.1% of the total. Together its 7 incorporated places hold 47.9% of those residents; the other 52.1% live outside any of them. CDC's 8,341 reported tests for 2022 work out to 9.3 per 1,000 residents (2025 estimate), close to New Jersey's 11.4.
From Newark to Essex Fells, CDC publishes no figure by town: each reads Essex County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Newark | 323,808 | +4.3% | 36.1% |
| East Orange | 72,159 | +3.9% | 8.1% |
| Caldwell | 9,375 | +4.6% | 1.0% |
| Glen Ridge | 8,259 | +6.6% | 0.9% |
| North Caldwell | 6,815 | +2.5% | 0.8% |
| Roseland | 6,417 | +2.4% | 0.7% |
| Essex Fells | 2,235 | +0.7% | 0.2% |
7 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
Essex County has 335,550 homes, and many share a building: 31% are in buildings of five or more, 33% are detached houses, against 53% across New Jersey. The homes are older than New Jersey's as a whole: half were built before 1958 (1969 for New Jersey), and 53% date from before 1960. Most occupied homes here are rented: owners live in 45% (New Jersey: 64%). A tenant can run a test; a fix is the landlord's to make.
| Homes | Essex County | New Jersey |
|---|---|---|
| Housing units | 335,550 | 3,775,842 |
| Detached houses | 33% | 53% |
| In buildings of 5 or more | 31% | 22% |
| Mobile homes | under 1% | 1% |
| Built before 1960 | 53% | 38% |
| Built since 2000 | 13% | 15% |
| Middle year built | 1958 | 1969 |
| Owner-occupied | 45% | 64% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.