Short-term kit
Air Chek Short-Term radon test kit you hang, lab fee included
- Lab fee included
In home: 72 to 168 hours
Locations and reports
Radon Levels in Salem County, New Jersey
EPA puts Salem County in Zone 2, its middle radon zone, and most reported tests there come back low, though 10.8% of 454 (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
10.8%
1.1 pts above NJ
- Salem
- 10.8%
- New Jersey
- 9.7%
454 tests, 2022
Median result
1.1pCi/L
Below action level
- Salem
- 1.1 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2022
Tests reported
454
20th of 21 by tests
- Salem
- 454
- 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
7 of 21
Middle half
- Salem
- 10.8%
- Warren
- 24.6%
By share, of 21 with 30+ tests
Read a result for Salem County
Starts at Salem County's median, 1.1 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 1.1 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. Salem County's median reported result, 2022.
The data
Salem County, At a glance
Salem County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Salem County is a
USGS geologic potential: Low across 79% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Salem County, 2022
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 12.2% |
| 2015 | 4.8% |
| 2016 | 12.6% |
| 2017 | 12.3% |
| 2018 | 9.5% |
| 2019 | 10.3% |
| 2020 | 12.6% |
| 2021 | 10.3% |
| 2022 | 10.8% |
2022: 10.8%. Across these years the share ran from 4.8% to 12.6%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 454 tests reported to CDC for Salem 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).
Salem County, Compared
Salem County radon figures, compared
Calculated by Radon41110.8% of its 454 tests in 2022 were at or above 4 pCi/L. That is 1.1 points above the 9.7% pooled from 21 New Jersey counties.
Ordered from highest share down, it comes 7th of 21 New Jersey counties with 30 or more tests for the same period. Nationally, every county with a figure for the same period pools to 23.9%; Salem County sits 13.1 points below it.
Next door, the shares run from 8.6% in Cumberland County to 12.2% in Gloucester County, with Cumberland County below Salem County. Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 10.8% share point the same way here.
Half the tests came in under 1.1 pCi/L and half over it; the single highest reached 19.3 pCi/L. The rest split 69.4% under 2 pCi/L and 19.8% from 2 to 4 (New Jersey: 74.9% and 15.4%). Year by year, 2014 opened at 12.2% and 2022 closed at 10.8% (about level), with 2016 the high at 12.6%.
The busiest year on file was 2021, with 552 tests reported; the quietest, 2015, had 186.
Salem CountyNew Jersey, pooled
| Year | Tests | Salem County, at or above 4 pCi/L | New Jersey, pooled |
|---|---|---|---|
| 2014 | 197 | 12.2% | 12.8% |
| 2015 | 186 | 4.8% | 12.5% |
| 2016 | 294 | 12.6% | 12.5% |
| 2017 | 326 | 12.3% | 11.9% |
| 2018 | 347 | 9.5% | 11.0% |
| 2019 | 464 | 10.3% | 11.2% |
| 2020 | 531 | 12.6% | 11.7% |
| 2021 | 552 | 10.3% | 10.3% |
| 2022 | 454 | 10.8% | 9.7% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Salem County, Geology
The ground under Salem County
PredictedMost of the ground under Salem County is one class on USGS's geologic map: 78.8% of its land is low radon potential, with 21.0% moderate. The map puts 78.8% of Salem County in the area it calls Outer Coastal Plain and 21.0% in Inner Coastal Plain. USGS gives the first a radon index of 8, in the low band (5 to 8), and the second 10, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Outer Coastal Plain | Upper Tertiary-Quaternary gravel, sand, silt, clay. | Low | 8 | 78.8% |
| Inner Coastal Plain | Cretaceous-Lower Tertiary gravel, sand, silt, clay. | Moderate | 10 | 21.0% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Salem County beside the ground around it
Across New Jersey 29.8% of the land is rated high; none of Salem County's is. Of the 3 counties that border it, 2 have more moderate-potential ground, New Castle County, DE the most at 63.8%.
The map rates the ground, not the air in any home.
Local help
Salem County, Local resources
Radon testing and mitigation in Salem 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
Salem County, Questions
Questions about radon in Salem County
Are radon levels high in Salem County?
In 2022, 10.8% of the radon tests reported to CDC for Salem County, New Jersey were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.1 pCi/L. Of 21 New Jersey counties with 30 or more tests for the same period, 6 reported a higher share; pooled, the state comes to 9.7%.
Which counties border Salem County?
Salem County borders 3 counties: Gloucester County, NJ, Cumberland County, NJ and New Castle County, DE.
Products
Salem County, Products
Testing a home in Salem County
In Salem County, 10.8% of 454 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 Salem 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
RM-63Pro rechargeable radon monitor with a touchscreen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Salem County, Bordering counties
Counties bordering Salem County
Calculated by Radon411- Radon levels in Gloucester County, NJEPA zone 2
12.2%at or above 4 pCi/L
Median 1.1 pCi/L · 3,333 tests · 1.4 points above Salem County
- Radon levels in Cumberland County, NJEPA zone 2
8.6%at or above 4 pCi/L
Median 0.9 pCi/L · 752 tests · 2.2 points below Salem County
- Radon levels in New Castle County, DEEPA zone 2
No CDC figure for 2022; its page reads it against its own neighbours.
Salem County, Cities and towns
Cities and towns in Salem County
The Census Bureau estimates 66,280 residents in Salem County for July 1, 2025, 1,499 more than in 2020 (+2.3%). That works out to 200 people per square mile of land. No town dominates: Salem, the largest, has 5,389 residents, 8.1% of the total. Together its 4 incorporated places hold 23.4% of those residents; the other 76.6% live outside any of them. Reported testing is thin here: 454 tests over 2022, or 6.8 for every 1,000 residents (2025 estimate), where New Jersey as a whole comes to 11.4.
From Salem to Elmer, CDC publishes no figure by town: each reads Salem County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Salem | 5,389 | +1.9% | 8.1% |
| Penns Grove | 4,934 | +2.0% | 7.4% |
| Woodstown | 3,784 | +2.7% | 5.7% |
| Elmer | 1,376 | +3.1% | 2.1% |
4 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).
Salem County, Homes
Homes in Salem County
Of Salem County's 27,740 homes, 74% are detached houses, against 53% across New Jersey; 10% are in buildings of five or more homes. Half of its homes were built before 1963, close to New Jersey's 1969: 46% date from before 1960 and 9% from 2000 or later. 71% of occupied homes are lived in by their owner (New Jersey: 64%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Salem County | New Jersey |
|---|---|---|
| Housing units | 27,740 | 3,775,842 |
| Detached houses | 74% | 53% |
| In buildings of 5 or more | 10% | 22% |
| Mobile homes | 4% | 1% |
| Built before 1960 | 46% | 38% |
| Built since 2000 | 9% | 15% |
| Middle year built | 1963 | 1969 |
| Owner-occupied | 71% | 64% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.