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Cambridge, MA Radon Levels

Check local Cambridge radon levels and find certified testing and mitigation professionals to keep your home safe


Cambridge, MA Radon Facts

EPA Radon Zone Zone 1 — High Risk > 4.0 pCi/L (Zone 1)
County Middlesex County, MA
Zip Code 02138

Historic Cambridge in Middlesex County within the Boston Metro shows an average radon level of 5.0 pCi/L, which exceeds the EPA action threshold of 4.0 pCi/L. Home to prestigious universities and densely built neighborhoods, the city's housing includes everything from 19th-century brownstones to modern high-rises, with many older buildings featuring basement levels. The 02138 area's glacial geology and urban density create unique radon accumulation patterns that warrant professional testing and potential mitigation.

7.28
pCi/L area average
Above EPA Action Level

Middlesex County average: 7.28 pCi/L, based on 90 user-submitted tests across 46 cities in the county. No homeowner readings have been submitted for Cambridge itself yet, so this county figure is the closest available benchmark. The EPA recommends taking action at or above 4.0 pCi/L.

0
4.0 EPA
10+

Cambridge, MA Radon Mitigation

Professional radon mitigation is the most effective way to permanently lower radon levels and protect your household.

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Cambridge, MA Radon Levels

User-submitted radon test readings from homes in the Cambridge area.

Radon LevelCityHome AgeFoundation
5 pCi/L Cambridge, MA 100+ Years Full Basement

Have a radon test result for Cambridge? Submit your reading to help other homeowners.

Radon Readings Near Cambridge, MA

Compare radon levels in Cambridge with the closest nearby cities that have user-submitted test data.

CityDistanceAvg User LevelReadings
Somerville 1.3 mi 4.50 pCi/L 4
Medford 3.1 mi 8.00 pCi/L 3
Everett 3.8 mi 4.50 pCi/L 2
Arlington 4.4 mi 4.00 pCi/L 2
Malden 4.5 mi 5.00 pCi/L 2
Newton Center 4.8 mi 4.50 pCi/L 2
Newtonville 5.4 mi 3.00 pCi/L 1
Winchester 5.9 mi 4.00 pCi/L 2

Middlesex County Radon Profile

The bedrock and soils beneath Middlesex County are classified by the EPA as Radon Zone 1, the highest-risk tier, with predicted average indoor screening levels above 4 pCi/L. Homeowner-submitted tests from 46 cities in Middlesex County average 7.28 pCi/L across 90 tests — above the EPA's 4 pCi/L action level, reinforcing the need for testing across the county. Radon is the second leading cause of lung cancer in the United States, and a short-term test is the only way to confirm a specific home's level in Middlesex County.

Radon FAQ for Cambridge, MA

What EPA Radon Zone is Cambridge in?
Cambridge and the 02138 zip code are in Middlesex County, which has an EPA assigned Radon Zone of 1. A zone of 1 predicts an average indoor radon screening level greater than 4 pCi/L.
Why are radon readings shown from areas near Cambridge?
No homeowner radon tests have been submitted for Cambridge yet. Because radon is driven by regional soil and bedrock geology, readings from the closest cities—and the Middlesex County average—are the best available indicator of local conditions until Cambridge homeowners submit their own results. The EPA still recommends testing every individual home, since levels can vary significantly from house to house.
How much does radon mitigation cost in Cambridge?
Radon mitigation in Cambridge typically costs between $800 and $2,000. Most homes with standard basements can be mitigated with a sub-slab depressurization system in the $1,000–$1,500 range. Factors that can increase cost include complex foundations, crawl spaces, or very high radon levels.
Should I test for radon if I'm buying a home in Cambridge?
Yes. Radon testing should be part of every home purchase. A short-term radon test is typically included as part of the home inspection process and costs $150–$250. If elevated levels are found, you can negotiate mitigation as part of the sale.