Massachusetts — 4.8M metro

Radon in Boston,
MA

Massachusetts sits in EPA Zone 2, with the Department of Public Health reporting 15–20% of tested homes exceeding the action level. Communities in MetroWest and western suburbs show higher rates than coastal Boston due to granite-underlying geology.

Risk Level

Moderate Risk

1–5 pCi/L

Typical range (area avg.)

EPA action level: 4 pCi/L

Why Boston Has Moderate Risk Radon

Massachusetts bedrock is largely granite and metamorphic rock from the Avalon Terrane — a uranium-bearing geological province. The New England Upland, which includes many Boston suburbs, sits directly on this radon-generating bedrock.

Local Housing and Radon Risk

Greater Boston has extensive older housing stock — New England's iconic Cape Cods, Colonials, and Triple Deckers. While triple-deckers (no private basement) have lower risk, single-family Colonial homes with full basements throughout suburbs like Newton, Needham, and Framingham should be tested.

Testing Advice for Boston Residents

Massachusetts DEP maintains a certified contractor database. The state requires radon testing disclosure in real estate transactions. MetroWest communities (Framingham, Natick, Sudbury) have elevated municipal radon awareness programs.

How to Test Your Boston Home

Step 1: Choose Your Test Type

For initial screening, a charcoal short-term test kit ($12–$25) placed for 48–96 hours provides a quick result. For the most accurate reading, a long-term alpha-track test ($20–$35) left in place for 90+ days accounts for seasonal variation — especially important in Boston's climate.

Step 2: Place the Test Correctly

Test in your lowest livable level — basement if you have one, otherwise the first floor. Keep the test 20 inches from the floor, away from windows and exterior walls. Close windows and doors 12 hours before and during the test for accurate results.

Step 3: Interpret Your Results

Below 2 pCi/L: low concern, retest every 2 years. 2–4 pCi/L: consider mitigation, retest in 2 years. 4 pCi/L or higher: the EPA recommends mitigation. Above 8 pCi/L: prioritize mitigation promptly.

Step 4: Hire a Certified Mitigator if Needed

If your test result is at or above 4 pCi/L, hire a certified radon mitigator. In Massachusetts, always verify your contractor's state certification. Sub-slab depressurization — the most effective mitigation method — typically costs $900–$1,700 installed in the Boston area.

Frequently Asked Questions — Radon in Boston

Is radon a real problem in Boston?

Yes. Massachusetts sits in EPA Zone 2, with the Department of Public Health reporting 15–20% of tested homes exceeding the action level. Communities in MetroWest and western suburbs show higher rates than coastal Boston due to granite-underlying geology. The EPA recommends all homes be tested regardless of location — radon levels can vary significantly even between neighboring properties.

How much does radon mitigation cost in this area?

In the Boston area, professional radon mitigation (sub-slab depressurization) typically costs $900–$1,700 installed. This is a one-time cost that reduces radon by 50–99%. The system requires minimal maintenance and a mitigator can typically complete the work in 3–5 hours.

Should I test if I have a new home?

Absolutely. New homes built with radon-resistant features still show elevated levels in testing — construction conditions and local geology vary too much to assume any home is safe. Test within the first year of occupancy, especially if your home has a basement.

Can I test radon myself, or do I need a professional?

DIY testing is reliable and recommended as a first step. Short-term kits ($12–$25) and long-term kits ($20–$35) are accurate when placed and returned correctly. Professional testing is only required for real estate transactions in some states. If your DIY test shows elevated levels, use a certified professional for both confirmation testing and mitigation.