Massachusetts (MA) - Radon Levels & Risk Assessment
Massachusetts is classified as EPA Zone 2 (Moderate Potential) for radon potential, with an average indoor radon level of 3.4 pCi/L. While below the EPA action level of 4.0 pCi/L, many individual homes test above the threshold and the EPA recommends considering mitigation even at these levels. Approximately 22% of homes in Massachusetts have radon levels above 4.0 pCi/L.
Radon Data for Massachusetts
| EPA Zone | Zone 2 (Moderate Potential) |
| Average Indoor Level | 3.4 pCi/L |
| Homes Above 4.0 pCi/L | 22% |
| Risk Level | Moderate |
| Testing Requirement | Recommended but not required |
| Average Mitigation Cost | $1,500 |
Radon Risk in Massachusetts
As an EPA Zone 2 (Moderate Potential) state, Massachusetts has moderate radon potential. While not in the highest-risk category, many homes in the state test above the EPA action level, especially those with basements or those built on certain geological formations. The average indoor radon level of 3.4 pCi/L is below the EPA action level but above the level where the EPA suggests considering mitigation.
Testing and Mitigation in Massachusetts
While Massachusetts does not mandate radon testing, it is strongly recommended by both the EPA and state health agencies. Many home buyers include radon testing as part of their home inspection. The average cost of radon mitigation in Massachusetts is $1,500, which is above the national average. Professional radon testers and mitigators in Massachusetts can be found through the NRPP (National Radon Proficiency Program) or the NRSB (National Radon Safety Board) directories.
Protecting Your Home in Massachusetts
The EPA recommends that all homes in Massachusetts be tested for radon, regardless of the state's overall zone classification. If your home tests at 4.0 pCi/L or above, install a mitigation system. If your home tests between 2.0 and 4.0 pCi/L, the EPA suggests considering mitigation. New construction in Massachusetts may benefit from radon-resistant building techniques (RRNC), which are inexpensive to include during construction and can be easily activated later if radon levels are found to be elevated.
Use our radon risk assessment tool for a personalized estimate based on your home's characteristics, or browse all states to compare radon data across the country.