Home › Massachusetts
State overview
Radon in Massachusetts
Of Massachusetts's 14 counties and county equivalents, EPA places 3 in Zone 1, 10 in Zone 2, 1 in Zone 3. Zones are county-wide predictions; testing is the only way to know your home's level.
Radon in the news
Massachusetts stories
- Report: High levels of cancer-causing radon gas detected in one-fifth of Massachusetts homesBoston 25 News · 2024-01-08
Headlines link to the original publishers via Google News. Updated 2026-10-27.
All 14 counties
| County | EPA zone |
|---|---|
| Barnstable County | Zone 2 |
| Berkshire County | Zone 2 |
| Bristol County | Zone 2 |
| Dukes County | Zone 2 |
| Essex County | Zone 1 |
| Franklin County | Zone 2 |
| Hampden County | Zone 2 |
| Hampshire County | Zone 2 |
| Middlesex County | Zone 1 |
| Nantucket County | Zone 2 |
| Norfolk County | Zone 2 |
| Plymouth County | Zone 2 |
| Suffolk County | Zone 3 |
| Worcester County | Zone 1 |
Source: EPA radon zones spreadsheet (EPA 402/A-16/001).