Radon zones in Massachusetts
| Barnstable County | Massachusetts | 2 |
| Berkshire County | Massachusetts | 2 |
| Bristol County | Massachusetts | 2 |
| Essex County | Massachusetts | 1 |
| Franklin County | Massachusetts | 2 |
| Hampden County | Massachusetts | 2 |
| Hampshire County | Massachusetts | 2 |
| Middlesex County | Massachusetts | 1 |
| Norfolk County | Massachusetts | 2 |
| Plymouth County | Massachusetts | 2 |
| Worcester County | Massachusetts | 1 |
Sources
- Massachusetts: EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
- EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
- Massachusetts: EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
- EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
- Massachusetts: EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
- EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
- Massachusetts: EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
- EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
- Massachusetts: EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
- EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
- Massachusetts: EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
- EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
"Secondary" marks a source used only because the official page could not be read.