Radon levels in Boston, Massachusetts
LowEPA Zone 3Predicted long-term basement average of 1.3 pCi/L (model estimate) across the 25 modeled ZIP codes in Boston - about 30% below the US average of 1.8, about 30% below the Massachusetts average of 1.8. Ranked #24 of 29 Massachusetts cities on this site. Most of the city lies in Suffolk County (its ZIPs also reach into 1 other county).
Test Boston, MA once anyway - radon varies house to house
The predicted basement average here is 1.3 pCi/L, below the EPA's 2 pCi/L "consider fixing" threshold. That's good news for the area - but the EPA still recommends every home be tested, because foundation cracks, soil pockets and ventilation make one house very different from its neighbor. One inexpensive kit settles it.
We may earn a commission from Amazon at no extra cost to you.
Predicted (model estimate). The pCi/L figures on this page are long-term area averages from a peer-reviewed national model built on millions of real radon tests (2001-2021). They describe the typical home in this area - not your home, which can be several times higher or lower. The EPA radon zone is a separate, 1993 county-level classification. How the numbers work.
1.3 ± 0.06
pCi/L predicted basement mean (model SD)
0.6 ± 0.08
pCi/L predicted upstairs (above-ground) mean
0.8-1.6
range of ZIP-level basement predictions in the city
0%
of Boston ZIPs predicted ≥ 4 pCi/L (0% ≥ 2)
What this means for Boston
The typical Boston home is predicted below 2 pCi/L, the lowest band. That describes the average house; the ZIP-level predictions inside the city still span 0.8 to 1.6 pCi/L.
The city figure is not a separate estimate: it is the mean of the model's ZIP-code predictions, weighted by the share of the city's land in each ZIP (Census 2020 ZCTA-to-place relationship file). The 1993 EPA zone (3) for Suffolk and the 2001-2021 model agree here.
Comparable Massachusetts cities: Somerville (1.2), Cambridge (1.3), Springfield (1.2), Revere (1.2).
ZIP codes in Boston
ZIPs that overlap the city, largest share of its land first. Predicted basement and upstairs means are model estimates; ZIPs the model does not cover show a dash.
| ZIP | Share of city | Basement | Upstairs | Grade |
|---|---|---|---|---|
| 02132 | 10% | 1.5 ± 0.06 | 0.8 | Low |
| 02128 | 10% | 0.8 ± 0.09 | 0.5 | Low |
| 02136 | 10% | 1.6 ± 0.06 | 0.7 | Low |
| 02130 | 8% | 1.6 ± 0.06 | 0.6 | Low |
| 02124 | 6% | 1.3 ± 0.06 | 0.5 | Low |
| 02131 | 6% | 1.5 ± 0.05 | 0.7 | Low |
| 02135 | 6% | 1.3 ± 0.07 | 0.6 | Low |
| 02125 | 5% | 1.2 ± 0.06 | 0.5 | Low |
| 02127 | 4% | 1.0 ± 0.07 | 0.5 | Low |
| 02121 | 4% | 1.1 ± 0.07 | 0.4 | Low |
| 02126 | 4% | 1.4 ± 0.05 | 0.6 | Low |
| 02122 | 4% | 1.2 ± 0.05 | 0.5 | Low |
| 02119 | 3% | 1.1 ± 0.06 | 0.5 | Low |
| 02129 | 3% | 1.0 ± 0.08 | 0.6 | Low |
| 02134 | 3% | 1.2 ± 0.05 | 0.7 | Low |
| 02118 | 2% | 0.9 ± 0.09 | 0.5 | Low |
| 02210 | 2% | 1.1 ± 0.05 | 0.6 | Low |
| 02215 | 2% | 1.1 ± 0.06 | 0.7 | Low |
| 02115 | 2% | 1.1 ± 0.06 | 0.6 | Low |
| 02116 | 1% | 1.0 ± 0.08 | 0.6 | Low |
| 02120 | 1% | 1.2 ± 0.06 | 0.6 | Low |
| 02467 | 1% | 1.6 ± 0.06 | 0.8 | Low |
| 02114 | 1% | 1.0 ± 0.06 | 0.6 | Low |
| 02108 | 1% | — | — | no model |
| 02109 | <1% | 1.0 ± 0.06 | 0.6 | Low |
| 02110 | <1% | 1.1 ± 0.06 | 0.6 | Low |
| 02111 | <1% | — | — | no model |
| 02163 | <1% | — | — | no model |
| 02113 | <1% | — | — | no model |
| 02199 | <1% | — | — | no model |
| 02205 | <1% | — | — | no model |
| 02133 | <1% | — | — | no model |
| 02203 | <1% | — | — | no model |
Testing help in Massachusetts
We link only state program pages we could verify, and Massachusetts's did not respond when we checked, so start from the EPA state radon contacts page. If a test comes back at 4 pCi/L or higher, mitigation typically costs $800-$2,500 installed; use EPA find-a-professional and read the mitigation guide.
Boston radon questions
- Is radon high in Boston, Massachusetts?
- Low. Averaging the model's ZIP-code predictions across Boston (weighted by how much of the city each ZIP covers) gives a long-term basement mean of 1.3 pCi/L - about 30% below the US average of 1.8 and about 30% below the Massachusetts average of 1.8. That is below the EPA's 2 pCi/L "consider fixing" threshold, though individual homes still vary. Boston ranks 24 of 29 Massachusetts cities on this site.
- Which Boston ZIP codes have the highest radon?
- Predictions for the 25 modeled ZIP codes in Boston range from 0.8 to 1.6 pCi/L in the basement. 0% of them are predicted at or above 4 pCi/L and 0% at or above 2. The city is fairly uniform, so the city-wide number is a reasonable guide for any neighborhood.
- Should I test for radon in Boston?
- Yes, once. The EPA recommends testing every home regardless of area. A short-term kit costs little and settles the question for your house; Boston's low predicted average describes the typical home, not yours.
- What does EPA Radon Zone 3 mean for Boston?
- Boston sits mainly in Suffolk County, which the EPA classifies as Zone 3 - low potential (< 2 pCi/L). The zone map dates from 1993 and covers whole counties. The 2001-2021 model agrees with the zone for the city. Neither replaces a test of your own home.
← All Massachusetts counties and cities · Suffolk County · How to test · Methodology