Radon levels in Worcester County, Massachusetts

ModerateEPA Zone 1

Predicted long-term basement average of 2.5 pCi/L (model estimate) across 78 ZIP codes - about 1.4× the US average of 1.8, about 1.4× the Massachusetts average of 1.8. Ranked #1 of 14 Massachusetts counties.

Test Worcester County, MA - the EPA says "consider fixing" in this range

The predicted basement average here is 2.5 pCi/L, in the 2-4 pCi/L band where the EPA recommends considering mitigation. Plenty of individual homes in a moderate area test above 4. Start with a short-term test; if it comes back at 2 or higher, follow up with a long-term test or a continuous monitor.

Already tested at 4 pCi/L or higher? Find a certified mitigation professional (EPA). A mitigation system typically runs $800-$2,500 installed.

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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.

2.5 ± 0.07

pCi/L predicted basement mean (model SD)

1.4 ± 0.07

pCi/L predicted upstairs (above-ground) mean

1.5-4.4

range of ZIP-level basement predictions in the county

What this means for Worcester

The typical Worcester County home is predicted in the 2-4 pCi/L band. The EPA's guidance for this range is to consider fixing, because there is no known safe level and roughly one home in several in a moderate area will test above 4.

Note that the EPA classifies Worcester County as Zone 1 while the newer model predicts 2.5 pCi/L. The zone map predates two decades of test data; where they disagree, we grade on the model but show both. County figures weight each ZIP by its 2010 Census population, so they describe where people live rather than empty land.

Comparable Massachusetts counties: Essex County (2.0), Barnstable County (2.0), Dukes County (1.9), Middlesex County (1.8).

ZIP codes in Worcester County

Predicted basement and upstairs means by ZIP (model estimate). ZIPs whose land is mostly in this county.

ZIPBasementUpstairsGrade
014532.1 ± 0.061.2Moderate
014202.6 ± 0.071.3Moderate
015452.8 ± 0.051.9Moderate
016042.5 ± 0.061.1Moderate
017571.5 ± 0.051.2Low
016052.5 ± 0.070.6Moderate
016101.8 ± 0.060.8Low
016022.9 ± 0.061.5Moderate
016092.6 ± 0.071.3Moderate
014402.3 ± 0.081.3Moderate
016032.8 ± 0.081.1Moderate
016062.6 ± 0.071.3Moderate
015812.1 ± 0.051.4Moderate
015703.3 ± 0.071.5Moderate
015502.0 ± 0.061.0Moderate
015013.5 ± 0.071.8Moderate
015322.3 ± 0.051.7Moderate
015203.3 ± 0.061.9Moderate
015102.3 ± 0.061.4Moderate
015692.6 ± 0.061.7Moderate
013311.8 ± 0.060.9Low
015272.6 ± 0.061.6Moderate
015073.0 ± 0.081.7Moderate
015622.7 ± 0.081.6Moderate
015714.1 ± 0.072.1High
015403.1 ± 0.061.7Moderate
014752.0 ± 0.121.6Moderate
014622.9 ± 0.061.7Moderate
015882.4 ± 0.071.4Moderate
017722.1 ± 0.061.5Moderate
015041.9 ± 0.071.4Low
015902.6 ± 0.061.7Moderate
015162.5 ± 0.071.7Moderate
016072.3 ± 0.071.1Moderate
015433.0 ± 0.091.9Moderate
015642.8 ± 0.081.6Moderate
015833.1 ± 0.081.8Moderate
015232.6 ± 0.071.6Moderate
015682.2 ± 0.071.4Moderate
014732.9 ± 0.101.8Moderate
015362.4 ± 0.061.6Moderate
015243.2 ± 0.071.9Moderate
015192.3 ± 0.061.6Moderate
015662.0 ± 0.071.6Low
014303.1 ± 0.081.8Moderate
017471.6 ± 0.061.3Low
017562.0 ± 0.061.4Low
015342.6 ± 0.071.5Moderate
010052.3 ± 0.071.5Moderate
017402.8 ± 0.062.0Moderate
016122.7 ± 0.071.8Moderate
014512.7 ± 0.061.9Moderate
015352.4 ± 0.071.7Moderate
015852.3 ± 0.071.6Moderate
015603.1 ± 0.121.7Moderate
014522.6 ± 0.061.8Moderate
015054.4 ± 0.112.2High
014682.5 ± 0.071.6Moderate
016082.0 ± 0.070.9Moderate
015412.7 ± 0.071.8Moderate
015062.3 ± 0.071.7Moderate
014362.3 ± 0.061.4Moderate
015222.9 ± 0.061.8Moderate
015292.1 ± 0.051.5Moderate
015182.3 ± 0.071.6Moderate
015032.6 ± 0.061.8Moderate
015372.5 ± 0.051.5Moderate
016112.6 ± 0.051.7Moderate
015422.9 ± 0.061.7Moderate
015152.4 ± 0.061.7Moderate
010682.5 ± 0.061.8Moderate
014341.9 ± 0.081.2Low
010922.0 ± 0.061.3Moderate
010311.8 ± 0.051.1Low
013661.7 ± 0.061.0Low
013681.9 ± 0.061.1Low
015312.4 ± 0.051.6Moderate
017451.9 ± 0.051.4Low

If your test comes back at 4 pCi/L or higher

Mitigation is a routine job: a fan-driven pipe that vents soil gas from under the slab to above the roofline, typically $800-$2,500 installed (typical range; local quotes vary). Use certified professionals: EPA find-a-professional. Read the full mitigation guide.

Worcester County radon questions

Is radon high in Worcester County, Massachusetts?
Moderate. The model predicts a long-term basement average of 2.5 pCi/L in Worcester County (about 1.4× the US average of 1.8 and about 1.4× the Massachusetts average of 1.8). That is in the 2-4 pCi/L range where the EPA recommends considering mitigation. Ranked 1 of 14 Massachusetts counties.
Should I test for radon in Worcester County?
Yes, soon. With a predicted average of 2.5 pCi/L and at least one ZIP predicted at 4.4, many homes in Worcester County will test above the 4 pCi/L action level. Use a short-term kit first; if it reads 2 or higher, confirm with a long-term test or continuous monitor before deciding on mitigation.
What does EPA Radon Zone 1 mean for Worcester County?
Zone 1 - highest potential (predicted average > 4 pCi/L). The zone map dates from 1993 and classifies whole counties. The newer model's predicted average of 2.5 pCi/L does not line up with Zone 1, which is common - the EPA itself says high-radon homes exist in every zone. Neither replaces a test of your own home.
How much does radon mitigation cost in Worcester County?
A standard active sub-slab depressurization system typically runs $800-$2,500 installed nationally; Massachusetts quotes vary with foundation type (slab, crawlspace, basement), home size and local labor. Get two or three bids from certified mitigators listed by your state radon program or the EPA's find-a-professional page.

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