39%tests ≥ 4 pCi/L
7,903tests on record
3.0median pCi/L
Zone 1EPA zone (1993 prediction)

Test results in Washington County

ResultShareEPA guidance
Below 2 pCi/L34%Below EPA's levels
2 to 4 pCi/L27%Consider fixing
4 pCi/L or more39%EPA recommends fixing

What the data shows

How Washington County compares

Washington County has the highest share of high results among its neighboursShare of tests at or above 4 pCi/L · Radon test results from laboratories, 2008–2017 · whisker: 95% range
Washington County39%New London County, Connec…28%Kent County26%Newport County24%Suffolk County, New York8%Rhode Island 24%
Data table
AreaTests ≥ 4 pCi/LTests
Washington County39%7,903
New London County, Connecticut28%2,081
Kent County26%7,657
Newport County24%2,792
Suffolk County, New York8%551
Rhode Island (5 counties)24%37,874

Same source as Washington County.

What it means for your home

About 1 in 3 results in Washington County were at or above 4 pCi/L, where the EPA recommends a fix. Only a test shows your own home's level.

Levels in pCi/L from the EPA. The WHO reference level is 100 Bq/m³, about 2.7 pCi/L.

Test your home

Start with a short-term test (2–90 days) and confirm a result of 4 pCi/L or more with a second test. EPA guide

Sponsored: we earn a commission on purchases through these links. We haven't tested Airthings monitors yet.

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Fixing high radon

No local job records yet. National range: $800–$2,500, average $1,200 (EPA, 2003). Cost guide →

About this data

Source: Radon test results from laboratories (CDC Environmental Public Health Tracking Network). Period: 2008–2017. Tests: 7,903. Read the methodology →

These are voluntary and real-estate tests, not a random sample of homes, so they describe tested homes rather than every home.

About this page

Published by Ray Roman, editor of Radon by County. Figures are loaded from the cited source and spot-checked against it. Editorial policy · About us