72%tests ≥ 4 pCi/L
3,730tests on record
6.4median pCi/L
Zone 1EPA zone (1993 prediction)

Test results in Delaware County

ResultShareEPA guidance
Below 2 pCi/L11%Below EPA's levels
2 to 4 pCi/L17%Consider fixing
4 pCi/L or more72%EPA recommends fixing

What the data shows

Where Delaware County sits among Ohio's 88 counties with dataEach dot is a county's share of tests at or above 4 pCi/L · Radon test results from laboratories, 2008–2017
0%20%40%60%80%

How Delaware County compares

Delaware 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
Delaware County72%Knox County72%Franklin County72%Licking County71%Marion County65%Morrow County65%Union County60%Ohio 52%
Data table
AreaTests ≥ 4 pCi/LTests
Delaware County72%3,730
Knox County72%1,530
Franklin County72%16,142
Licking County71%4,694
Marion County65%265
Morrow County65%177
Union County60%1,285
Ohio (88 counties)52%98,840

Same source as Delaware County.

What it means for your home

More than half of all results in Delaware 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: 3,730. 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