19%tests ≥ 4 pCi/L
7,706tests on record
1.4median pCi/L
Zone 1EPA zone (1993 prediction)

Test results in Baltimore County

ResultShareEPA guidance
Below 2 pCi/L61%Below EPA's levels
2 to 4 pCi/L19%Consider fixing
4 pCi/L or more19%EPA recommends fixing

What the data shows

Where Baltimore County sits among Maryland's 24 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%

How Baltimore County compares

Baltimore County ranks 5 of 7 among its neighboursShare of tests at or above 4 pCi/L · Radon test results from laboratories, 2008–2017 · whisker: 95% range
Kent County53%Carroll County42%Howard County31%Harford County23%Baltimore County19%Anne Arundel County17%Baltimore city8%Maryland 24%
Data table
AreaTests ≥ 4 pCi/LTests
Kent County53%57
Carroll County42%3,334
Howard County31%4,549
Harford County23%5,283
Baltimore County19%7,706
Anne Arundel County17%4,088
Baltimore city8%1,148
Maryland (24 counties)24%47,941

Same source as Baltimore County. Other bordering counties: York County, Pennsylvania.

What it means for your home

About 1 in 5 results in Baltimore 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: 7,706. 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