49%tests ≥ 4 pCi/L
341tests on record
—median pCi/L
Zone 1EPA zone (1993 prediction)

Test results in Branch County

ResultShareEPA guidance
Below 2 pCi/L26%Below EPA's levels
2 to 4 pCi/L25%Consider fixing
4 pCi/L or more49%EPA recommends fixing

What the data shows

Where Branch County sits among Michigan's 83 counties with dataEach dot is a county's share of tests at or above 4 pCi/L · Michigan indoor radon test results, 2016–2026
0%20%40%60%

How Branch County compares

Branch County has the highest share of high results among its neighboursShare of tests at or above 4 pCi/L · Michigan indoor radon test results, 2016–2026 · whisker: 95% range
Branch County49%Hillsdale County46%St. Joseph County36%Kalamazoo County27%Calhoun County25%Michigan 23%
Data table
AreaTests ≥ 4 pCi/LTests
Branch County49%341
Hillsdale County46%566
St. Joseph County36%263
Kalamazoo County27%1,413
Calhoun County25%875
Michigan (83 counties)23%56,518

Same source as Branch County. Other bordering counties: LaGrange County, Indiana, Steuben County, Indiana.

What it means for your home

About 1 in 2 results in Branch 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 →

Michigan doesn't license radon mitigators; look for NRPP or NRSB certification. Source

Buying or selling here

Michigan's Seller's Disclosure Statement asks whether the seller knows of environmental hazards on the property, including radon gas (MCL 565.957). Source

Checked against the official text on 2026-11-03. Not legal advice.

About this data

Source: Michigan indoor radon test results (Michigan Department of Environment, Great Lakes, and Energy). Period: 2016–2026. Tests: 341. 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