Michigan · county radon data
Radon in Kalamazoo County, Michigan
33.3% of the 3,261 home radon tests on record here reached the EPA action level — among the higher-testing counties in the state, ranked #17 of 83 tested Michigan counties.
What the numbers say
Kalamazoo County sits 16.7 points above the Michigan median (16.6% of tests over the limit across the state's counties). The median reading among its 3,261 reported tests was 2.8 pCi/L — and the single highest test on record reached 35.6 pCi/L. EPA maps place the county in Radon Zone 1 — its highest-potential category, where average indoor screening levels are predicted above 4 pCi/L.
Why: the ground under Kalamazoo County
Covered in thick glacial drift over the Michigan Basin's sedimentary rocks. Radon potential is moderate for most of the state, but tills incorporating shale or carbonate fragments can push individual homes well over the action level — testing is the only way to know. (Regional attribution here is well supported; unit-level detail is coarser — see methodology.)
Geology sources: USGS WRI 98-4169 · EPA MI zone documentation.
The housing stock factor
The median Kalamazoo County home dates to 1975 — decades before radon-resistant new construction entered building codes. With 262,375 residents largely housed in that older stock, testing is the only way any individual household knows where it stands.
ZIP codes in Kalamazoo County
Michigan doesn't publish ZIP-level test results, so these ZIPs share the county figures above — the roster is here so you can confirm your address is covered by this data.
| ZIP | Place |
|---|---|
| 49001 | Kalamazoo |
| 49002 | Portage |
| 49004 | Kalamazoo |
| 49006 | Kalamazoo |
| 49007 | Kalamazoo |
| 49008 | Kalamazoo |
| 49009 | Kalamazoo |
| 49012 | Augusta |
| 49024 | Portage |
| 49034 | Climax |
| 49048 | Kalamazoo |
| 49052 | Fulton |
| 49053 | Galesburg |
| 49074 | Nazareth |
| 49083 | Richland |
| 49087 | Schoolcraft |
| 49088 | Scotts |
| 49097 | Vicksburg |
Kalamazoo County in the Michigan picture
| Kalamazoo County | 33.3% over the limit | 3,261 tests |
| Michigan's highest: Lenawee County | 56.7% | 1,349 tests |
| Michigan county median | 16.6% | 83 counties ranked |
| Share of all Michigan tests from this county | 4.0% | |
Ranked nearby in Michigan
- Eaton County — #14, 34.4% of 2,180 tests over the limit
- St. Joseph County — #15, 34.1% of 652 tests over the limit
- Lapeer County — #16, 33.4% of 479 tests over the limit
- Shiawassee County — #18, 31.6% of 1,021 tests over the limit
- Barry County — #19, 30.7% of 1,078 tests over the limit
- Cass County — #20, 30.4% of 449 tests over the limit
(Ranking neighbors — counties adjacent in the Michigan test ranking, not necessarily on the map.)
High test? Fixes and real pricing: the Michigan mitigation cost guide. Every statistic here traces to the methodology (CDC EPHT (labs), 2008–2017; zones: EPA; year built & population: ACS 5-year).
Kalamazoo County radon FAQ
- Is radon high in Kalamazoo County?
- 33.3% of 3,261 home tests reported to the CDC came back at or above the EPA action level of 4 pCi/L — 16.7 points above the Michigan county median of 16.6%, ranking #17 of 83 tested counties. EPA classifies the county as Zone 1.
- Does an older home in Kalamazoo County mean more radon risk?
- The county's median home was built in 1975 — before radon-resistant construction practices entered building codes in the 1990s, so most of the housing stock has no built-in radon protection. Construction age changes the odds, not the answer: only a test tells you about your house.
- Where do these Kalamazoo County numbers come from?
- 3,261 aggregated home tests in the CDC's Environmental Public Health Tracking dataset (CDC EPHT 2008-2017). Median reading: 2.8 pCi/L; the highest recorded test hit 35.6 pCi/L. How we handle the data, including its limits, is documented on our methodology page.
- What's the highest radon reading recorded in Kalamazoo County?
- 35.6 pCi/L — 8× the EPA action level — against a county median of 2.8 pCi/L across 3,261 tests. That spread is the point: neighboring homes routinely test wildly differently.