Michigan · county radon data
Radon in Macomb County, Michigan
13.4% of the 4,659 home radon tests on record here reached the EPA action level — mid-pack for the state, ranked #56 of 83 tested Michigan counties.
What the numbers say
Macomb County sits 3.2 points below the Michigan median (16.6% of tests over the limit across the state's counties). The median reading among its 4,659 reported tests was 1.6 pCi/L — and the single highest test on record reached 34.3 pCi/L. EPA maps place the county in Radon Zone 3 — lower predicted potential, though individual homes here still test high; zone maps predict averages, not addresses.
Why: the ground under Macomb 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 Macomb County home dates to 1975 — decades before radon-resistant new construction entered building codes. With 879,853 residents largely housed in that older stock, testing is the only way any individual household knows where it stands.
ZIP codes in Macomb 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 |
|---|---|
| 48005 | Armada |
| 48015 | Center Line |
| 48021 | Eastpointe |
| 48026 | Fraser |
| 48035 | Clinton Township |
| 48036 | Clinton Township |
| 48038 | Clinton Township |
| 48042 | Macomb |
| 48043 | Mount Clemens |
| 48044 | Macomb |
| 48045 | Harrison Township |
| 48047 | New Baltimore |
| 48048 | New Haven |
| 48050 | New Haven |
| 48051 | New Baltimore |
| 48062 | Richmond |
| 48065 | Romeo |
| 48066 | Roseville |
| 48080 | Saint Clair Shores |
| 48081 | Saint Clair Shores |
| 48082 | Saint Clair Shores |
| 48088 | Warren |
| 48089 | Warren |
| 48091 | Warren |
| 48092 | Warren |
| 48093 | Warren |
| 48094 | Washington |
| 48095 | Washington |
| 48096 | Ray |
| 48310 | Sterling Heights |
| 48312 | Sterling Heights |
| 48313 | Sterling Heights |
| 48314 | Sterling Heights |
| 48315 | Utica |
| 48316 | Utica |
| 48317 | Utica |
Macomb County in the Michigan picture
| Macomb County | 13.4% over the limit | 4,659 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 | 5.7% | |
Ranked nearby in Michigan
- Montmorency County — #53, 14.7% of 156 tests over the limit
- Clare County — #54, 14.1% of 154 tests over the limit
- St. Clair County — #55, 13.7% of 515 tests over the limit
- Alpena County — #57, 13.3% of 727 tests over the limit
- Gogebic County — #58, 12.9% of 127 tests over the limit
- Kalkaska County — #59, 12.7% of 157 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).
Macomb County radon FAQ
- Is radon high in Macomb County?
- 13.4% of 4,659 home tests reported to the CDC came back at or above the EPA action level of 4 pCi/L — 3.2 points below the Michigan county median of 16.6%, ranking #56 of 83 tested counties. EPA classifies the county as Zone 3.
- Does an older home in Macomb 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 Macomb County numbers come from?
- 4,659 aggregated home tests in the CDC's Environmental Public Health Tracking dataset (CDC EPHT 2008-2017). Median reading: 1.6 pCi/L; the highest recorded test hit 34.3 pCi/L. How we handle the data, including its limits, is documented on our methodology page.
- What's the highest radon reading recorded in Macomb County?
- 34.3 pCi/L — 8× the EPA action level — against a county median of 1.6 pCi/L across 4,659 tests. That spread is the point: neighboring homes routinely test wildly differently.