Radon Risk in Michigan
EPA zone data and CDC radon averages for all 83 counties in Michigan.
Tipper on radon in Michigan
Michigan's statewide average radon level is 2.87 pCi/L, which falls below the EPA's action level of 4 pCi/L. That's a reasonable baseline, but statewide averages can mask significant county-to-county variation. Some parts of Michigan run considerably higher than others.
Looking at the zone breakdown: 9 of Michigan's 83 counties are EPA Zone 1 (high risk), 32 are Zone 2 (moderate), and 42 are Zone 3 (low). That means 11% of the state falls into the highest risk category, counties where the EPA predicts average indoor levels above 4 pCi/L. Use the county list below to find your area and see the most specific data available.
Within Michigan, the spread is notable. Lenawee County has the highest measured average in the state at 7.3 pCi/L. Luce County sits at the other end with 1.2 pCi/L. 16 counties have a measured average above 4 pCi/L. Remember: these are averages. Individual homes can test significantly higher or lower than their county average depending on construction, foundation type, and ventilation.
Tipper's recommendation for Michigan residents: if you haven't tested your home, start there. A short-term test kit costs around $15 and gives you a result in 48 hours. If your home tests at or above 4 pCi/L, a professional mitigation system (typically $800–$2,000 depending on your foundation and home size) will reliably bring levels down.
Sources: EPA Radon Zone Map, CDC Environmental Public Health Tracking Network
Why Michigan's Geology Matters
Michigan's radon risk is concentrated in the southern Lower Peninsula, where glacial deposits overlie carbonate bedrock (limestone and dolomite). The Michigan Basin's geology creates uranium-bearing soils in many areas. The Upper Peninsula, with its ancient metamorphic rock, also has elevated zones. Northern Lower Peninsula and sandy coastal areas tend to run lower.
Radon Disclosure Laws
Michigan's Seller Disclosure Act requires sellers to disclose known environmental contamination, which includes known radon results, but there is no radon-specific disclosure mandate.
State Radon Program
Michigan Department of Environment, Great Lakes, and Energy — Radon
Highest Radon Averages
Lowest Radon Averages
All Counties in Michigan
Click any county to see its full radon data and local contractors.
Showing 83 of 83 counties in Michigan. Zone classifications from the EPA. Average pCi/L from CDC tracking data.
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Contractors
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