Your Body Almanac

Michigan

Long gray winters, lake-effect cold and arsenic in some wells.

Michigan's winters are long, cold and cloudy, which means months of little vitamin D from sunlight. Some areas have naturally high arsenic in groundwater, nine southern counties have high radon potential, and Lyme disease has been spreading into the state.

01

A long vitamin D winter

Michigan lies from about 42 to 47 degrees north. At Boston's 42 degrees, a classic study found winter sun made no vitamin D in skin from November through February, and the gap grows longer farther north. Lake-effect clouds cut winter sunshine further.

SourcesInfluence of season and latitude on the cutaneous synthesis of vitamin D3 (Webb, Kline and Holick, 1988)Vitamin D — Health Professional Fact Sheet (NIH Office of Dietary Supplements)
Get vitamin D from foodDailyEat fatty fish, fortified milk and UV-exposed mushrooms so you are not relying on the sun alone. Ask your doctor about vitamin DYearlyIf you get little sun or few vitamin D foods, ask at your checkup whether testing or a supplement makes sense for you. Spend time outdoorsDailyGet 20 to 30 minutes in a park, yard or green space most days, walking or just sitting.
02

Arsenic in private wells

Michigan has naturally higher arsenic in groundwater in some areas, and you cannot see or taste it. Long-term exposure is linked to cancer and other illness. The state environmental agency recommends every well owner test for arsenic and not use water above 10 micrograms per liter for drinking or cooking.

SourcesArsenic in Well Water (Michigan Department of Environment, Great Lakes, and Energy)Arsenic and Drinking Water (USGS)
Test your private well every yearYearlyIf your water comes from a private well, have it tested by a certified lab at least once a year.
03

Radon in the southern tier

EPA places nine southern Michigan counties in Zone 1, its highest radon-potential category, including Kalamazoo, Washtenaw, Jackson, Calhoun and Hillsdale. Radon is the second leading cause of lung cancer, and homes anywhere can test high.

SourcesEPA Map of Radon Zones and Supplemental Information (US EPA)Health Risk of Radon (US EPA)
Test your home for radonAs neededRadon is invisible and odorless, so a simple test is the only way to know your level. Fix it at 4 pCi/L or higher.
04

Ticks moving in

Michigan is still a low-incidence Lyme state, but the range of Lyme disease in the US has expanded a lot since the 1990s, and Michigan reported about 5.5 cases per 100,000 people in 2022. A tick check after time in the woods is cheap insurance.

SourcesLyme Disease Case Maps (CDC)Surveillance for Lyme Disease After Implementation of a Revised Case Definition — United States, 2022 (CDC MMWR)
Check for ticksAs neededAfter time in grass or woods, check your whole body, shower within two hours and dry your clothes on high heat. Use insect repellentAs neededUse an EPA-registered repellent on exposed skin when mosquitoes or ticks are around.