The Michigan Department of Health and Human Services is advising residents to avoid foam on streams, rivers and lakes.
Health officials say foam may contain PFAS.
PFAS are a group of industrial chemicals that don't break down easily.
Marcus Wasilevich is the toxicology and assessment section manager in the state health department's division of environmental health. He said some kinds of the chemicals have been linked to health problems.
"An increased risk of certain health (issues) such as liver damage or thyroid disease, decreased immune system response to vaccines, higher cholesterol, reduced fertility or some of them have even been linked to developing certain types of cancer such as kidney or testicular cancer," he said.
Health officials note that foam containing PFAS tends to be bright white in color and lightweight and it can pile up along shores or blow onto beaches.
MDHHS says, "Natural foam without PFAS is usually off-white and/or brown in color, often has an earthy or fishy scent, and tends to pile up in bays, eddies or at river barriers such as dams."
The health department recommends avoiding contact with foam, but says if you do have contact, you should bathe as soon as you can.
