State: Watch out for PFAS white foam on certain Michigan waterways

If you see bright-white foam piling up along the shoreline when you're swimming, canoeing or fishing this holiday weekend in Michigan, the best advice is to steer clear.

That's especially important on the Huron River and its lakes and ponds in southeast Michigan, or one of four other waterways in the state where dangerous PFAS chemicals — perfluoroalkyl substances — have been found.

In addition to Huron River system, PFAS advisories were issued for Van Etten Lake in Oscoda, Lake Margrethe in Grayling, the Rogue River in Rockford and the Thornapple River in Grand Rapids.

The Michigan Department of Health and Human Services issued the reminder ahead of the busy July 4 holiday that anyone coming in contact with foam should rinse it off or bathe immediately, especially if the body of water is suspected to contain PFAS. Failure to rinse off or bathe can lead to accidentally swallowing foam or foam residue.  

Animals that have come in contact with foam should also be rinsed off and bathed with fresh water.  

“Studies have shown that the risk of PFAS getting into your body from skin contact is low, but you can accidentally swallow PFAS or other chemicals and bacteria if you do not rinse off or bathe after coming into contact with foam,” Michigan Chief Medical Executive Dr. Natasha Bagdasarian said in a statement. “Washing your hands and rinsing off after water activities can protect you from chemicals or bacteria that may be in water or foam.”

PFAS is a widely used, long-lasting chemical that's found in many products including water-repellent coatings, nonstick cooking surfaces and firefighting foam. It has been found in the bloodstream of nearly everyone tested by the Centers for Disease Control and Prevention.

Although its health effects are not fully known in humans, large doses in animal studies have shown it may affect growth and development, the immune system and thyroid function, as well as cause liver damage, according to the CDC.

Not all foam found in rivers and lakes is inherently dangerous. Foam containing PFAS appears to be bright white, lightweight and may pile up along shores or blow onto beaches. Foam not containing PFAS is usually off-white or brown, has an earthy or fishy scent, and tends to pile up in bays, eddies or at river barriers like dams, according to the state.

For more information about PFAS visit www.michigan.gov/pfasresponse/About. 

Mthompson2@detroitnews.com 

Twitter: mackenziethomp