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LANSING, Mich. – As the summer months approach, the Michigan Department of Health and Human Services (MDHHS) is issuing its annual recommendation that Michiganders should avoid contact with the foam they may see on Michigan water bodies such as lakes, rivers, and streams. Many people ask what causes foam on lakes, one possibility may give you pause before you take a swim this summer
What Causes Foam on Lake Water?
The foam may have unknown chemicals or bacteria in them, so it is recommended to avoid contact. Foam can form on any water body, but some water bodies may have high levels of per- and polyfluoroalkyl substances (PFAS). PFAS-containing foam tends to be bright white in color, is often lightweight, and may pile up like shaving cream on shorelines or blow onto beaches.
Naturally occurring foam without PFAS tends to pile up in bays, eddies or at river barriers such as dams. Naturally occurring foam is typically off-white and/or brown in color and often has an earthy or fishy scent.
If contact with foam is made, take care to rinse or wash it off as soon as possible, particularly if PFAS contamination is suspected in the waterbody. The longer foam remains on the skin, the greater the chance of accidentally swallowing the foam or the foam residue left behind.
“Although current science shows that the risk of PFAS getting into your system from contact with skin is low, you can minimize exposure to PFAS by rinsing or showering after you are done with your recreational activities,” said Dr. Joneigh Khaldun, chief medical executive and chief deputy for health at MDHHS. “In general, washing hands and rinsing off after recreating will help to protect people from chemicals and bacteria that may be in water bodies.”
PFAS are emerging contaminants, and the state is working to identify all water bodies that have been affected. Health advisories have been issued for specific waterbodies where PFAS-containing foam has been found in the past. These specific advisories can be found in the “PFAS Foam on Lakes and Streams” section of Michigan.gov/PFASResponse, under “Testing.” MDHHS evaluates surface water and foam data as available and will issue future advisories as needed.
MDHHS’ recommendation to avoid foam on waterbodies is for people of all ages, including young children. An MDHHS evaluation suggests young children could have PFAS exposure that may increase their risk of negative health effects if they have repeated contact with foam containing high amounts of PFAS for a few hours a day throughout the recreational season. Contact with surface water, including swimming or other recreational activities in water bodies containing PFAS, is not a health concern. PFAS-containing foams typically have a much greater concentration of chemicals than what is found in the water itself.
Dogs At Risk Too
The Michigan Department of Agriculture and Rural Development also recommends that people do not allow their animals – especially dogs – to come into contact with or swallow the foam. Dogs and other animals are at risk of swallowing foam accumulated in their fur when grooming themselves. All animals should be thoroughly rinsed off and bathed with fresh water after coming into contact with PFAS-containing foam. Pet owners with questions related to their animals and foam ingestion should contact their veterinarian.
This PFAS Foam recommendation comes on the wake of an investigation by the DNR that a parasite, not poison, caused swan death on a Michigan inland lake.
More information on PFAS-containing foam can be found under the “PFAS Foam” section at Michigan.gov/PFASResponse. If you have questions about exposures to PFAS and/or foam, call the MDHHS Environmental Health hotline at 800-648-6942.
