PFAS-related health warnings set to limit summer fun on 18 Michigan waterways
When Kathleen Gut noticed foam collecting at the edge of Van Etten Lake several years ago, she joked that someone had spilled Dawn dish soap in the Oscoda Township lake.
She never connected the substance to decades of training at the nearby Wurtsmith Air Force Base, where they used a firefighting foam that contained what’s now recognized as a pervasive and potentially toxic contaminant.
A retired school counselor from Haslett, Gut became concerned last year as the state began issuing advisories regarding the foam on the inland lake and when she saw a similar substance along the water line near her Lake Huron cottage.
“If you can’t touch the foam and the foam is on the edge of the water, are you going to send your grandchildren out to swim in it?” Gut said.
As summer begins in the Great Lakes State, vacationers such as Gut will have to limit their activities in some Michigan rivers and lakes because of per- and polyfluoroalkyl substance advisories issued for fish and foam on 18 state waterways.
The compounds are a class of chemicals used for decades in firefighting foam, tanneries, metal platers, Scotchgard and Teflon. Scientists have shown associations between PFAS exposure and health risks such as thyroid disease, increased cholesterol levels, and kidney and testicular cancers.
Elevated PFAS levels have led to do-not-eat-fish advisories on six Michigan waterways, limits on fish consumption on another 11 and advisories against touching foam on two inland lakes and three rivers.
The advisories may seem more numerous than in other states, but that’s largely because Michigan is looking for the contaminant while other states haven’t yet begun the process, said Steve Sliver, director of the Michigan PFAS Action Response Team.
“Nobody around the country really is looking at foam yet,” Sliver said. “There’s not even a standard method to collect the foam.”
The state has identified 49 sites throughout the state with elevated levels of PFAS contaminants in groundwater samples in a first-of-its-kind statewide testing. Many of the fish and foam advisories issued correspond to those 49 areas of concern.
Don't touch the foam
The state first began exploring potential concerns about foam when a group of high school students tested some of the material found on Van Etten Lake. The fluffy shoreline piles tested high for several PFAS compounds, including PFOS.
The state has since issued advisories against touching the foam on five waterways: Van Etten Lake, Lake Margrethe in Grayling, the Rogue River in Rockford, the Thornapple River in Grand Rapids and the Huron River that runs through four southeast Michigan counties.
Unlike the off-white or brown foam that may collect naturally in bays and eddies or near dams, PFAS-contaminated foam typically is bright white in color, is lightweight enough to blow inland and often piles up like shaving cream at the water line.
The substance’s unique texture, location and appearance is one of the reasons the state has issued sweeping advisories against touching the material, said Lynn Sutfin, a spokeswoman for the Michigan Department of Health and Human Services.
“Obviously, that’s of concern because that looks like a lot of fun to any child on the beach,” Sutfin said.
Though the foam is not believed to be absorbed through the skin, it's possible a child could transfer the foam to their mouth easily through unwashed hands, toys or food exposed to the substance.
“We’re telling people just to avoid it, that way you can’t ingest it," Sutfin said.
The state has yet to confirm the presence of PFAS-containing foam on other waterways such as Lake Huron, but residents can call if they find foam they suspect is not naturally occurring. The state’s 24-hour pollution hotline is (800) 292-4706.
High fish PFAS levels
Some of the areas where the state has issued advisories for fish with high levels of PFAS overlap with those areas of concern for foam, such as Lake Margrethe, Van Etten Lake and the Huron River.
While Margrethe and Van Etten have limitations on consumption of certain species, the Huron River has a complete ban on eating any species from where N. Wixom Road crosses the Huron River in Oakland County to where the river enters Lake Erie in Wayne County.
Included within the Huron River area of concern are creeks, ponds and rivers in four separate counties: Norton Creek, Kent Lake, and Hubbell Pond or Mill Pond in Oakland County; Ore Lake, Strawberry and Zukey lakes, Gallagher Lake, Loon Lake, Whitewood Lakes, and Base Line and Portage lakes in Livingston County; Barton Pond, Geddes Pond, Argo Pond, and Ford Lake in Washtenaw County; and Belleville Lake in Wayne County.
“That is one of the larger areas,” said Jennifer Gray, a toxicologist with the state health department's Division of Environmental Health. The advisories on the Huron River were prompted by elevated levels in fish and elevated levels in surface water samples, Gray said.
Like the Huron River, other locations have complete bans on eating certain area fish, such as Allen Lake, the AuSable River, Van Etten Lake and Clark’s Marsh in Iosco County; the Beaver Dam Pond and Helmer Creek in Calhoun County; and ponds at 4300 Cannonsburg Road in Belmont.
Limits on annual consumption of fish exist for certain fish caught on sections of the Saginaw River in Bay and Saginaw counties; the Flint River in Genesee, Lapeer and Saginaw counties; Lake Pleasant in Lapeer County; Lake St. Clair in St. Clair, Macomb and Wayne counties; St. Joseph River in Berrien County; the Rogue River and Freska Lake in Kent County; Long Lake in St. Joseph County; and Silver Lead Creek in Marquette County.
How long will it last?
The elevated levels of PFOS in fish were found via testing that started in 2012 in Clark’s Marsh in Oscoda near the former Wurtsmith Air Force Base, where PFAS-containing firefighting foam was used for training for decades, Gray said.
The state has since tested more than 1,300 fish statewide for more than 10 different PFAS compounds, but Michigan officials concentrate their efforts in areas with a known history of industrial contamination, she said. The advisories issued so far have been linked to PFOS, one of the better understood PFAS compounds.
“That tends to be and seems to be the one that bio-accumulates in fish tissue,” Gray said. “PFOS seems to be the one that builds up.”
Like the other areas with fish advisories, the state must first address the source of the pollution leading to high PFAS levels in fish. But even after the source is identified and addressed, removing the chemical from the fish population can take years, Gray said.
PFAS is believed to have a half life shorter than PCBs, which take about 15 years to decrease by half in the fish population, Gray said. The ultimate verdict on the half-life of PFAS chemicals remains uncertain, she said.
“What we know now is the amount of time it takes for a fish to get rid of PFAS is shorter than PCBs,” Gray said, but “we’re still building our data set on PFAS.”
On the Huron River, officials rapidly sought the source of contamination to address increased PFAS levels in fish and the dynamic response serves as a model for addressing the issue in the rest of the state, Sliver said. Still, decades of exposure can't be undone as easily.
“We found them up in Wixom,” Sliver said of the Huron River contaminant source. “And we’ve actually taken those sources down from thousands of parts per trillion down to non-detect. Our expectation is over time you’ll see the concentrations in fish tissue continue to drop.”