PFAS in Michigan fish raise health concerns, questions
Bright and early in the morning at a garage south of Lansing, a team of state officials is faced with more than a hundred rainbow smelt, lined up neatly on a metal table.
The little, silver fish were caught this year from Big Twin Lake in Kalkaska.
The researchers move quickly to grab a tiny fish, chop its head off and gut it. As they work, they call out the length, weight and sex of each fish.
Decapitating and gutting is one of the more common ways to prepare smelt, but the team has no intention of making or eating any pan-fried smelt.
Instead, the processed fish will be sent to the state’s health department, where they’ll be tested for contaminants.
“Overall, we look for mercury, PCBs, PFAS, pesticides like DDT. Certain instances we’ll look for different metals like lead,” Brandon Armstrong said.
Armstrong coordinates the fish contaminant monitoring program with the Michigan Department of Environment, Great Lakes, and Energy (EGLE).
On average, his team collects 1200-1500 fish every year.
“Historically, we would collect fish all summer, and then we just have a series of fillet days in the winter," Armstrong said. "That was 10 years ago when we were only looking at 20 sites across the state, and now we're up to 70 this year.”
The program started in the 1980s, initially to investigate specific areas of contamination, like the Pine River in St. Louis, Michigan, where Velsicol dumped industrial waste, and fish still have high levels of the pesticide DDT.
Today, the state catches and tests fish in waterbodies all over to track changes in contaminant levels, gauge water quality and develop fish consumption guidelines.
But the contaminants-of-the-hour are PFAS, a group of ubiquitous chemicals associated with increased risk of certain cancers, decreased fertility and developmental issues in children, among other health effects.
Armstrong said PFAS are a unique and challenging class of chemicals to work with.
"[There are] lots of curveballs thrown at us," Armstrong said. "Like with the smelt we just processed, smelt are a relatively short-lived species that feed low on the food chain. But for whatever reason, we’re seeing high PFAS concentrations in them.”
Some studies reported these “forever chemicals” in every fish sample collected from the Great Lakes. And as the levels of what’s considered safe in drinking water, drop into a lower, nearly undetectable, range, some researchers are raising the alarm of what the high toxicity of PFAS means for Michigan fish.
“The science is continuing to evolve at a rapid pace because it's on a lot of people's minds,” said Kevin Cox, a toxicologist with EGLE.
Cox said developing health guidelines for fish is tricky, since there are many factors that can affect PFAS levels in fish and humans.
There's also significant variation of PFAS levels within a single lake and between different fish, with the potential for bioaccumulation, biomagnification and offloadingPFAS to offspring in certain species.
“In real world exposure, a lot of people are getting exposed, not just to one compound at a time, but to mixtures, and so there's questions about that," Cox said.
Although the state tests for nearly 40 PFAS compounds, Michigan’s fish consumption guidelines focus on just one type of the chemical, known as PFOS. The guidelines advise people to limit their consumption if levels go above 9 parts per billion (ppb) in fish samples. That’s like nine teardrops in a swimming pool.
If PFAS levels hit 300 ppb, the state issues a “do not eat” advisory for an impacted fish in a specific river or lake.
“There’s still a lot of things we need to understand about PFAS and how it operates, but we also want to do our best to make sure we're being as protective as we can,” Cox said.
The guidelines are advisory only, they’re more like recommendations for anglers and fish consumers.
The Michigan Department of Health and Human Services said guidelines are reviewed routinely, based on the best available science. But other fish regulations, like in the European Union, set exposure safety limits down to 2 ppb.
A recent study from Duke University and the Environmental Working Group suggests that eating even a few servings of freshwater fish may be on par with drinking PFAS-contaminated water for a month, or longer. The authors of the study did not respond to WCMU's request for comment.
“Get all the information and data you need, and give us the bad news, whatever that is," said Joe Hemming, with the Anglers of the Au Sable. "We’re going to have to live with it and deal with it.”
In the lower Au Sable in Iosco County, the state has “do not eat” advisories on fish like bluegill and bass, due to high PFAS levels. They suggest limited servings on other species.
Hemming said he can’t look at PFAS as “just another contaminant.”
“I know [the state doesn't] fully understand its effects, but we’ve got to err on the side of caution when we're talking about this," Hemming said. "And the fact they're called forever chemicals, that's pretty disconcerting.”
Hemming said it’s not only about fish, they’re just the “canary in the coal mine.”
“Nobody should be foolish enough to think that it just stops at fish and doesn't go further up the food chain," Hemming said. "It's a big indicator of what a huge problem we have in the environment.”
In Lansing, EGLE officials move on to processing brook trout. They've finished up with the rainbow smelt, whose consumption guidelines were recently updated to account for PFAS in seven lakes.
According to Brandon Armstrong, with EGLE, it's not all bad news with PFAS. Despite the chemicals' prevalence in fish, the EPA reports that levels are dropping overall. But there are still concerns about PFAS bioaccumulating and fish offloading contaminants to their offspring.
Armstrong said in places like Kent Lake and the Flint River, PFAS levels in fish are still high, but after the source of contamination was shut off, the state saw a decrease in levels.
On the flipside, Armstrong said he's unsure if fish will ever be taken off the "do not eat" advisory in places like Clark's Marsh and Van Etten Creek in Oscoda, where the old Wurtsmith base continues to bleed PFAS.
Whether the state changes the PFAS fish guidance remains to be seen, but the work isn’t over. More fish, more lakes, more streams and more contaminants are on the to-do list.
For more information on PFAS guidelines on Michigan fish, visit the state's Eat Safe Fish program.