Anglers in Montana now need to be extra careful about which fish they consume and how much. A new study from multiple state agencies showed that certain fish are high in PFAS, or so-called forever chemicals, which pose risks to human health.
What Are PFAS?
PFAS are a kind of manmade chemical. They became popular in the 1950s, and were used for everything from nonstick cookware to pesticides to waterproof jackets.
To make PFAS, scientists replace the hydrogen in an organic molecule with fluorine. The fluorine bonds very strongly to the carbon, making them slow to degrade, which is where the term “forever chemicals” comes from.
For years, researchers have documented the potential negative health effects of PFAS on humans. They include increased risks of certain cancers, a lowering of the immune system’s ability to fight infections, delayed onset of puberty in girls, evidence of liver damage, and increased risk of childhood obesity.
The Study
Back in 2020, the state of Montana saw PFAS as an increasing area of concern and began the Montana PFAS Action Plan. In 2023, the Montana Department of Environmental Quality partnered with Montana Fish, Wildlife, and Parks to conduct research into how widespread the contaminant might be.
They selected 14 sites across nine bodies of water that were: A) shown to have levels of PFAS in the past or thought to be at-risk of contamination; and B) were popular or important fishing areas. They selected samples of fish that were widespread in each area, including yellow perch, rainbow trout, and walleye. Researchers tested a total of 50 tissue samples for 40 different kinds of PFAS.
The Results
The results of the study show how widespread PFAS are in these fish populations. Of the 50 samples, 39, or 78%, tested positive for at least one PFAS. Scientists were able to tell which areas had the most contaminated fish. Walleye in the Fort Peck Reservoir, for example, contained 5.4 micrograms of PFOS, a kind of forever chemical, per wet weight.
The study tested fish, and not just the water itself, because the levels of chemicals can vary. “PFAS accumulates in fish tissue over time as they are repeatedly exposed. Waterbodies with confirmed or potential PFAS sources in their watershed may show higher PFAS levels in fish tissue than in the surrounding surface water,” the study explained.
In light of these findings, the Interagency Fish Consumption Advisory Group released updated recommendations for fish consumption in the state. The guidelines suggest that certain populations not eat certain species and sizes of fish from certain areas due to PFAS contamination. For example, women and children should not consume any amount of brown trout from Prickly Pear Creek. In other cases, the agency makes more carte blanche recommendations, like saying that no one should eat any species of fish caught from the Bitterroot River to the Flathead River.
Why Does It Matter?
Several other states, including North Dakota, have found similar issues with PFAS in fish. The increased spread of PFAS thus lowers our ability to consume and live off of what we catch.
PFAS have long been a thorn in the outdoor industry’s side. For years, manufacturers of waterproof jackets, water-repellant sleeping bags, and tents relied on these chemicals. With increased awareness about the potential danger of these materials, many brands have switched to sustainable, PFAS-free materials.
The damage, however, is already done. These chemicals can take up to 1,000 years to break down, so once they’re in waterways and the ground, we must live with their potentially devastating health effects for centuries.
Read the full article here