(This article by Brian Bienkowski of Environmental Health News was originally posted Sept. 26, 2014, and is used here with permission.) A persistent chemical formerly used in Scotchgard still contaminates most fish in U.S. rivers and the Great Lakes despite a phase-out a dozen years ago, a new federal study shows. U.S. Environmental Protection Agency researchers found perfluorooctane sulfonic acid (PFOS) in all of the 157 fish sampled from nearshore waters in the five Great Lakes and in 73 percent from 162 rivers.

Fisherman with a largemouth bass.
The study, the largest of its kind in freshwater fish, suggests that eating bass, trout, walleye and catfish could be a major source of exposure for anglers and their families. The chemical remains widespread in wildlife, people and water around the world. “This just shows that PFOS still dominates. Even though production stopped more than a decade ago, it’s still the main perfluorinated acid in the environment,” said Craig Butt, a Duke University chemist who was not involved in the study. PFOS and other perfluorinated compounds are used in oil- and water-resistant coatings for pots and pans, clothes, paper, carpet and flame retardant foams. The 3M Company, the major manufacturer of PFOS, voluntarily stopped its production in 2002 after scientists discovered that it was building up in water, wildlife and people. Nevertheless, “every single human being we test has levels of PFOS in them,” Butt said. The compound “doesn’t break down in light, it doesn’t oxidize. Once it’s in the environment, it’s not going anywhere.” Most health studies have focused on communities with drinking water contaminated by PFOS. But people are exposed in many ways, said Sarah Knox, a professor and epidemiologist at West Virginia University. “Routes of exposure are multiple — things like linings of food containers, stain resistance sprays, fire-proofing and non-stick cookware,” she said. EPA estimates that “contamination in food may account for more than 90 percent of human exposure to PFOS and PFOA,” and that fish may be a major source of PFOS. “It should be noted that the higher the fish is in the food chain, the greater the concentration of toxic compounds,” Knox said. In the rivers, 25 fish species were tested, with smallmouth and largemouth bass and channel catfish the most prevalent. In the Great Lakes, 18 species were tested, mostly lake trout, smallmouth bass and walleye. The study did not name the rivers, but the sites were mostly east of the Mississippi River. PFOS, a suspected endocrine disruptor, has been linked to low birth weights, reduced immune system function in children and high blood pressure during pregnancy. In addition, a study of about 47,000 people in West Virginia whose drinking water was contaminated by a DuPont plant linked PFOS to changes in liver function, early menopause in women and high cholesterol. Animal studies with rats and mice also have shown that PFOS causes developmental, reproductive and immune system problems. PFOA, another perfluorinated compound, was found in just 19 of the Great Lakes samples and none of the river samples. It has been linked to heart diseasesuppressed immune systems in children and cancers. Despite repeated requests, EPA officials would not allow the scientists who conducted the study to be available for an interview. Of 13 compounds measured, PFOS was detected at the highest levels. In urban river fish, it was measured at 4.8 to 127 parts per billion, and at 1.9 to 80 parts per billion in Great Lakes fish. EPA hasn’t established a “safe dose” of PFOS. However, Minnesota health officials recommend eating only one meal of fish per week if PFOS concentrations are 40 to 200 parts per billion, and only one meal per month if 200 to 800 parts per billion. About 11 percent of the fish samples from U.S. rivers and 9 percent of the Great Lakes samples exceeded 40 parts per billion. Keri Hornbuckle, a professor at the University of Iowa who studies Great Lakes contaminants, said researchers suspect that wastewater treatment plants are an ongoing source of PFCs. The compounds also travel on ocean and wind currents. “The animals with the highest levels of PFOS we know of are polar bears from the Arctic,” Butt said. New compounds have emerged after 3M’s phase-out of PFOS and PFOA, which the company eliminated in 2008. 3M has touted perfluorobutane sulfonate (PFBS) as a safe alternative, and the compound was not found in any of the river or Great Lakes samples. 3M did not respond to repeated requests for an interview. Michael Murray, a scientist for the National Wildlife Federation, said that the key to addressing emerging contaminants in the Great Lakes is to look upstream now before it’s too late. “We don’t want to be dealing with the next round of perfluorinated compounds in five years,” Murray said. “The key is pollution prevention, practices like green chemistry, to reduce the need for these chemicals in the first place. “Because once they’re here, they don’t go away,” he said.

  • FoodSci

    So on the scale of risks & dangers in today’s world, how important is this? Not to say we ought not be watching out for it, but sounds like less than 10% of fish even get to the concern level. Seems like you’d have to eat a lot of fish for any effect.

    • MaryFinelli

      “EPA hasn’t established a ‘safe dose’ of PFOS,” and fish are implicated as being a major source of this hazardous chemical. Not eating fish sounds to be the best way to reduce one’s exposure to it, as well as to a lot of other hazardous substances. There’s plenty of safer ways to obtain all of the nutrients derived from fish, the best way being to obtain them instead through plant sources.

      • Frank T. Lofaro Jr.

        I’ll still eat fish. And push for more regulation of the chemical industry too. People that eat fish are NOT less healthy than those who do, in fact they are more healthy.

        • MaryFinelli

          What is your evidence of that? Eating fish is a needless hazard:

          “Fish is one of the most polluted foods you could put into your body. Because our oceans have become giant dumping grounds for most of our environmental pollutants, fish contain toxins such as DDT, dioxin, mercury, and PCB’s. You are essentially consuming the lifetime’s worth of exposure to these harmful chemicals being collected in its flesh. Further, fish is high in animal protein, which may contribute to chronic disease. Finally, fish do not contain antioxidants, phytonutrients, and fiber which you can find in plant proteins. Omega-3 fatty acids, the type that aggrandizes fish as a health food, can easily be found in plant foods such as walnuts, flaxseeds, hemp seeds, and soybeans.”
          ~ Julieanna Hever, M.S., R.D., C.P.T., The Plant-Based Dietitian

  • riverdivine

    Thank you for passing along this incredibly important- and alarming!- report. Wish we’d hear more relevant reports like in the MSM….