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Concerns grow about hormone-disrupting chemicals in Wisconsin waters The state lags behind Minnesota in testing its lakes and rivers.

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Wisconsin’s Department of Natural Resources and Department of Health Services warn residents to limit their consumption of wild fish to prevent possible health problems from chemical contamination, as do many other states.

Those problems include a range of health effects, but the four groups of chemicals that trigger consumption advisories — PCBs, mercury, dioxins and PFOS (perfluorooctane sulfate) — have been associated with endocrine disruption, DNR toxicologist Candy Schrank confirmed.

Most fish contain at least low levels of mercury, while the other three chemicals are of most concern at specific locations.

Chemicals to blame

Mercury: A natural element that is mobilized and emitted into the air via combustion and other activities. Mercury has been shown to affect the cognitive thinking, memory, attention, language, fine motor skills and visual spatial skills of children exposed in the womb. It can reduce fertility in people and have other reproductive effects, and is associated with nervous system effects in adults. Most people have blood mercury levels below that which is associated with possible health effects.

PCBs: A group of very persistent chlorinated chemicals that build up in the body over years. Researchers saw developmental disorders and cognitive deficits in the children of Michigan mothers who ate moderate to high amounts of fish before and during pregnancy. By 11, these children were three times more likely to have low verbal IQ scores, twice as likely to lag behind at least two years in reading comprehension, and had more difficulty paying attention. Hormones may be the mechanism for these effects, even though they are not usually thought of as endocrine-related. PCB health effects of concern to adults include diabetes and thyroid disorders, both of which are endocrine-related.

EPA: Most people have dioxin levels that are “uncomfortably close to levels that can cause subtle adverse non-cancer effects.”

Dioxins: A family of toxic chemicals that are byproducts from combustion and industrial chemical processes. The state advises not to eat fish when samples exceed 10 parts per trillion; this means no carp or big catfish from the Wisconsin River. Most people have detectable levels of dioxins at levels that are “likely to result in an increased risk of cancer and is uncomfortably close to levels that can cause subtle adverse non-cancer effects,” the U.S. Environmental Protection Agency says. Non-cancer effects include changes in hormone systems, altered fetal development, reduced fertility, and less resistance to disease. Triclosan, a common hand soap ingredient, has been found to break down into dioxins.

PFOS: One of several perfluorinated chemicals made for firefighting foams, paper, pesticides, cleaning products, textiles and other industrial uses. PFOS has been shown to affect the neuroendocrine system and lead to tumors in rats’ livers; rodent studies have also raised concerns about developmental and reproductive effects. Human studies have been limited, however.

How fish consumption advisories work

DNR can test fish for chemicals it suspects are present and will build up in fish. The agency works with Department of Health Services toxicologists to evaluate whether the chemicals appear to pose a risk to people or wildlife. The agency is also working with EPA’s Great Lakes Fish Monitoring and Surveillance Program to screen fish for chemicals of emerging concern, such as the flame retardants known as PBDEs that may be endocrine disruptors.

The nonprofit Wisconsin Center for Investigative Journalism ( collaborates with Wisconsin Public Radio, Wisconsin Public Television, other news media and the UW-Madison School of Journalism and Mass Communication. All works created, published, posted or disseminated by the Center do not necessarily reflect the views or opinions of UW-Madison or any of its affiliates.

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Kate GoldenMultimedia director and reporter

Kate Golden, multimedia director and reporter, specializes in environmental stories and data visualizations.

2 replies on “Tainted fish”

  1. Keep in mind: The Wisconsin DNR has always been EXTREMELY reluctant to publicize fish consumption advisories that are as strong as they should be. The sale of fishing licenses is a substantial source of their funding, so DNR staff are afraid of endangering their own jobs by scaring people away from fishing.

    I remember many times over the years when local environmentalists like me had to push HARD on the DNR just to get them to print enough copies to match the number of licensed anglers in our area, but even that was far removed from guaranteeing that anglers actually SAW any of these copies. The distribution of advisories was spotty at best and unverifiable.

    For years, we pushed for warnings to be printed inside the fishing regulation book that each license holder received annually, to make sure everybody received it … but the DNR refused. (Does anyone know what Scott Walker’s DNR does now? These things always need to be monitored…)

    Even if anglers receive advisories, they don’t realize how thoroughly politicized and weakened the warnings are. Anglers aren’t getting the full story or TRUE risk warnings.

    The DNR isb’t the only, or even the biggest, obstacle to public awareness. Publicity about health risks from fish consumption has also been heavily stifled by the tourism industry, charter fishing businesses, commercial fishermen, marinas, bait shops, sporting goods retailers, grocers, restaurants, hotel operators, local governments, municipal wastewater dischargers, corporate polluters, and other economic sectors with a financial stake in “good fishing.”

    Elected officials of both parties have also been leery of ( and likely warned against) making an issue of fish contamination.

    The medical establishment never says anything either … so that leaves a few scattered environmentalists as virtually the only outspoken advocates for full public awareness of all likely health risks.

    But who listens to environmentalists?

    Well-funded and carefully-orchestrated corporate disinformation campaigns have been trashing environmentalists for several decades, so now even environmentalists often refuse to be called “environmentalists” or be seen associating with “wacko extremists.”

    So who’s left to warn the public?

  2. BTW — Concerns about flame retardants are NOT just an “emerging” concern.

    PBDE’a have been a MAJOR concern in many scientific, health and environmental circles for well over a decade already, but these compounds are still being produced in MASSIVE quantities and have been incorporated in a multitude of everyday products that most of us use every day.

    I remember attending one scientist’s presentation about PBDE’s in the Great Lakes (particularly Lake Michigan) at least 10 years ago. During his talk, he kept adding this aside: “… and did I mention that this is a very large and powerful industry?”

    He was warning everyone in the room that it would be a long, difficult, uphill battle to reduce or eliminate public use of PBDE’s, and a potentially risky issue for scientists to research, publicize or (…heaven forbid…) tackle in the public policy arena. These are PROFITABLE compounds, so he was strongly hinting that big producers would fight legal restrictions every step of the way, using all tools at their disposal.

    For EPA and DNR to STILL be calling PBDE’s “an emerging issue” is not a good sign. It means all of us may be forced to wait another decade or 2 before adequate regulations are in place, and by then it may be too late for several generations of us. The billions of pounds of PBDE’s already produced and released into the environment by then could continue circulating in our food, water, soil and air for another 100 years and probably longer, because PBDE’s are as persistent as their closely related chemical cousins, PCBs and Dioxins, and are likely to pose similar health risks due to their similar chemical structures.

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