Minnesota is the land of 10,000 lakes. And in those 10,000 lakes, you can find at least 56 different industrial and pharmaceutical chemicals.
According to a report issued in 2013 by the Minnesota Pollution Control Agency (MPCA), the state’s famous waters contain a witch’s brew of poisons, drugs and endocrine disruptors.
One of those lakes—Lake Nokomis —is a “popular” recreational spot in the Minneapolis area. The lake, named in honor of Hiawatha’s grandmother, offers local residents a chance to go “fishing downtown ” for Bluegill, Crappie, Northern Pike, Largemouth Bass, Walleye and White Sucker.
It also offers a variety of antibiotics, chemicals and PPCPs (pharmaceuticals and personal care products). As the Wisconsin Center for Investigative Journalism reported , tests on the lake found “a component of plastic, an antibacterial soap ingredient, an antibiotic used on swine, a breakdown product of cocaine, an antidepressant, a fungicide and a drug used to treat Parkinson’s disease.”
In fact, a statewide survey by the MPCA revealed the presence of a staggering variety of “unregulated chemicals” from personal care products, pharmaceuticals and plastics, all mixed in with the usual poisonous suspects—pesticides, herbicides, pig antibiotics and, most ubiquitously, an insect repellent (DEET).
Although most of the chemicals were found in “trace amounts” in 47 of the 50 lakes and rivers tested, one official at the MPCA was circumspect about the findings, “What these studies really are measuring is the footprint of our society and how we live,” said MPCA Commissioner John Linc Stine . “Our lakes and rivers are reflecting the chemicals we use and put into our bodies.”
And what we are putting into our bodies isn’t good. A 2013 report by World Health Organization and the United Nations Environment Programme deemed endocrine disrupting chemicals and hormone disruptors a “global threat.” Among the cited endocrine-related problems on the rise are:
Large proportions of young men with “poor semen quality.”
Genital malformations like “non-descending” testes and penile malformations.
Endocrine-related cancers (breast, ovarian, prostate, testicular and thyroid).
Early onset of breast development in young girls.
Global rise in the prevalence of obesity and Type-2 diabetes.
And that is just a small sample of the likely complications caused by chemicals dumped directly into the environment and, as was pointed out by the Minnesota study, what people expel back into the water upon which all life depends.
It’s the 21st Century’s post-modern take on the water cycle. Humans drink more and more “clean” water from BPA-bleeding bottles , take a dizzying array of anti-depressants and painkillers , and use billions of dollars worth of cleansers, shampoos, micro-beaded soaps and exfoliators . All of it goes down the drain, often passing through people’s personal plumbing before entering municipal sewage systems. From there, treatment systems flush back out into the environment what we first flushed out of our bodies.
Eventually, it will all cycle back, particularly as water becomes more and more scarce and these tainted waterways are tapped to quench the insatiable thirst of growing populations. Even worse, this growing demand intersects with water scarcity caused by climate change-related droughts , by toxic spills , oil exploration and hydraulic fracturing , and by the loss of major underground aquifers to overuse and chemical contamination. While we are just beginning to see the full impact of this wicked water cycle upon humans, the impact on fish is clear.
A new study published in Environmental Health Perspectives found a possible link between estrogenic compounds in the environment and heart valve development in zebrafish. Scientists exposed zebrafish embryos to water samples pulled from 19 river sites in Pennsylvania and Virginia. Of those, 16 of the water samples triggered estrogen receptors in the developing heart tissue of the embryos. That unusual response—which is known in liver cells, but not previously seen in heart cells —indicated the presence of hormone-mimicking chemicals in the waterways. It also indicated a DNA-related response to these chemicals.
One of the authors of the study told Environmental Health News , “We don’t know yet in this case what’s in the water, what the bioactive ingredient is…but we know from the lab that if we add a synthetic estrogen like BPA, or a natural estrogen, both of those preferentially target the heart valves.”
Mark Ferrey, the Pollution Control Agency researcher who conducted the two studies on Minnesota’s waterways said the results there “…suggest that PPCPs (pharmaceuticals and personal care products) and endocrine active chemicals are widespread in lakes and rivers, and that fish are likely altered on genetic, cellular, organism, and population levels when exposed to the chemicals that find their way into surface water from a variety of sources.”
One fish population in Ontario, Canada is a case in point. Or, more precisely, was a case in point. Beginning in 2001, scientists conducted a study on a lake full of fathead minnows. They “spiked” the lake with a synthetic estrogen used in birth control pills at levels consistent with those discharged by most sewage systems . It didn’t take long before the fish became “feminized”—males became indistinguishable from females, producing eggs instead of sperm and threatening the reproductive cycle. Within a few years, the entire population had collapsed.
Fortunately, this isn’t a problem entirely without a solution. Unlike the intentional exposure of the Canada’s fathead minnows, fish populations downstream from wastewater discharge into Boulder Creek, Colorado were succumbing to feminization due to “chemical contaminants that act as hormone disrupters ” passing out of people and into the water. So, in 2008, the city of Boulder upgraded its wastewater treatment plant and, by 2010, a University of Colorado at Boulder study found that “male fish are taking longer to be feminized.”
Longer is better, but it may not be enough. Professor David Norris, the author of the study, was not particularly sanguine the solution : “This is not the problem of water treatment plants; it’s our problem as human beings. We excrete natural and synthetic estrogens and use shampoos, detergents and cosmetics containing a variety of hormone disrupters that wind up in waterways. All of these different chemicals we are putting into the environment have the potential to alter the biology of animals and to affect ecosystems.”
Ultimately, understanding the full impact of this “chemical soup” is the key to regulating PPCPs, hormone-mimicking chemicals and endocrine-active compounds (EACs). Until recently, chemical safety studies focused on direct, one-to-one links between a specific chemical and a specific outcome—like the fathead minnow study in Canada. But chemicals often mix with the other chemicals in trace amounts—as is the case with Minnesota’s lakes. This creates a “cocktail effect” that makes it hard to find direct links.
So, Robert Tanguay at Oregon State University is testing various chemical combinations on schools of zebrafish in his EPA-funded lab . Thousands of consumer products are being mixed and exposed to zebrafish, like those in the estrogen study. Tanguay’s data reflects the long-ignored impact of chemical interactions on all species. His data cannot come too soon. Research now illustrates the epigenetic effect of chemical exposure —showing genetic mutations being handed down from one generation to the next.
Alas, a spoiled, poisonous Lake Nokomis isn’t the only thing we risk handing down to the next generation.
Photo: "A young fisherman holds up his first Walleye catch of the day," via Shutterstock .