PRINTThe plight of the pallid sturgeon
Something’s wrong in Missouri’s rivers. Male fish are carrying eggs, and the cause is uncertain. Is this a fluke of nature or the result of pollution?
April 10, 2008 | 12:00 a.m. CST
For millenia, dating back to the dinosaurs it still resembles, the sturgeon has swum the watery parts of the world. It shrugged off the dinosaurs’ disappearance and yawned through the ice age.
Household products containing potential endocrine disruptors
shampoos
antibacterial soaps
perfume
laundry detergents
pesticides
plastics
antidepressants
The pallid sturgeon and shovelnose sturgeon of the Missouri and Mississippi rivers evolved slowly in the clear, meandering waters of a natural river system. But then that natural environment disappeared. In 1990, the pallid sturgeon became the first fish species of the Missouri River to be listed under the Endangered Species Act. Dams and dikes altered the flow and temperatures of its habitat, and the waters have grown murky with sediment.
That murkiness masks something else.
More than 10 years ago, the Environmental Protection Agency began studying the effects chemicals have on wildlife and humans, and the Columbia Environmental Research Center has been at the forefront of investigation into environmental contaminants. Diana Papoulias, a fish biologist at CERC, began studying the reproductive effects of sturgeon in 2002. Little was known at the time, so she and her colleagues went out on the Missouri River and collected samples of sturgeon near Hartsburg and Boonville with a goal of obtaining 15 males and 15 females. They came back with something totally different.
“We found intersex individuals right from the start,” Papoulias says.
What she found is described as feminization, such as fully developed eggs in male reproductive organs. Papoulias’ research isn’t unique. For 15 years, biologists have reported similar findings in fish and amphibians around North America. Frogs in Minnesota, alligators in Florida and carp in Nevada have shown intersex abnormalities.
Some scientists blame this sexual identity crisis on the tiny chemicals that permeate our planet. Plastics and pesticides are ubiquitous; personal care products and pharmaceuticals find their way into the watershed through wastewater treatment plants and runoff. A 2002 study by the U.S. Geological Survey detected a wide range of industrial, agricultural and residential chemicals in 80 percent of the 139 streams it sampled. Persistent organic pollutants such as polychlorinated biphenyls circle the globe and have been detected in polar bears.
As reports of wildlife abnormalities pile up, research is zeroing in on a group of chemicals known as endocrine disruptors. These chemicals can mimic hormones when they enter the body. They then interfere with the endocrine system, which relies on the body’s hormones to control vital functions including growth and development. Precisely how many of the more than 80,000 registered chemicals are endocrine disruptors is unknown, but the potential list of products containing them is long: replacement hormones, antidepressants and steroids; shampoos, antibacterial soaps and perfumes; laundry detergents, pesticides and plastics.
These chemicals, of course, are just some of the pollutants we recklessly spew into the environment, and the feminization of fish is only a small portion of a larger problem. But just as the endocrine system is one part of the body — of fish, frogs and folks — humans are part of a larger, interconnected system with several functional parts. It’s easy to think the birth control pills we pop or the soap we shower with disappears or that the fertilizer we use to make our perfectly manicured lawns a glistening green runs off into oblivion. Like the proverbial butterfly flapping its wings, however, there is a ripple effect. Sooner rather than later, the products we consume will sneak their way back into the watershed — back into the rivers and streams where fish swim and back into the water we drink.
DISSECTING THE DEBATE
The cause of these wildlife abnormalities is a matter of much debate, and the usual suspects — environmentalists and industry— are lining up on opposite sides. It’s difficult to isolate the effects of endocrine disruptors in the lab, and the natural environment of wildlife is laced with a mix of compounds. For every study that fingers chemicals as the culprit, industry groups including the American Chemical Society produce research challenging these conclusions.
Bill Herz, the vice president of scientific programs at the Fertilizer Institute, a Washington-based trade association, says the institute has sponsored comprehensive ecological and toxicological studies of the top 23 chemicals used to make hundreds if not thousands of fertilizers. He questions the science that claims chemical nutrients are behind feminization. “Some research indicates nutrients may be involved, but I would say quite honestly we’re highly skeptical of those conclusions,” he says.
It was the 1996 release of Theo Colborn’s eye-opening book Our Stolen Future that brought widespread attention to the potential threat of environmental contaminants. Almost immediately, the science behind the book was attacked by the chemical companies, and ever since, industry-sponsored studies have been unsuccessful in replicating the book’s findings. The long arm of industry has even found its way into Columbia. For years, researchers at MU have been studying bisphenol-A (BPA), a common chemical used to make plastics soft. The Center for Disease Control demonstrated how common BPA is when it found the chemical in nearly 93 percent of people sampled in the U.S.
Researchers at MU’s Endocrine Disruptor Group have published numerous studies that say BPA can mimic estrogen and cause a host of health problems in lab animals.
Wade Welshons, an associate professor of biomedical sciences at the MU College of Veterinary Medicine, says around the time it began publishing its studies, the chemical industry hired the Weinberg Group, an international scientific consulting firm in Washington, D.C. This same product protection group also represented Philip Morris during its secondhand smoke campaign. “There’s almost nothing (the chemical companies) say that has validity anymore scientifically,” he says.
The concept of low-dose effects — meaning that trace amounts of these chemicals can cause trouble — is one of the key battlegrounds in the debate. Typically, toxicologists start testing high doses of a chemical and work down until effects disappear in order to determine a “safe” level of exposure.
But endocrinologists argue for the opposite approach when dealing with the delicate endocrine system. “You have to start at a low concentration and then come up in order to pick up the number of endocrine effects that these chemicals have,” Welshons says.
The argument continues as some biologists worry that these endocrine disruptors could cause declines in fish populations. Between 2001 and 2002, a team of American and Canadian scientists intentionally introduced a potent synthetic estrogen into a Canadian lake and observed the effects on fathead minnows. Within two years, the population collapsed.
DOWN THE DRAIN
As evidence mounts, it seems clear that something in our water is affecting wildlife. The nation’s water quality, of course, has come a long way since the passage of the Clean Water Act in 1972. Regulation has clamped down on pollution discharged directly into streams and rivers. But now concern turns toward nonpoint pollution sources such as farm runoff and storm water, which are much tougher to regulate. When rains come, the herbicides, pesticides and fertilizers used on farms and lawns run back into the watershed, as does runoff at construction sites. According to the EPA, nonpoint pollution is the main source of water quality problems.
Under the Clean Water Act, states are required to identify rivers and streams that do not meet water quality standards. The Missouri Department of Natural Resources currently lists stretches of Hinkson Creek as impaired. The source of pollution? Urban runoff. The pollutant? Unknown.
The Clean Water Act attempted to address urban runoff through its National Pollutant Discharge Elimination System. Any time somebody discharges water with contaminants, it must obtain a permit from the state’s Department of Natural Resources. The city of Columbia reviews storm water permit applications and then forwards them on to the state.
That’s where Jim Thaxter and his inspectors at Columbia’s Public Works Department come in. “We know when the state issues a permit,” Thaxter says. “Once that’s done, we have inspectors at construction sites from the time they start.”
Compliance and enforcement of the permits are overseen by the city, the DNR and the EPA, though they do rely on citizens to report any problems. It was citizen complaints that led the EPA to order The Links at Columbia, the golf course and apartment complex in the northeastern part of the city, to take action in August to reduce runoff from its construction site. The EPA said sediment was running into Hominy Branch, which ultimately feeds into the impaired Hinkson Creek.
The system worked in the case of The Links, but Irene Crawford, director of the DNR’s northeast regional office, notes the difficulty of examining every site with a permit. “Compare the number of water pollution staff statewide to the number of permits,” she says, “and you realize we can’t get to them all.”
That would be a tall order. According to the EPA’s enforcement and compliance database, 181 storm water permits have been issued for Columbia; only 11 have had visits from the EPA.
The public, then, plays an important role in monitoring our waters, and Columbia is encouraging residents to take an active role. Mona Menezes is the storm water educator for the city of Columbia and provides education and outreach on the issue. Menezes oversees stream cleanups and the volunteers who put down the “Dump No Waste … Drains to Streams” decals that dot the town.
She acknowledges that “for most of us, storm water is not compelling, but it is important.” So she meets with residents, businesses and students to inform them how to keep pollution from heading down the drain and into our streams. Menezes notes that the Flat Branch renewal was citizen-led and urges residents to help with the long process to restore Hinkson Creek. “We have to get there one year at a time.”
Columbia’s citizens have responded; Menezes says 336 volunteers helped clean up streams last year. But the city must also rely on the federal government to respond to what Menezes and her volunteers can’t pick up.
Barry Kirchhoff, supervisor at Columbia’s water treatment plant, says endocrine-disrupting chemicals are on the city’s radar as a potential problem. But the city doesn’t monitor for them because they’re not regulated, and Kirchhoff says all water regulations that exist come from the national level. And before that happens, the EPA must answer the two questions in Kirchhoff’s mind: Are they present, and are they significant?
If history is any guide, the EPA might not have an answer anytime soon. Under the 1996 Food Quality Protection Act, Congress ordered the EPA to develop an animal-screening program to see if chemicals in pesticides had the potential to interfere with the endocrine system in people. It was supposed to start the program within three years, but in 1999, the Natural Resources Defense Council sued the EPA for missing the deadline. Testing on 73 chemicals is set to begin this year.
A MURKY FUTURE
There is enough data to suggest the synthetic materials used in almost everything we purchase could be harming the natural world. As biologists continue to study how environmental contaminants affect wildlife, concern is growing over the scope of the problem. More than 10 years after being instructed by Congress to do so, the EPA is finally asking: Could these same chemicals affect us?
People are perhaps less vulnerable than fish, but we do seem to be swimming in our own toxic stew. From the moment we wake up, we wade through a chemical world. At the end of the day, however, we can’t blame the products put out by the chemical companies; they make them, and we take them.
But we can question whether to assume a chemical is innocent until proven guilty. Under the scientific method, scientists can support a hypothesis but never provide absolute proof, and it appears industry is taking advantage of this.
Perhaps the consequences of inaction should be considered as the EPA begins a lengthy and expensive screening process to determine threats to humans and wildlife. Not too long ago the debate over global warming raged; today, the conversation is about how to stop it, not whether it exists. It remains to be seen if we waited too long.
Questions about our chemical world linger, but perhaps the most important belong to Papoulias. Even she cautions against snap judgments about what she found inside those shovelnose sturgeon, a species that survived the Ice Age. Yet the eggs she found inside male fish make her wonder. “Is this an indicator of something to come? Will we see population collapse?
“Or is it an indicator of something even more insidious?” V
