Great Lakes Have Hormone-Mimicking Drugs
Larry Barber has spent 10 years studying water quality and fish health in the Great Lakes Region. He wasn't interested in the contaminants that everyone knows about.
These contaminants are still a problem: PCBs, Mercury... There is a less-known group of contaminants that can have serious and worrying health effects on aquatic animals.
Barber was a researcher geologist at the U.S. Geological Survey. He searched for hormone-disrupting chemicals - known as alkylphenols. These compounds made it through wastewater treatment plants, contaminating rivers in the Great Lakes region and fish in the Upper Mississippi River Region.
They are present in waterways of the Great Lakes basin that get wastewater treatment plant effluent.
Barber explained that it doesn't really matter if the wastewater is coming from a city or an individual tank. "These chemicals exist."
The original purpose of wastewater treatment plants was not to deal with these chemicals, which are widely used commercially as well as residentially in cleaning products, detergents, and adhesives. Operators have to cope with the surge of hormone-mimickings into their plants.
Scientists are concerned that biologically active contaminants (and their metabolites) could alter hormones in fish, causing behavioral, developmental, and reproductive problems.
Alan Vajda, assistant professor of biology, University of Colorado, said, "In terms of effect, these alkylphenols [are] just one subset of compounds which add up to cause adverse effects." "A little estrogenic contraception, a little alkylphenol... it all adds up.
It is almost ubiquitous. From 1999 to 2009, Barber's colleagues searched for nine compounds (and their metabolites) in effluents from wastewater treatment plants in Duluth/St. Paul, Minnesota; Chicago, Detroit, Indianapolis, Akron, Ohio. Many of these chemicals are known to disrupt the hormone system. All nine compounds were found in the effluent of every single plant.
Barber stated that the discharge amount was relatively constant over the course of the study.
These compounds have been found in Great Lakes waters before. Environment Canada in 2007 reported that these compounds had been found in sediment from a Great Lakes coast wetland in Ontario. They also accumulated in local invertebrates.
An additional Canadian study was done in 2009 at 28 sites on the lakes Erie and Huron. It found that alkylphenols are widely distributed in sediments of lower Great Lakes. However, concentrations nearer larger cities were higher.
Vajda stated that alkyphenols "are almost everywhere." There are many places where these compounds can be found, including in agriculture and industrial use.
Researchers don't always look for the parent compound. They are only partially broken down by wastewater treatment plants.
But, these metabolites are still broken down and retain their endocrine disrupting qualities.
Barber stated that many of them are transformed into biologically more active forms after they go through the treatment plants, the sewers and the wastewater treatment plant.
Alkyphenols have estrogenic impacts on fish Alkyphenols interfere with the endocrine system, acting as estrogenic in birds, fish, and mammals.
Vajda stated that estrogens act via the estrogen receptor. The most common impact on health people associate with reproduction. Vajda said, "But there are many roles - estrogens have important effects on the brain, metabolism, and cardiovascular health."
Barber, along with colleagues, tested fish caught in the Great Lakes for evidence of endocrine disturbance. The researchers found that plasma vitellogenin (a protein which occurs primarily in female fish) was most prevalent in male fish, but reduced in females.
Barber noted that responses from both the sexes indicate endocrine disruption.
The endocrine disruption is causing a lot imbalances within these biological feedback mechanisms. Barber stated that estrogen-driven machinery can cause the females to shut down after exposure. The estrogen-exposed male fish will make this protein in their bodies."
When asked to comment on Barber's findings, Tara Johnson, a spokesperson with the U.S. Environmental Protection Agency, said via email: "None of the actual results are particularly remarkable or unexpected based on past studies of this type with alkylphenols."
Researchers have found that alkyphenols can cause a variety of fish-related health problems.
Most of the research has been from laboratory studies, said Reynaldo Patino, a USGS scientist and leader of the Texas Cooperative Fish and Wildlife Research Unit.
"Studies suggest behavior problems, impaired reproduction, development of immune system, disease resistance," Patino said. All of these functions are vital."
For example, Barber, Vajda and colleagues in 2010 found that minnows exposed to hormone- and alkylphenol-contaminated wastewater effluent from Boulder, Colorado, were demasculinized within 14 days.
Vajda explained that Boulder water officials had taken steps to minimize alkyphenols in their effluent during the research period.
He said that the initial demasculinization was caused by alkyphenols.
Michigan scientists discovered severe developmental issues in crayfish exposed to these chemicals.
Research from the UK’s Imperial Cancer Research Fund has shown that four commonly found alkylphenols in trout stimulate gene expression as well as the growth of breast -cancer cell lines.
Vajda said that all of these studies are relevant for the Great Lakes fish since endocrine disrupting compounds should act similarly across fish species. Vajda said that it is difficult to pinpoint any health effects on any particular group of compounds because fish can be exposed to so many.
One of the biggest concerns is how compounds might affect fish populations. It would also be difficult to pinpoint, Patino stated, however it is not unreasonable to suspect that there may be impacts at the population level.
Individual fish are affected by wastewater effluent. Patino explained that it's reasonable to speculate that individuals, and even reproductive endpoints are, may be affected.
All exposures count It's difficult to quantify the risk alkyphenolic-contaminated fish are to humans, said Dr. Ana Soto, a Tufts University professor and biologist, adding that what and how many fish eaten would determine exposure.
But, contaminated water and fish can also be a route to estrogen exposure.
Soto explained that estrogens, such as BPA and BPA are already affecting us. In a nutshell I cannot tell how many people will experience endocrine disruption from eating fish caught in rivers. However, I do know that there are potential risks and all exposures matter.
"Emollients are already present in the body, but there is potential for more to be supplied by the water and fish.
It is important to stop these compounds at their source. Alkylphenols, which are common in wastewater effluent, can easily be stopped because the wastewater treatment plant was not made for such compounds.
Chris Hornback is the senior director of regulatory affairs at the National Association of Clean Water Agencies. He stated, "The fundamental concept of plants was originally conceptualized 70 to 80 years ago.
He explained that the plants are designed to remove the stuff from water. They also clean it up and then return it to its environment . When these concepts were initially conceptualized, nothing could have been imagined other than triclosan and estrogen from birth control pill or alkyphenolics.
Research has shown that there are ways to improve the rate at which these chemicals can be removed. Hornback stated that the best way to remove emerging contaminants such as alkyphenols is by using reverse osmosis. This process cleans water through membranes. Reverse osmosis can be prohibitively costly for many plants.
Others have succeeded in slowing down the time for sludge retention. This keeps wastewater within the area where organic matter is being consumed by organisms. Longer holding periods seem to be more effective in removing alkyphenols. Hornback stated that this is not without its problems.
The overall process can be slowed down, which will impact the amount of treatment you are able to perform. It is not possible to just put a technology on that will remove contaminant "X", he stated.
An alternative option is to activate carbon filters. This was suggested by Larry Rogacki who is the district general manager for support services at Minnesota’s Metropolitan Council Environmental Services. They operate the wastewater treatment plants that serve the St. Paul region and Minneapolis.
Rogacki stated that it would also be extremely expensive. Rogacki explained that these compounds are worth hundreds of millions of dollar. It is better to avoid them from the sanitary sewers in the first instance.
Hornback explained that alkyphenolic chemicals can cause problems in the environment and should be prevented from entering the sewer."The sewer does not contain trash."
For example, Boulder's city officials worked closely with Barber, and other experts to check local waterways for alkyphenols. Then, they reached out to high-alkyphenol concentration industries to inform them of possible impacts.
Hornback expressed concern that the EPA will approve compounds after confirming their environmental impact and force treatment facilities to handle them.
Johnson of the EPA stated that there are no aquatic quality standards or guidelines for human and aquatic drinking water for the chemical substances Barber and her colleagues tested.
She added that standards are not "imminently planned to be developed" at this time.
Barber explained that chemical presence can be reduced by voluntary actions.
"It is important to let people know. When people realise that their products have an unpleasant environmental impact and are aware of alternatives they can choose to use them, it's a common practice for many to switch.