Navigation Links
Fish devastated by sex-changing chemicals in municipal wastewater
Date:2/16/2008

This release is also available in French.

While most people understand the dangers of flushing toxic chemicals into the ecosystem through municipal sewer systems, one potentially devastating threat to wild fish populations comes from an unlikely source: estrogen.

After an exhaustive seven-year research effort, Canadian biologists found that miniscule amounts of estrogen present in municipal wastewater discharges can decimate wild fish populations living downstream.

The research, led by Dr. Karen Kidd, an NSERC-funded biology professor at the University of New Brunswick (Saint John) and the Canadian Rivers Institute, confirms that synthetic estrogen used in birth control pills can wreak havoc on the sex lives of fish. Small amounts of estrogen are excreted naturally by women whether or not they are taking birth control pills.

Male fish exposed to estrogen become feminized, producing egg protein normally synthesized by females. In female fish, estrogen often retards normal sexual maturation, including egg production.

Weve known for some time that estrogen can adversely affect the reproductive health of fish, but ours was the first study to show the long-term impact on the sustainability of wild fish populations, explains Kidd. What we demonstrated is that estrogen can wipe out entire populations of small fish a key food source for larger fish whose survival could in turn be threatened over the longer term.

Kidd and her colleagues reported the findings last year in the Proceedings of the National Academy of Sciences of the United States of America. She is also presenting the research at the prestigious 2008 American Association for the Advancement of Science (AAAS) Conference during a session entitled, From Kitchen Sinks to Ocean Basins: Emerging Chemical Contaminants and Human Health.

Estrogen is part of a broader class of sex-changing chemical compounds known as endocrine disrupting substances. These contaminants, also present in pulp mill effluents, can seriously interfere with normal hormonal processes, notes Kidd, the Canada Research Chair in Chemical Contamination of Food Webs.

To better understand the impacts of estrogen on fish, the researchers conducted a seven-year, whole-lake study at the Experimental Lakes Area in northwestern Ontario. Over three summers, they added tiny amounts low parts per trillion of the synthetic estrogen used in birth control pills to the lake to recreate concentrations measured in municipal wastewater.

During that period, they observed that chronic exposure to estrogen led to the near extinction of the lakes fathead minnow population as well significant declines in larger fish, such as pearl dace and lake trout.

Generally, the smaller the fish, the more vulnerable they are to estrogen, remarks Kidd.

Part of the reason, she adds, is that smaller fish have a shorter lifespan and will often die after reproducing only once.

The researchers used synthetic estrogen because it tends to persist longer in the environment than natural estrogens. Yet the problem with estrogen is not its environmental persistence but rather its persistent discharge in municipal wastewater into surface waters.

Kidd says the risk is greatest for aquatic ecosystems downstream from municipalities that either discharge untreated wastewater or maintain only primary treatment facilities. On the flipside, the problem is of less concern near cities that remove a wide range of chemical contaminants, including estrogens, from wastewater using secondary and tertiary treatment processes.

It is now understood, she says, that removing estrogen through wastewater treatment can reverse the adverse impact of this substance/hormone on wild fish. In fact, three years after halting additions of synthetic estrogen to the experimental lake, the researchers discovered that the fathead minnow population was on the rebound.

To me, thats the good news. Once you take the stressor out the system, we now have ample evidence that suggests affected fish populations will recover.


'/>"/>

Contact: Dor Dunne
dore.dunne@nserc.ca
613-851-8677
Natural Sciences and Engineering Research Council
Source:Eurekalert

Related medicine news :

1. Rohm and Haas to Webcast Presentation at Credit Suisse Chemicals Conference
2. National Academies advisory: genes and toxic chemicals
3. Genomic technologies to identify toxic chemicals should be developed
4. Researchers study potential health benefits of natural chemicals in muscadine grape seeds
5. Study reveals huffing household chemicals connected to teen suicide
6. Marijuana-like brain chemicals work as antidepressant
7. Hazardous Advanced Micro Devices (A.M.D.) Clean Room Chemicals Caused Multiple Birth Defects, Lawsuit Alleges
8. How IAP antagonist chemicals kill tumors
9. Herons persist in Chicago wetlands despite exposure to banned chemicals
10. Hot liquids release potentially harmful chemicals in polycarbonate plastic bottles
11. Many Babies Exposed to Chemicals
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/13/2016)... ... , ... Valentine’s Day is nearly upon us, and most singles could probably ... flawless hair, and a sparkling personality are all well and good, but if somebody ... home with Rover. (Actually, man’s best friend might not even want to be near ...
(Date:2/13/2016)... ... February 13, 2016 , ... In its newly ... vein visualization technology should be used to ensure patient safety when placing an ... INS Standards mandate the use of vein visualization technology in patients with difficult ...
(Date:2/12/2016)... ... 12, 2016 , ... According to an article published February 4th ... significant portion of hernia repairs throughout the United States. Commenting on this article, Beverly ... that this trend has not only been expected, but it seems to be a ...
(Date:2/12/2016)... ... February 12, 2016 , ... CDRH Enforcement Trends: , Back to the Future , ... , As Winston Churchill said, “Those who don’t learn from history are doomed to ... expect when they come knocking this year. But that takes time. , Take a ...
(Date:2/12/2016)... ... February 12, 2016 , ... T.E.N., a ... closed for the ISE Southeast Awards 2016. Finalists and winners of the ISE® ... Southeast Executive Forum and Awards Gala on March 15, 2016 at the Westin ...
Breaking Medicine News(10 mins):
(Date:2/12/2016)... 12 2016  OMS Supply, a large provider of ... announced today the recent launching of their new company ... of features that enhance the user experience and enable ... --> --> Despite ... company that started in early 2016, they have already ...
(Date:2/11/2016)... Feb. 11, 2016 - ... in Personalized Medicine and Cancer Therapy. - European ... Diagnostic Testing Markets. - Key Diagnostic Testing Markets. ... Molecular Diagnostics in Genetic Testing. - Molecular Diagnostics ... - Over-the-Counter Diagnostic Products World Markets. - ...
(Date:2/11/2016)... -- Kindred Biosciences, Inc. (NASDAQ: KIN ), a biopharmaceutical ... pets, today announced the submission to FDA of the ... (NADA) for Zimeta™ (dipyrone injection, KIND-012).  Positive topline results ... the control of pyrexia (fever) in horses were recently ... --> The Chemistry, Manufacturing, and Controls technical ...
Breaking Medicine Technology: