Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Chemicals remaining after wastewater treatment change the gender of fish

Male fish that used to be feminized after chemicals, such as the pharmaceutical ethinylestradiol, made it through the Boulder, Colo., Wastewater Treatment Plant and into Boulder Creek, are taking longer to become feminized after a plant upgrade to an activated sludge process, according to a new study. The results will be presented Sunday at The Endocrine Society's 92nd Annual Meeting in San Diego.

Although the levels of the chemicals that the fish swam in were very low even before the upgrade, the chemicals are endocrine disrupters. They mimic estrogen and may disrupt the endocrine (hormone) system of both animals and humans, said the study's principal investigator, David Norris, PhD, an integrative physiology professor at the University of Colorado at Boulder.

Norris' team reported in 2006 that native male fish in Boulder Creek decreased in numbers with respect to females and numerous intersex fish were found downstream of the wastewater treatment plant. After a technology upgrade to the wastewater treatment plant in 2008, the reproductive disruption in the fish was far less pronounced. However, Norris said the study results should still concern people.

"The fish are a wake-up call," Norris said. "Our bodies and those of the much more sensitive human fetus are being exposed everyday to a variety of chemicals that are capable of altering not only our development and physiology but that of future generations as well."

With other scientists, Norris studied samples of the wastewater effluent, the plant-treated water that enters the stream and becomes another city's drinking water. Grants from the U.S. Environmental Protection Agency (EPA) and the city of Boulder supported this research.

They found other endocrine disrupters, including synthetic and natural reproductive steroids. They believe the chemicals come from natural female hormones and birth control pills excreted via urine and from detergents, cosmetics and other consumer products flushed down toilets and drains. The amount of estrogens in the sampled effluent was enough to explain the effects on the fish "downstream" from the treatment plant—in the river below the plant, according to Norris. The researchers saw no signs of reproductive disruption in fish upstream.

Also, the investigators exposed adult male fathead minnows to wastewater effluent they diluted with water taken from upstream of the plant. After seven days' exposure to this water, the fish had suppressed male sex characteristics and greatly elevated levels of the protein vitellogenin. Female fish make vitellogenin under the influence of estrogens, and male fish produce very little of it, so elevated levels in males indicate estrogen exposure, Norris explained.

After the technology upgrade to the wastewater treatment plant in 2008, the effluent was considerably less estrogenic to the fish. After the treatment plant's upgrade, the minnows exhibited less intense loss of male sex characteristics, an initial analysis found. "It took 28 days to get a significant elevation in vitellogenin and then only in 100 percent effluent," Norris said. "However, these improvements seen in wildlife will not substantially lessen the risk to human health because drinking water is not the major source of estrogenic chemicals for people."

Aaron Lohr | EurekAlert!
Further information:

More articles from Studies and Analyses:

nachricht Diagnoses: When Are Several Opinions Better Than One?
19.07.2016 | Max-Planck-Institut für Bildungsforschung

nachricht High in calories and low in nutrients when adolescents share pictures of food online
07.04.2016 | University of Gothenburg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

'Neighbor maps' reveal the genome's 3-D shape

27.10.2016 | Life Sciences

Gene therapy shows promise for treating Niemann-Pick disease type C1

27.10.2016 | Life Sciences

Solid progress in carbon capture

27.10.2016 | Power and Electrical Engineering

More VideoLinks >>>