Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study Finds Steroids May Persist Longer in the Environment Than Expected

27.09.2013
University of Iowa-led research shows some drugs can partially regenerate themselves

Assessing the risk posed to aquatic organisms by the discharge of certain steroids and pharmaceutical products into waterways is often based on a belief that as the compounds degrade, the ecological risks naturally decline.

But there's growing sentiment that once in the environment, some of these bioactive organic compounds may transform in a way that makes their presumed impact less certain.

A new study led by the University of Iowa and published online Thursday in the journal Science found this was the case with the anabolic steroid trenbolone acetate and two other drugs.

Once popular in the bodybuilding and weightlifting communities,trenbolone acetate is now banned for human use. However, it is federally approved for use by the beef industry to promote weight gain and increase feeding efficiency in cattle.

In lab tests followed by field experiments, the researchers found that trenbolone does not fully break down in water as believed, retaining enough of a chemical residue to regenerate itself in the environment under certain conditions, to an extent that the drugs' lives may be prolonged, even in trace amounts.

Researchers says the study is a first step toward better understanding the environmental role and impact of steroids and pharmaceutical products, all of which have been approved by the federal government for various uses and that have been shown to improve food availability, environmental sustainability and human health.

"We're finding a chemical that is broadly utilized, to behave in a way that is different from all our existing regulatory and risk-assessment paradigms," says David Cwiertny, assistant professor in engineering at the University of Iowa and a co-corresponding author on the paper."What our work hopefully will do is help us better understand and assess the environmental fate of emerging contaminant classes. There are a variety of bioactive pharmaceuticals and personal-care products that we know are present in trace amounts in our water supply. We should use what we're learning about trenbolone to more closely scrutinize the fate and better mitigate the impact of these products in the environment."

The team found similar results for dienogest, a hormone used in a birth-control pill called Natazia, and dienedone, a banned anabolic steroid that has been marketed as a body-building supplement.

Trenbolone acetate is implanted in the ears of more than 20 million cattle in the United States, according to studies cited by the researchers in their paper. The drug is metabolized and then excreted by livestock, and makes its way into waterways mainly through runoff.

The steroid has been considered safe due to its rapid degradation, with studies pointing to an environmental half-life of less than a day. But there has been concern that it and other synthetic drugs, when found in concentrated amounts, can be harmful to aquatic species and the environment generally. Studies have pointed to steroids and other drugs' effects on fish, through fewer eggs produced by females to skewing the sex of some species.

"We rarely see fish kills anymore, and we probably aren't discharging many carcinogens into surface waters anymore. But I don't believe this necessarily means that our water is safe for aquatic organisms," says Edward Kolodziej, associate professor in engineering at the University of Nevada-Reno and the other corresponding author on the Science paper. "It just might be harder to characterize the adverse effects associated with contaminant exposures these days."

Sunlight is one catalyst for breaking down compounds in the environment. But in this study, by simulating day and night in the lab, the research team found that the steroid's chemical compounds never fully disappeared in daylight. Moreover, during a simulated night, under typical surface water conditions, some of the compounds regenerated themselves, to as much as 60 percent of the metabolite's initial mass, when tracked over a 120-hour period.

"We knew something unique was going on," Cwiertny says. "In daylight, it essentially hides in another form, to evade analysis and detection, and then at nighttime it readily grows back."

More of the drug's mass was regenerated – up to 88 percent in one highly acidic state (pH 2) – when water temperature was higher and when it was more acidic or alkaline, the team found.

The researchers validated the lab results with two experiments in the field – one with water culled from the Iowa River in Iowa City, Iowa and the other from samples taken from a collection pond at a cattle rangeland and research operation run by the University of California.

Shen Qu, a post-doctoral researcher at the UI who studied under Cwiertny, is the first author on the paper. Contributing authors from the UI include Sarah Long, graduate research assistant in chemistry; James Gloer, chemistry professor; and Matthew Tarnoff, a senior in engineering. Jonas Baltrusaitis, who earned his doctorate at the UI and is now at the University of Twente, in the Netherlands, is a contributing author. Other contributing authors, all from Nevada-Reno, include Gerrad Jones, Peter Benchetler, Emily Cole and Kaitlin Kimbrough. Eric Patterson, now at Stony Brook University but who worked on the study while at Truman State University, also contributed to the paper.

The U.S. Department of Agriculture (grant numbers: 2010-65102-20425 and 2010-65102-20407), National Institutes of Health (grant numbers: S10-RR025500, UL 1RR024979 and P20 GM103440-11) and the National Science Foundation (grant numbers: CHE-074096, CHE-1039925 and CHE-1044356).

Richard Lewis | Newswise
Further information:
http://www.uiowa.edu

More articles from Ecology, The Environment and Conservation:

nachricht Dune ecosystem modelling
23.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht Understanding animal social networks can aid wildlife conservation
23.06.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>