Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Common Weed Killer Disrupts Frog’s Sexual Development

16.04.2002


Exposure to less than one part per billion of the most commonly used herbicide in the U.S. can feminize male frogs, according to a new study. The findings, published today in the Proceedings of the National Academy of Sciences, suggest that concentrations of chemicals considered safe for humans can have insidious effects on amphibians and could be contributing to the global decline in their populations.


Image: Courtesy Tyrone Hayes/UC Berkeley



Tyrone B. Hayes of the University of California, Berkeley, and colleagues studied the effects of atrazine, a widely used weed killer, on the growth of the African clawed frog, Xenopus laevis (see image). The researchers exposed larvae and tadpoles to varying levels of the chemical and found that concentrations of atrazine as low as 0.1 part per billion affected the sexual development of the animals. Some 16 percent of the animals subjected to such concentrations, the investigators determined, either had more than the normal number of sexual organs or had both male and female organs. None of the control animals experienced such abnormalities. The team further found that 80 percent of adult males that had been exposed to the chemical had smaller-than-average vocal organs and many exhibited testosterone levels below those found in normal females. "If such effects occur in the wild," the authors conclude, "exposed animals would suffer impaired reproductive function."

The frogs probably experienced these extreme consequences because they spent so much time immersed in water contaminated with the chemical. It is unlikely that atrazine has such severe effects on humans, Hayes says, because people are not exposed to it for long periods of time. But because the concentrations that affected the animals were so small--30 times lower than the current allowable limit in drinking water--the findings support the use of amphibians as environmental sentinels. Says Theo Colborn of the World Wildlife Fund: the work "demonstrates the need to do research on the safety of chemicals in the field where the animals live and at the levels to which they are exposed."

Sarah Graham | Scientific American

More articles from Ecology, The Environment and Conservation:

nachricht Scientists on the road to discovering impact of urban road dust
18.01.2018 | University of Alberta

nachricht Gran Chaco: Biodiversity at High Risk
17.01.2018 | Humboldt-Universität zu Berlin

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: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>