Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Common Weed Killer Disrupts Frog’s Sexual Development


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 Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

nachricht Malaysia's unique freshwater mussels in danger
27.09.2016 | The University of Nottingham Malaysia Campus

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: 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...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

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

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>