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 Listening in: Acoustic monitoring devices detect illegal hunting and logging
14.12.2017 | Gesellschaft für Ökologie e.V.

nachricht How fires are changing the tundra’s face
12.12.2017 | Gesellschaft für Ökologie e.V.

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: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

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

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>