endless studies to keep atrazine polluting

[jcummins <jcummins@UWO.CA>]

The article below deals with the maneuvering over  atrazine "to ban or 
not to ban, that is the question". Efforts are being made to carry on 
endless studies to keep atrazine polluting the planet. Atrazine tolerant 
canola , claimed to have been   selected from volunteers (TT canola ) is 
being grown in Australia in spite of its yield deficiency. TT soy and 
other crops may push the globe to the edge of ecological doom.
Nature 420, 256 (2002); doi:10.1038/420256a

Doubts linger over America's top herbicide REX DALTON
[SALT LAKE CITY] Rising concerns about the environmental impact of the 
most widely used herbicide in the United States have led researchers to 
call for more time to study its effects before approval for the agent's 
use is renewed.

Researchers have until next February to submit their findings on the 
herbicide atrazine to the Environmental Protection Agency (EPA). The 
agency plans to complete its review of the chemical during 2003.

But at the annual meeting of the Society of Environmental Toxicology and 
Chemistry (SETAC) in Salt Lake City, Utah, this week, some scientists 
said that the necessary studies cannot be finished in time for the EPA's 
deadline.

Researchers in the field want to conduct a detailed study of what 
concentrations of atrazine cause environmental damage by disrupting the 
sexual development of amphibians, says Timothy Gross, an ecotoxicologist 
with the US Geological Survey in Gainesville, Florida.


Tyrone Hayes suggests that reasonably low levels of atrazine can 
adversely affect frogs' development.

Earlier this year, two studies indicated that atrazine at levels as low 
as 0.1 parts per billion (p.p.b.) in water disrupted the sexual 
development of male frogs (T. Hayes et al. Proc. Natl. Acad. Sci. USA 
99, 5476–5480; 2002 and T. Hayes et al. Nature 419, 895–896; 2002).

But other scientists, including Gross, dispute this, and have released 
unpublished results showing that much higher water concentrations of 
about 25 p.p.b. are needed to affect the frogs' sexual development. 
Government studies show that atrazine can be found at levels as high as 
50 p.p.b. in US waters, and at even higher concentrations of several 
parts per million in agricultural run-off.

"The water is very muddy right now," says Gross, who also serves on a 
panel studying atrazine for Syngenta, the herbicide's Swiss-based 
manufacturer. Syngenta wants the EPA to re-register atrazine for use in 
the United States. It has been banned in some European countries.

Gross' comments came after a spirited session at the SETAC meeting where 
academic and industry-backed scientists presented their findings on the 
impact of atrazine on wild and laboratory amphibians.

Tyrone Hayes — an evolutionary endocrinologist at the University of 
California, Berkeley, who is the lead author of the studies in Nature 
and the Proceedings of the National Academy of Sciences — was added at 
the last minute to the SETAC session, which already included prominent 
university scientists, such as James Carr of Texas Tech University in 
Lubbock, whose studies of atrazine are funded by Syngenta.

Once February's deadline is reached, the EPA will set up a scientific 
advisory panel to advise it on re-registering atrazine. A decision is 
expected next October.

But both Hayes and Gross say that a new study is needed to settle the 
debate, and that the February deadline won't allow this to happen. "We 
need a tie-breaker study," says Gross.

Thomas Steeger, an EPA biologist working on atrazine re-registration, 
says that the agency may be reluctant to extend the study deadline. But 
he adds that he wouldn't be surprised if the scientific advisory panel 
called for more study before issuing a recommendation on how the
herbicide should be regulated.

.