Fwd: Atrazine- Science Friday NPR, Talk of the Nation
Richard Worth
rworth at oda.state.or.us
Fri Apr 19 10:48:45 EDT 2002
Atrizine discussion on NPR today
>>
>>http://www.npr.org/programs/totn/
>>
>>Science Friday > Archives > 2002 > April > April 19, 2002:
>>Hour Two: Atrazine & Frogs / Forensic Scientist Henry Lee
>>
>>Lately, forensic science -- the application of science to legal
>>proceedings -- has become cool. Popular dramas such as 'CSI,' as
>>well as countless hours of documentary television, have made the
>>public more aware of the tools and techniques investigators use in
>>their hunt for clues at crime scenes. In this hour of Science
>>Friday, we'll talk with renowned forensic scientist Henry Lee.
>>
>>Lee has been a consultant for over 300 police and law enforcement
>>agencies, and an expert witness in many high profile cases for both
>>the prosecution and the defense. He's been involved with cases
>>including the O.J. Simpson murder trial, the Jon Benet Ramsey
>>investigation, and war crimes cases in Bosnia. We'll hear about his
>>life, work, and the science behind cracking cases.
>>
>>Plus, we'll find out about new research published this week
>>suggesting a link between the common weed killer atrazine and
>>strange sexual characteristics in frogs. Atrazine is an herbicide,
>>used mainly for the control of broad-leafed and grassy weeds. It's
>>used heavily in agricultural areas, particularly for weed control
>>in corn fields. Though its use is restricted to professional
>>applicators, atrazine ranks as one of the most widely used
>>pesticides in the country.
>>
>>The EPA has defined a 'safe level' of atrazine in drinking water of
>>to be 3 parts per billion. In research published this week in the
>>Proceedings of the National Academy of Sciences, however,
>>researchers report finding altered sexual characteristics in frogs
>>exposed to as little as 0.1 ppb of atrazine. We'll find out more.
>>
>>At right: Abnormal gonads in a male Xenopus frog, the result of
>>exposure to the herbicide atrazine. The frog has become a
>>hermaphrodite -- that is, it has both male (testes) and female
>>(ovaries) sex organs. Credit: Tyrone Hayes/UC Berkeley, courtesy
>>PNAS
>>
>>Call in with your comments and questions at 1-800-989-8255, and
>>share your opinions online in our Listeners' Lounge (registration
>>required).
>>
>>Guests:
>>Tyrone Hayes
>>Developmental Endocrinologist
>>Laboratory for Integrative Studies in Amphibian Biology
>>Museum of Vertebrate Zoology
>>Associate Professor, Integrative Biology
>>Department of Integrative Biology
>>University of California, Berkeley
>>Berkeley, California
>>
>>Henry Lee
>>Chief Emeritus, Scientific Services and Former Commissioner of
>>Public Safety, State of Connecticut
>>Chief Criminalist, State of Connecticut 1979-2000
>>Author with Thomas O'Neil, "Cracking Cases: The Science of Solving
>>Crimes" (Prometheus, 2002)
>>
>>Ecology
>>Hermaphroditic, demasculinized frogs after exposure to the
>>herbicide atrazine at low ecologically relevant doses
>>Tyrone B. Hayes*, Atif Collins, Melissa Lee, Magdelena Mendoza,
>>Nigel Noriega, A. Ali Stuart, and Aaron Vonk
>>
>>Laboratory for Integrative Studies in Amphibian Biology, Group in
>>Endocrinology, Museum of Vertebrate Zoology, Department of
>>Integrative Biology, University of California, Berkeley, CA
>>94720-3140
>>
>>Communicated by David B. Wake, University of California, Berkeley,
>>CA, March 1, 2002 (received for review December 20, 2001)
>>
>>Atrazine is the most commonly used herbicide in the U.S. and
>>probably the world. It can be present at several parts per million
>>in agricultural runoff and can reach 40 parts per billion (ppb) in
>>precipitation. We examined the effects of atrazine on sexual
>>development in African clawed frogs (Xenopus laevis). Larvae were
>>exposed to atrazine (0.01-200 ppb) by immersion throughout larval
>>development, and we examined gonadal histology and laryngeal size
>>at metamorphosis. Atrazine (0.1 ppb) induced hermaphroditism and
>>demasculinized the larynges of exposed males (1.0 ppb). In
>>addition, we examined plasma testosterone levels in sexually mature
>>males. Male X. laevis suffered a 10-fold decrease in testosterone
>>levels when exposed to 25 ppb atrazine. We hypothesize that
>>atrazine induces aromatase and promotes the conversion of
>>testosterone to estrogen. This disruption in steroidogenesis likely
>>explains the demasculinization of the male larynx and the
>>production of hermaphrodites. The effective levels reported in the
>>current study are realistic exposures that suggest that other
>>amphibian species exposed to atrazine in the wild could be at risk
>>of impaired sexual development. This widespread compound and other
>>environmental endocrine disruptors may be a factor in global
>>amphibian declines.
>>------------------------------------------------------------------------
>>* To whom reprint requests should be addressed. E-mail:
>>tyrone at socrates.berkeley.edu.
>>www.pnas.org/cgi/doi/10.1073/pnas.082121499
Richard A. Worth
Oregon Department of Agriculture
Plant Division
rworth at oda.state.or.us
(503) 986-6461
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