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

>>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 
>>Call in with your comments and questions at 1-800-989-8255, and 
>>share your opinions online in our Listeners' Lounge (registration 
>>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)
>>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 
>>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.

Richard A. Worth
Oregon Department of Agriculture
Plant Division
rworth at oda.state.or.us
(503) 986-6461
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