By Mark Matheny
This article appeared in The Columbus Dispatch on March 2, 2010. It reminded me of some of the remarks in the book Ecoscience written by John Holdron in 1977 wherein he advocated putting sterilants in the water supply in order to control population.Herbicide turns male frogs female, study says
By David A. Farenhold
The Washington times
Washington- A new Study shows that male frogs exposed to the herbicide atrazine- commonly found in U.S. rivers and streams- can make a startling developmental U-turn, turning female so completely that they can mate with other males and lay viable eggs.
The study will focus new attention on concerns about atrazine, which is applied to an estimated 75 percent of American cornfields. Its manufacturer, the Swiss agricultural giant Syngenta, says the product is safe for wildlife, and for people who are exposed to small amounts in drinking water.
In recent years, however, some studies have seemed to show that atrazine can drive natural hormone systems haywire in fish, birds, rats, and frogs. In some cases, male animals exposed to the chemical developed female characteristics.
The study led by Tyrone Hayes, a professor at the University of California, was published in the proceedings of the National Academy of Sciences. It showed an even starker transformation: Among a group of male African clawed frogs raised in water tainted with atrazine, he said, a fraction grew up to look and act like females.
"Ten percent of the chromosomal males become completely, functionally female," Hayes said in a telephone interview. "They can lay eggs (and) they mate with other males."
The offspring of those unions were all male, he said, since both parents were genetically male. No female frogs were treated with atrazine in the study.
The other 90 percent of the exposed frogs retained some male features, Hays said, but often showed signs of "feminization," including lower testosterone levels and fertility. When pitted head -to- head against males that had not been exposed to atrazine, the atrazine-treated males frequently lost out in competion for female frogs.
Hayes said the reason for these changes could be that atrazine, when absorbed through the frog's skin, helps produce an enzyme that converts an unusual amount of testosterone into estrogen.
Those findings run counter to the U.S. Environmental Protection Agency's pronouncement in 2007 that atrazine does not cause problems in amphibian development. (Bold printed emphasis added)
Now think about the article in light of a quote taken from the book Ecoscience:
Adding a sterilant to drinking water or staple foods is a suggestion that seems to horrify people more than most proposals for involuntary fertility control. Indeed, this would pose some very difficult political, legal, and social questions, to say nothing of the technical problems. No such sterilant exists today, nor does one appear to be under development. To be acceptable, such a substance would have to meet some rather stiff requirements: it must be uniformly effective, despite widely varying doses received by individuals, and despite varying degrees of fertility and sensitivity among individuals; it must be free of dangerous or unpleasant side effects; and it must have no effect on members of the opposite sex, children, old people, pets, or livestock. Pg 787-788
In this statement Holdron says "No such sterilant exists today, nor does one appear to be under development."
I wonder.
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