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Weed killing toxin makes mothers out of male frogs

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Green Frog

Atrazine, a controversial herbicide ubiquitous in Canadian cornfields has been found to chemically castrate male frogs, turning them into egg laying females.

The Globe and Mail reported yesterday that when scientists at the University of California Berkley exposed male African clawed frogs to minute amounts of the toxin, just 2.5 parts per billion,the mutation occurred.

Of the 40 exposed male frogs, four were turned into females, four were normal males, and the rest were emasculated, with decreased testosterone levels, feminized larynxes, and decreased sperm production.

There has been no word on it’s affect on humans, both the weed killer’s Swiss Manufacturer, Syngenta AG, and Health Canada refuse to concede to any dubious effects. But Health Canada’s opinion doesn’t inspire the utmost confidence, a 2004 evaluation of the toxin found that Atrazine “[does] not entail an unacceptable risk to human health.”

Which of course demands the follow up: What would constitute an acceptable risk to human health?

The European Union banned the use of Atrazine in 2004 because of it’s persistence in groundwater contamination, North America has similar concentrations of contamination, but its use is still fairly universal.

It is strongly persistent and is one of the most significant water pollutants in rain, surface, marine, and ground water. Its persistence (it has a half-life of 125 days in sandy soils) and mobility in some types of soils because it is not easily absorbed by soil particles, means it often causes contamination of surface and ground waters. In the US for example, it has been found in the groundwater of all 36 river basins studied by the US Geological Survey and the USGS estimates that persistence in deep lakes may exceed 10 years.

Health Canada Actually allows up to 5 ppb in drinking water, double the dose used in the trials at Berkley. This means that amphibians actually could be exposed to greater levels of Atrazine in their natural habitat. The find could lead to answers over declining frog populations around the world.

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