The herbicide atrazine, heavily used in agriculture, is once again being implicated in the sexual mutation and decline of worldwide frog populations. The most recent study conducted by University of California Berkley professor Tyrone Hayes seems to point to this herbicide as the definitive cause for male frogs developing the physical characteristics of females.
The 40 young African Clawed frogs in the test were exposed to a water environment that contained 2.5 parts per billion (ppb) of atrazine for three years. Seventy five percent were chemically castrated by the exposure. Ten percent of them grew to be females, and were able to mate with males, but because they were genetically males, all of the offspring were males. In a population, these genetically male females can wipe out a population because they skew the sex ratio so badly.
Over 80 million pounds of this herbicide are applied annually in the United States to corn and sorghum crops to control weeds and increase yields. This intense use makes atrazine the most common pesticide contaminant of ground and surface water according to various studies.
The Environmental Protection Agency is reviewing its regulations on the use of the product. The European Union currently bans the use of atrazine. Several states are considering banning the product. Incidentally, the current standard set by the EPA for atrazine in drinking water is 3 parts per billion.
For more information on this topic, please visit http://www.medicalnewstoday.com/articles/180882.php, or http://berkeley.edu/news/media/releases/2010/03/01_frogs.shtml.
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