Weed Killer turns boy frogs into girls

March 2, 2010

Atrazine, a commonly used weed killer in California, turns male frogs into reproducing female frogs, according to a study performed by University of California at Berkeley researchers. [Reuters]

First, atrazine-exposed male frogs develop female features – termed hermaphroditism. Then a small percentage became female frogs through chemical castration.

“Ten percent of the exposed genetic males developed into functional females that copulated with unexposed males and produced viable eggs,” the researchers wrote.

The study included 40 African clawed frogs that were kept in water contaminated with 2.5 ppb (parts per billion) of atrazine. The EPA’s current drinking water standard is 3 ppb.

The European Union banned atrazine in 2004. In the United States, the chemical is the most common pesticide found in ground and surface water, the researchers said.