You are referring to the 2002 Hayes study. There was another study done in 2010 by Hayes that showed "atrazine rendered 75% of male frogs sterile and turned one in 10 into females.... Atrazine-exposed males suffered from depressed testosterone, decreased breeding gland size, demasculinized/feminized laryngeal development, suppressed mating behavior, reduced spermatogenesis, and decreased fertility."