The herbicide also contaminates drinking water supplies in many communities in the Midwest, leading some environmental groups to voice concern about its effect on children, infants and the fetus. France, Germany, Italy, Sweden and Norway are among countries that have banned the use of atrazine.
"This is very important and elegant work," said Theo Colborn, PhD, a senior scientist at the World Wildlife Fund and an internationally recognized expert on endocrine disrupting chemicals. "Tyrone's work demonstrates the need to do research on the safety of chemicals in the field where the animals live and at the levels to which they are exposed. The changes he found in the gonads were not discovered with the traditional high-dose atrazine experiments used in the past. In addition, microscopic examination of the internal organs of the frogs is required to detect the hidden effects from low-dose exposure."
To date, atrazine's effects on mammals and amphibians have been tested only at large doses, not at doses commonly found in the environment.
In their journal article, Hayes and his colleagues write, "The effective doses in the current study ... demonstrate the sensitivity of amphibians relative to other taxa, validate the use of amphibians as sensitive environmental monitors/sentinels, and raise real concern for amphibians in the wild."
Hayes doubts that atrazine has such severe effects on humans, because the herbicide does not accumulate in tissue and humans don't spend their lives in water like frogs do. Nevertheless, the effects of atrazine
Contact: Robert Sanders
University of California - Berkeley