ATRAZINE DEBATE INTENSIFIES: EPA zeroes in on hormone effects, grapples with CONTRADICTORY DATA

IT’S BEEN ONE YEAR since the Environmental Protection Agency decided to reevaluate the toxicity of atrazine, one of the most commonly used herbicides in the U.S. The agency’s review was expected to be nearly complete by now, but a plethora of new and contradictory studies on the health effects of atrazine have bogged down the process. EPA assessed the risks of atrazine in 2006 and determined that the 50-year-old weed-killing chemical is safe for use on corn, sorghum, and other crops when applied as directed. Last year, however, the agency decided to take another look at the herbicide because of a handful of studies showing an association between atrazine exposure and birth defects, premature births, and low birth weight in humans (C&EN, Oct. 12, 2009, page 36). The agency now acknowledges that the quality of those human epidemiology studies is insufficient for use in a quantitative risk assessment of atrazine. Nonetheless, EPA plans to ...