Overview

Atrazine is the most widely used herbicide in the United States and in the world (excluding the European Union). Its breakdown product, deethylatrazine, is one of the most commonly found groundwater contaminants in the United States (Goolsby, et al, 1993; Detroy, et al, 1988; Hallberg, 1989). The prevalence of atrazine in drinking water, coupled with a stream of sometimes conflicting reports on atrazine's environmental and human health effects, has generated a great deal of controversy around its safety. A wave of new research on atrazine's effects on wildlife lead environmentalists to sue the US EPA for failing to re-examine surface water contamination limits (New York Times, Duhigg, 2009). In 2004 the European Union, where atrazine was also a major surface water contaminant, removed atrazine from its list of approved agricultural chemicals. As a result, atrazine has been replaced in the EU by the related herbicide terbuthylazine, which is less likely to accumulate in drinking water.

In 2004, the same year that the EU passed its tighter drinking water limits for triazine herbicides, the EPA ruled atrazine safe when used in accordance with modified application guidelines. In 2007, the EPA undertook a joint monitoring program with Syngenta, atrazine's manufacturer, to examine seasonal spikes in atrazine concentrations in the drinking water of farming communities. While the monitoring study found no drinking water supply that exceeded permissible 24-hour concentrations, the program fed environmental and human health outcry when it was revealed that study communities were not informed of the atrazine spikes or counseled on reducing their exposure to the chemical. In 2010, the EPA will complete a another reappraisal of atrazine, bolstered in part by the National Cancer Institute's Agricultural Health Study.

Article Contents

History and Uses

Effects on Human Health

Effects on Wildlife

Atrazine Regulation in Europe and the United States

2009-2010 US Policy Initiatives

References