Heavy agricultural reliance on synthetic chemical
fertilizers and pesticides is having serious impacts on
public health and the environment (Pimentel et al. 2005). For
example, more than 90% of US corn farmers rely on herbicides
for weed control (Pimentel et al. 1993), and one of the
most widely used of those herbicides, atrazine, is also one of
the most commonly found pesticides in streams and groundwater
(USGS 2001). The estimated environmental and health
care costs of pesticide use at recommended levels in the
United States run about $12 billion every year