ABSTRACT
Pesticides have been used worldwide for pest control in crops, allowing the increase in crop productivity and improved product quality. Their use has been considered a revolution in agriculture, but, due to their high toxicity, many of them were included in the Stockholm Convention (1972) and declared as persistent organic pollutants (POPs). From 1970s, many of these pesticides have been forbidden in most countries; however, in 1992, approximately 2.5 million tons of pesticides were used around the world (Pimmentel et al. 1992). Although pesticide use has been controlled gradually, there may be more than 20,000 tons of obsolete pesticides in developing countries, and stocks are growing because a lot of these countries do not have environmental policies in this regard (FAO 1997).
