Acute lethal toxicity of the organophosphorus pesticide chlorpyrifos to different species and strains of Artemia.

Presently, organophosphorus pesticides (OPs) have largely replaced organochlorine compounds in the agricultural activities. Total turnover of OPs has increased around the world. Their residues have been detected in ground and drinking waters (Barceló, 1993), natural surface waters (Hernández et al., 1996), marine organisms (Barceló et al., 1990) and food products (Gunderson, 1995; Dejonkeheer et al., 1996). Chlorpyrifos[O,O-diethylO-(3,5,6-trichloro-2-pyridil) phosphorothiate, CAS RN 2921-88-2, Dursban, Lorsban, Spannit] is a widely used organophosphorus pesticide in the countries of the European Union (>50000 kg per year) (UNEP 1991). It is classified as probable or transient leacher (Barceló, 1993) according to its half-life time in soil and its adsorption coefficient (Gustafson, 1989).