ABSTRACT
Parathion is released to the environment primarily during agricultural application as a broad-spectrum insecticide. Parathion will bind tightly to soil and decay by biological and chemical hydrolysis in several weeks forming p-nitrophenol, diethylthiophosphoric acid, and paraoxon. Degradation in flooded soil is much faster and aminoparathion is formed under the low oxygen conditions. Parathion strongly adsorbs to soil and degrades by both biological and soil-catalyzed hydrolysis. Photolysis may occur at the surface. The photolysis of parathion was studied in water, aqueous methanol, or aqueous propanol in presence of other compounds, under aerated, or degassed conditions. Many different processes contribute to the degradation of parathion in the water and which of these processes contribute the most will depend upon the particular circumstances. Parathion is destroyed during composting agricultural wastes. Humans are exposed to parathion primarily during field application and formulating the insecticide.
