Accumulation Pattern of Pesticides in Tropical Fresh Waters

High-performance liquid chromatography has been used to study the persistence of commonly used organophosphorus and carbamate pesticides-carbaryl, carbendazim, carbofuran, dimethoate, malathion and methyl parathion in river water in the presence of bottom sediment in laboratory aquaria. The fate of pesticides in water and sediment in pre- and post-monsoon water from three sources has been compared. It has been established that rapid degradation occurs once the pesticide leaches into sediment from water. Degradation was at a much faster rate in post-monsoon water and sediment. It was found that pH and organic matter content affect rate of decay.