Pesticide concentration in water and sediment of River Ganga at selected sites in middle Ganga plain

This study reports the concentration levels and distribution pattern of the persistent pesticides residues in water and bed sediments of the Ganga river at Bhagalpur stretch collected seasonally over a period of 2 years. The water and bed sediment were collected from three different sites (upstream, midstream and down stream) and analyzed for their pesticide profile. The study has shown the presence of both organochlorine and organophosphorous pesticides in the water and sediment of River Ganga at Bhagalpur. We used Liquid-liquid extraction followed by GC-ECD for the determination of these compounds. Among the various pesticides analyzed, high concentration of Methyl parathion, Endosulfan and DDT were observed both in water and sediment samples of the river. The concentration of DDT in sediment was quite high which might be due to slow degradation of DDT in soil i.e. 75 – 100% in 4–30 years. The present study was first attempt to identify and quantify some selected pesticides in water and sediment of the river Ganga at Bhagalpur, and may be important as the Bhagalpur city gets its water supply from the river for drinking purposes.