Organochlorine pesticide residues in sediments of a tropical mangrove estuary, India: implications for monitoring.
The paper examines the concentrations of isomers of hexachlorocyclohexane (HCHs), dichlorodiphenyl trichloroethane and its metabolites (DDTs), alpha-endosulfan and endosulfan sulfate in surface sediment samples collected from the mouth of Hugli estuary in the vicinity of Sundarban mangrove environment, eastern part of India. An overall pattern of accumulation of these pesticides was in the order of: SigmaHCH>endosulfan sulfate>SigmaDDT>alpha-endosulfan. The concentration of these compounds was quite low. An elevated level of SigmaHCH, SigmaDDT and endosulfan sulfate were marked during premonsoon months, a period characterized by high salinity and pH values. Among the isomers and metabolites of HCH and DDT, beta-HCH, pp'-DDT and pp'-DDE were found to be dominant. The sources of contamination are closely related to human activities, such as domestic and industrial discharges, agricultural chemical applications and soil erosion due to deforestation. The study is compared to other estuarine environment in India and abroad. The present data will serve as a baseline against which future anthropogenic effects may be assessed.
Department of Metallurgical Engineering, Jadavpur University, 700032 Calcutta, India. badalbhattacharya@hotmail.com
Badal
B
Bhattacharya
Santosh Kumar
SK
Sarkar
Nilanjana
N
Mukherjee
D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D006843:Hydrocarbons, Chlorinated; D007194:India; D007306:Insecticides / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis*; D012016:Reference Values; D014329:Tropical Climate
D006843:Hydrocarbons, Chlorinated; D007306:Insecticides; D010573:Pesticide Residues