Concentrations of butyltin compounds (mono-, di-, and tri-butyltin) were determined in dolphin (Platanista gangetica), fish, invertebrates and sediment collected from the River Ganges, India, in order to understand the contamination levels, sources, and potential for biomagnification in freshwater food chains.

Large-scale episodal mortality among the freshwater fishes of certain
lakes of Bangalore City, Karnataka State, India occurred in June 1995.
We conducted an intensive study of the Sankey Lake which is situated in
Sadashiva Nagar of Bangalore city where fish mortality occurred on quite
a large scale during June - July 1995. These studies reveal that the fish-

Calculated loading rates of trace metals into the three environmental compartments demonstrate that human activities now have major impacts on the global and regional cycles of most of the trace elements. There is significant contamination of freshwater resources and an accelerating accumulation of toxic metals in the human food chain.