Abstract:
Concentration of zinc, copper and lead were investigated in the gill, gonads, skin and muscle tissues of six commercially edible fishes from upper stretch of the Ganga River at West Bengal, India. The study area receives a wide variety of wastes generated by municipalities and the industries like paints and pigments, metal processing industries, thermal power plants, electro-processing industries etc. situated on the both side of the river Ganga. Simultaneous analysis of the metals was also carried out in the sediment and aquatic phases to monitor the degree of contamination. Although in the study area, the availability of heavy metals is still below alarming level (the acceptable limit for human consumption of the heavy metals are copper 10 μg g-1, zinc 150 μg g-1 and lead 1.5 μg g-1) but if the present trend continues, the level might get elevated and the consumption of the contaminated fishes might pose severe health hazards to human beings in times to come. The results of this study indicated that the six commercially edible fishes through food, water and sediment leading thereby to bioaccumulation took the metals present in the river ecosystem. The degree of bioaccumulation was directly proportional to the concentration of heavy metals in water phase and found to follow the order pre-monsoon