Contamination of metals in different tissues of rohu (Labeo rohita, Cyprinidae) collected from the Indian River Ganga.

In the present paper, accumulation of zinc (Zn), iron (Fe), copper (Cu), chromium (Cr), nickel (Ni), manganese (Mn) and lead (Pb) was determined in different tissues (skin, muscles, liver, gills, kidney and brain) of rohu (Labeo rohita) collected from the River Ganga in Varanasi, India. Concentrations of Cu (except gills), Fe and Cr (except brain for Cr) in most of the tissues were above the permissible safe limits for human consumption suggested by the Food and Agricultural Organization (FAO 1983). Concentrations of all metals were higher in River Ganga fish than those from the University fish farm. With the exception of Zn in skin, muscle and brain tissue, the studied metals were bioaccumulated in all tissues. The total metal accumulation or metal pollution index was highest in liver (20.8 ± 0.50) followed by kidney (16.8 ± 0.44), gills (15.2 ± 0.15), muscles (12.1 ± 0.08), skin (10.5 ± 0.53) and brain (7.0 ± 0.02).