Accumulation of copper, zinc and cadmium in liver, gill and muscle tissues of Oreochromis niloticus exposed to the metals singly and in mixture

Accumulation of copper (5 ppm), zinc (5 ppm), cadmium (1 ppm) in gill, liver and muscle tissues of Oreochromis niloticus were investigated after exposure to these metals singly and in mixture over 24, 48 and 96 hour periods. Tissue levels of the metals were determined using Atomic Absorption Spectrophotometric techniques.Liver, gill and muscle accumulation of all metals increased with increasing exposure periods at single and in mixture exposure to metals. Highest cadmium and zinc accumulations were observed in gill, liver and muscle tissues respectively whereas the highest copper accumulation was in liver, gill and muscle tissues.The highest cadmium accumulation was observed in gill, the highest copper accumulation copper in liver and the highest zinc accumulation was in gill tissues when exposed to copper-zinc-cadmium mixture.Effects of the metal mixture increased copper levels in liver while increasing zinc level in gill and muscle tissues at the tested concentrations.