摘要：An investigation of the muscle-liver tissue concentrations of heavy metals (Cd, Cu, Pb and Zn) in two commercially important fish species ( Ethmalosa fimbriata -Bonga shad and Tilapia guineensis -Tilapia) caught from three stations within Imo River was carried out in 2004. Heavy metal contents varied significantly (p>0.05) depending on the fish species and on the type of tissues. The concentrations of the essential elements (Zn, Cu) were relatively higher in the muscle and liver tissues than the non-essential metals (Pb, Cd). The trends in tissue elemental concentrations in both species of fish was Zn>Cu>Pb>Cd. Heavy metal levels in liver tissues of both fish species were comparatively higher than levels obtained from muscle tissue. In general, T. guineensis showed higher levels of metal concentrations than E. fimbriata. The concentrations of Cu, Cd, Pb and Zn in both fish species were within tolerance limits that are safe for human consumption.
