Cadmium, Copper, Lead and Zinc Tissue Levels in Bonga Shadud(Ethmalosafimbriata) and Tilapia (Tilapia guineensis)udCaught from Imo River, Nigeria

摘要

An investigation of the muscle-liver tissue concentrations of heavy metalsud(Cd, Cu, Pb and Zn) in two commercially important fish species (EthmalosafimbriataBongaudshad and Til apia guineensis-Tilapia) caught from three stations within Irno River wasudcarried out in 2004. Heavy metal contents varied significantly (p>0.05) depending on theudfish species and on the type of tissues. The concentrations of the essential elementsud(Zn, Cu) were relatively higher in the muscle and liver tissues than the non-essential metalsud(Pb, Cd). The trends in tissue elemental concentrations in both species of fish wasudZn>Cu>Pb>Cd. Heavy metal levels in liver tissues of both fish species were comparativelyudhigher than levels obtained from muscle tissue. In general, T. guineensis showed higher levelsudof metal concentrations thanE. fimbriata. The concentrations of Cu, Cd, Pb and Zn in bothudfish species were within tolerance limits that are safe for human consumption.