Research Article
NSOFOR, Charity & IKPEZE, Obi
Abstract
Spatial and seasonal concentrations of heavy metals Zinc (Zn), Iron (Fe), Copper (Cu), and Lead (Pb) in water columns and the African Catfish Clarias gariepinus of River Niger at Onitsha, Nigeria were determined using Atomic Absorption Spectrophotometer (AAS). Mean concentrations of the analyzed metals were significantly higher in catfish than water columns (P<0.05). Bioaccumulation of heavy metals in catfish indicated that River Niger was experiencing impairment. Results also showed that mean concentrations of Zn (3.9860.617) and Cu (0.8760.382) in Catfish were within WHO/UNEP/FEPA permissible limits in aquatic foods but Fe (5.2320.704) and Pb (0.2280.266) far exceeded their limits. Since prolonged consumption of heavy metal-contaminated Clarias gariepinus of River Niger may pose serious human health risks, it is necessary to make a comprehensive assessment of the hazards posed by other heavy metals in many fish species found in different Nigerian water bodies.