Histotoxicity Associated with Some Heavy Metals in Tilapia (Oreochromis niloticus) from Eleyele River, South-Western Nigeria

  • Kenneth C. Onyegbula
  • Gideon T. Oluwaloye
  • Ayodele A. Okesola


We determined the concentration of Iron, Zinc, Copper, Lead and Cobalt in water, gills, liver, intestine and muscle of Tilapia (Oreochromis niloticus) obtained from Eleyele River, South-western Nigeria with the objective of assessing risk to fish and human health by estimating the pattern of metal-bioaccumulation, hazard quotient and histopathology. The result reveals that Iron was the most abundant in both water and fish tissues. Mean concentration of Iron in water was above all permissible limits used for comparison. The liver exhibited a higher capacity for metal bioaccumulation. Histological deformations observed in the tissues and the high hazard quotient of Lead indicated risk to fish and human health. These findings therefore call for urgent interventional actions by government and non-governmental organizations interested in issues of safe water to channel all efforts at identifying the source(s) of these pollutants in order to stem their release into the reservoir to avoid possible future Lead poisoning. Keywords: Bioaccumulation, gills, liver, intestine, muscle