Determination of some selected heavy metals in catfish samples collected from some dams in Katsina state, Nigeria.

Abstract

This study was conducted to determine the concentrations of Cadmium, Cobalt, Copper, Nickel, Lead and Zinc in the Gill, Muscle and Tails of African catfish collected from Gwaigwaye, maska and Zobe dams in Katsina state, Nigeria across the dry and wet seasons. The   collected tissues of African catfish were digested and analyzed for the  toxic metals using microwave plasma atomic emission spectroscopy (MPAES). The levels of the metals obtained  were compared with acceptable limits of world health organization(WHO) and Standard organization of Nigeria(SON).The metal levels were found in the following ranges, 0.0132±0.01 to 0.057±0.02 mg/kg for Cd, 0.00±0.00 to 0.887±0.01 mg/kg for Co, 0.090±0.00 to 0.26±0.00 mg/kg for Cu, 0.00±0.00 to 0.138±0.01 mg/kg  for Ni, 0.00±0.00 to0.003±0.00 mg/kg for Pb and 0.133±0.04 to 0.855±0.01mg/kg for Zn for catfish gill in dry and wet seasons. Likewise, the concentration levels of the metals in catfish muscle in the following ranges were as follows 0.01±0.00 to 0.076±0.01 mg/kg for Cd, 0.00±0.00 to 0.048±0.01 mg/kg for Co, 0.066±0.04 to 0.108±0.03 mg/kg for Cu, 0.01±0.00 to 0.096±0.03 mg/kg for Ni, 0.00±0.00 to 0.01±0.00 mg/kg for Pb and 0.036±0.05 to 0.411±0.04 mg/kg for Zn . Similarly, 0.019±0.01 to 0.029±0.03 mg/kg for Cd, 0.00±0.00 to 0.091±0.01 mg/kg for Co, 0.079±0.01 to 0.133±0.03 mg/kg for Cu, 0.016±0.03 to 0.116±0.01 mg/kg for Ni, 0.00±0.00 to 0.023±0.03 mg/kg for Pb and 0.323±0.03 to1.08±0.01 mg/kg for Zn in catfish tail in both dry and wet seasons.  The levels of the metals were found to be below the safe limits set by both WHO and SON. African catfish from gwaigwaye, maska and zobe dams are therefore safe for human consumption. The results of statistical analysis and P values<0.05 indicated no significant   difference   between the tissues of African catfish analyzed across all the dams in both seasons.