Abstract



Water pollution by heavy metals is an emerging problem in both developed and undeveloped countries. This research was carried out to determine the concentration of Ni, As, Cu, Fe, Pb and Cd in periwinkle (T. fuscatus) tissues and shell from Okoro Ete River, Eastern Obolo, Akwa Ibom State, using UNICAM 629 Atomic Absorption Spectrometer. The mean concentrations of each heavy metals: Ni (0.72 ± 0.20 mg/kg); Cu (9.23 ± 5.60 mg/kg); Fe (56.98 ± 32.03 mg/kg); Pb (17.64 ± 4.00mg/kg); Cd (22.46 ± 5.50 mg/kg) in Tympanotonus fuscatus tissues were higher than the concentration of metals: Ni (BDL); Cu (0.41 ± 0.23 mg/kg); Fe (33.17 ± 12.80 mg/kg); Pb (1.49 ± 0.20 mg/kg); and Cd (2.21 ± 1.00 mg/kg) in shell samples and also higher than the WHO and FAO permissible standards of 0.5 mg/kg (Ni); 0.2 mg/kg (Cu); 5.0 mg/kg (Fe); 5.0 mg/kg (Pb); and 2.0 mg/kg (Cd) indicating higher levels of accumulation of these metallic contaminants by the test organisms implying that these organism may pose high risk upon human consumption due to high pollution of the study area by heavy metals contaminating from both point source and non point source. The result of this study revealed a very high concentration of Lead both in the tissues and shell of T. fuscatus. This indicates that T, fuscatus from Okoro Ete River, Eastern Obolo, Akwa Ibom State is unfit for human consumption.