Heavy metal distribution in Water, Sediment and some Benthic Organisms in Nwaniba River of Akwaibom State

This study assesses the distribution of heavy metals in water, sediment, and some benthic organisms in Nwaniba River, Akwa Ibom state. A total of 7 heavy metals (Fe, Cu, Ni, Pb, Zn, Cr and Mn) were determined using the Inductively Coupled Plasma Optical Emission Spectroscopic (ICP-OES) technique. The results showed mean concentration in water as: Cr(0.0061 mg/l), Cu(0.0437 mg/l), Mn(0.1124 mg/l), Ni (0.0351 mg/l) and Fe(3.1196 mg/l). The mean concentration of heavy metals in sediment, crab, periwinkle flesh and periwinkle shell ranged between 2.4479 - 101.8957 mg/kg for Cr, Cu (51. 8232 - 667.6241 mg/kg), Pb (5.5976 - 62.4141 mg/kg), Mn (522.0806 - 2976.9326 mg/kg), Ni (5.4470 - 49.3766 mg/kg), Zn (119.7862 - 1111.1128 mg/kg) and Fe (1495.6705 - 76838.1016 mg/kg). Iron had maximum concentrations in all the analyzed samples. The concentration of most of the heavy metals detected were extremely high and above maximum permissible limits set by WHO and FAO/WHO. Transfer factor (TF) values were greater than 1 indicating significant accumulation. The crab and periwinkles bio-accumulated Cu and Zn in their tissues. Constant monitoring of the anthropogenic activities and remediation of the Nwaniba River are urgently suggested.