Heavy Metal Pollution Of Fish Of Qua-Iboe River Estuary: Possible Implications For Neurotoxicity

The Qua-Iboe River rises from Umuahia in Abia State. It traverses about 150 km and empties into the Atlantic Ocean via Eket (Ibeno LGA) Akwa Ibom State, Nigeria. The Social, economic and cultural lives of the people are significantly linked to the river. Its estuary situates close to Exxon-Mobile crude oil effluent processing and treatment facility. The heavy metal pollution status of the estuary was investigated in the Qua-Iboe Terminal (QIT) community on the bank of the estuary, using the method of Franson (1975). Based on WHO safety reference standards, the results showed that the water was polluted with respect to all the metals tested except Mn and Zn. The mean (X) (n=10) was Ni = 0.21± 0.01, Cr = 0.53 ± 0.01, Cd = 0.03 ± 0.01, Mn = 0.14 ± 0.09 and Pb = 0.3 ± 0.1 mg/L respectively. The fish bioaccummulated some of the metals: Mean (X) (n=7) for Ni = 1.9 ± 0.1,Cr = ND, Cd = 0.38 ± 0.06, Mn = 12.85 ± 0.66 and Pb = 25.58 ± 1.2 mg/g respectively. Based on WHO safety reference standard, the fish were polluted with respect to all the metals except Zn and Cr, which was not detected. These metals could pass to humans through the food chain. Cd, Mn, Pb, Zn and Ni are known to be neurotoxic. This may predispose the water and fish consumers to possible neurotoxicity, especially the QIT community. Regular medical checks may be necessary to prevent residual neurotoxicity in the community. Regulatory environmental measures should be put in place to ensure the safety of the estuary and its aquatic life.