Evaluation of Heavy Metals Concentration in Selected Seafood in Ogoni Land

Abstract

Periwinkle, clam, mudskipper, shrimp and catfish are favoured seafood in Ogoni Land. The quantitative estimation of heavy metals in these favoured seafood from Kaa and Kono Rivers have not really been established. This study was undertaken to evaluate the concentration of chromium, iron, lead and cadmium in the aforementioned seafood. Fresh, clean samples of periwinkle, clam, mudskipper, shrimp and catfish were collected from fishermen at landing beaches of Kaa and Kono Rivers. These samples were transported to the chemistry laboratory of Kenule Beeson Saro-Wiwa Polytechnic where digestion was done. Quantitative estimation of heavy metals was done using atomic absorption spectrophotometer at corporate analytical service limited. Analysis showed that all heavy metals in periwinkle are greater than normal guidelines, with the exception of Fe from both rivers and Cr from Kaa. Cr is higher than the normal standards for clam in both rivers, but all others were lower. Except for Fe, all heavy metals in mudskipper exceed acceptable limits for both rivers. For shrimp, Cr and Pb levels are greater than recommended in both rivers, whereas Fe and Cd levels are lower. Cr was not detected in catfish, however Pb and Cd levels are greater than recommended for both rivers, whereas Fe levels are lower. According to a one-time evaluation, periwinkle, clam, mudskipper, shrimp and catfish from Kaa and Kono Rivers have heavy metal concentrations higher than recommended levels for safety. To minimize heavy metal bioaccumulation, these samples should not be consumed for long periods of time. Serial analysis over a long period of time should be carried out in order to provide a more definitive statement concerning the consumption of these seafood.