Assessment of elemental contaminants in water and selected seafoods from river Benue, Nigeria

Water, soil sediment and seafood [crab (Sudananautes africanus africanus), lobster (Palaemon paucidens), African catfish (Clarias gariepinus) and African catfish (Synodontis schall)] samples collected from River Benue (Nigeria) were analysed for sodium (Na), potassium (K), copper (Cu), magnesium (Mg), iron (Fe), calcium (Ca), zinc (Zn), lead (Pb), cadmium (Cd), arsenic (As), selenium (Se), chromium (Cr) and phosphorus (P) using standard analytical techniques. Ca had the highest concentration in both water and sediment followed by Mg while the lowest concentrated metal was Pb. Cd was not at the detectable range in both of the samples. When compared the levels of metals in the water and sediment samples, the highest variability was found in Pb (74.55%) and the least was in Fe (0.89%). The lowest concentration was As in all the seafood samples while the highest was Ca ranging between 134.77 – 333.70μgml–1. Pb and Cd were not at detectable range for all the seafood samples. Cu showed the lowest biocentration while Ca was at the highest side of bioconcentration. All values of the bioconcentration factors showed little or no biological magnification of these trace metal concentrations in the bodies of the sea animals. No manifestation of toxic or pollutant effect has been shown and therefore no possibility of deleterious effect was recorded.