ASSESSMENT OF HEAVY METAL CONCENTRATION IN SEDIMENT AND FISH (Oreochromis Niloticus AND Clarias Gariepinus) IN BONNY ESTUARY, NIGER DELTA, NIGERIA, AND THEIR HUMAN HEALTH IMPLICATIONS

This study was carried out to examine the concentration of heavy metals in fishes, sediments, and their associated human health implications from Bonny Estuary, Rivers, Nigeria. A total of twenty-four (24) fish specimens and four (4) sediment specimens were gathered and tested using standardized procedures for essential and non-essential trace metals. Simple descriptive and inferential statistics were used to analyze the data. In fish specimens, health risk indices for both carcinogenic as well as non-carcinogenic impacts of heavy metals were evaluated. The result of metal concentrations in Oreochromis niloticus and Clarias Gariepinus revealed Pb (10.88±3.24 to 37.12±0.42 mg/kg) and Cd (0.94±0.66 to 1.16±0.10 mg/kg) were greater than Food and Agriculture Organization allowable limits. The bioaccumulation variable revealed Pb as the greatest metal accumulator in both O.niloticus and C.gariepinus from sediment specimens. Pb had a hazard quotient (HQ) greater than 1.0, indicative of non-carcinogenic side effects. Cancer Danger (CR) values of Lead (Pb) in Oreochromis niloticus varied from 1.1 × 10−2 to 2.7 × 10−2, while those in Clarias gariepinus ranged from 1.5 × 10−2 to 3.3 × 10−2, showing that both breeds are carcinogenic. The CR values of Cd were as well discovered to surpass the standard parameters of 1.0 × 10−4. The results of this study reveal worrisome levels of Pb and Cd, which need an immediate awareness and quick response to mitigate their associated health risk.