ABSTRACT

The bioaccumulation of heavy metals were studied in roasted catfish commonly sold and consumed in Umuahia town of Abia state with the aim of determining their concentration levels. Heavy metals analyzed in the samples include mercury, lead, cadmium and arsenic. Samples were prepared by digesting using standard analytical methods and analyzed for their heavy metal concentrations using an atomic absorption spectrophotometer. Elevated levels were found in all the heavy metals studied; lead cadmium, mercury and arsenic as against universal standards. Lead had a higher level 0.80 ± 0.00 than the regulatory limit 0.01mg/i, which indicates it toxicity in roasted fish analyzed, mercury has a mean value of 0.27 ± 0.00 when compared to regulatory limit 0.002mg/i, and mercury concentration was found to be highly toxic. Cadmium had a mean value of 0.37 ± 0.00; comparison with the standard tolerance value 0.01mg/i reveals the accumulation of cadmium in Clarias gariepinus. Arsenic concentration was found to be 0.32 ± 0.00, when compared with the standard tolerance value 0.05mg/l .The results indicated a significant elevation of heavy metal concentrations over their background values. So the fish we unknowingly consume and assume it to being safe might be contaminated with hazardous toxic heavy metal.