Accumulation of Heavy Metals (Fe, Mn, Cu, Zn, Ni, Pb, Cd and Cr) in Tissues of Narrow-barred Spanish mackerel (Family-Scombridae) Fish Marketed by Karachi Fish Harbor

Abstract

In the present study, Scomberomorus commerson was collected during the period 2006-2011 in order to provide information on the concentrations of eight heavy metals present in this marine species commonly consumed by the population and to have knowledge whether these levels may constitute a hazard to consumers. Liver showed high concentrations of metals in the tissues and organs. Fe is the most accumulated in all tissues and organs. The highest mean concentration of Fe (608.93+113.22 µg/g), Mn (9.79+4.22 µg/g), Cu (38.57+16.62 µg/g), Zn (53.25+26.50 µg/g), Ni (3.22+1.13 µg/g), Pb (1.20+0.64 µg/g), Cd (2.03+0.91 µg/g) and Cr (1.93 + 0.87 µg/g) was determined in liver of fish. The order of abundance of the metals in the fish samples based on concentrations in the muscle tissues analysed were as follows: Fe>Zn>Cu>Mn>Ni>Cd>Pb≥Cr. For the toxic metal, Pb was found to have lower concentration of the mean values than the permissible limits set by FAO/WHO. However, Cd level was higher than the permissible limit and it can be concluded that the contamination of Cd in S. commerson may pose threat for the importers due to high per capita consumption of the fish.