EVALUATION OF SOME HEAVY METALS IN SELECTED CANNED SARDINE SOLD IN YENAGOA METROPOLIS, BAYELSA STATE, SOUTHERN NIGERIA

Abstract

The content and risk of nine heavy metals (Cd, Ni, Cu, Pb, Mn, Cr, Co, Fe and Zn) were quantified and assessed in canned sardines consumed in Nigeria. The amount of heavy metals in the sardines were assessed with the aid of atomic absorption spectrometry (AAS) after digesting canned sardine samples with mixture of HNO3 and HCl. The quantified content (mg/kg) of the heavy metals ranged from 0.09 – 0.38 for Cd, 0.12– 0.48 for Pb, 0.01 – 1.5 for Cr, 0.06 -1.6 and 0.06 – 1.68 for Mn. The Estimated Dietary Intake (EDI) of Cd varied between 0.12 and 0.53µg/kg bw/day and 0.02 to 0.12µg/kg bw/day for the children and adults respectively. Similarly, the EDI for Pb varied between 0.17 and 0.67 µg/kg bw/day and 0.04 to 0.17µg/kg bw/day for children and adults respectively. For Cr, EDI values obtained ranged between 0.01 – 2.08µg/kg bw/day for children and 0.04 – 0.52µg/kg bw/day for adults. The Target Hazard Quotients(THQs) values of heavy metals for child exposure in canned sardines ranged from 1.20 to
9.31 for Cd, 1.10 to 8.64 for Pb, 1.29 to 9.31 for Cr, 1.40 to 7.51 for Ni, 1.43 to 9.64 for Cu, 1.04 to 5.70 for Mn, 1.29 to 8.86 for Zn, 1.33 to 5.70 for Fe. The EDI values indicated that the intakes of metals from the consumption of the canned sardines were within their provisional tolerable daily intake limits. However, too much consumption of these products could lead to exposure to high amounts of metals