Human health risk assessment for exposure to heavy metals in finfish and shellfish from a tropical estuary

This investigation measured the extent of heavy metal concentrations (Cr, Pb, Fe, Zn and Ni) in nine finfish and shellfish species from a tropical estuary to determine the degree of pollution and evaluate the human health risk from the exposure to heavy metals through consumption of fish. The hierarchy of mean concentrations (mg/kg) of the heavy metals were: Zn (398.47) > Fe (83.015) > Cr (0.906) > Ni (0.233) > Pb (0.128). The metal concentrations in the edible tissues were ranked in the following sequence: A. bato > C. cirrhosus > A. grammepomus > M. dobsoni > P. paradiseus > O. pama > M. rosenbergii > N. smithi > S. phasa. The results demonstrated that the concentration of Cr and Zn was considerably higher than the guideline values of FAO. Estimated daily intake (EDI), hazard quotient (HQ), hazard index (HI), and cancer risk (CR) values were within the acceptable threshold for both adults and children. However, the EDIs of local consumers in the research area for both adults and children were lower than the recommended daily amount (RDA), following the order of Zn > Fe > Cr > Ni > Pb. The HQs of the elements followed the order of Zn > Cr > Fe > Pb > Ni. The investigated HI was not exceeding the recommended limit.