Assessment of trace metal concentrations and human health risk in clam (Tapes decussatus) and mussel (Mytilus galloprovincialis) from the Homa Lagoon (Eastern Aegean Sea).

Seasonal variations of trace metal concentrations (Hg, Cd, Pb, Cr, Zn, and Cu) were investigated in the hepatopancreas and soft tissues (remaining parts of bivalves such as gill, mantle, foot, and muscle) of Tapes decussatus and Mytilus galloprovincialis from the Homa Lagoon. The highest metal concentrations were recorded frequently in February and July in M. galloprovincialis and T. decussatus, respectively. Trace metal levels (except Zn) in the hepatopancreas were higher than those in soft tissue for both bivalves. The results showed that the mean concentrations of Hg, Cd, and Zn for M. galloprovincialis were higher compared to T. decussatus in both tissues. The metal concentrations in both bivalves from the Homa Lagoon were generally below the values of provisional tolerable weekly intake (PTWI) estimates, in terms of human health risk. According to hazard quotient (HQ), Cr values for both species and Cd values for only M. galloprovincialis were found greater than one. Also, total hazard index (THI) values were greater than one in both bivalves, having a potential risk for consumers.