Trace elements and omega-3 fatty acids of black sea (Bulgaria) bivalve species Mytilus galloprovincialis , Chamelea gallina and Donax trunculus . Human health risk.

The study aimed to evaluate trace elements (Cd, Cr, Cu, Fe, Ni, Pb and Zn) concentrations and fatty acids of three Black Sea bivalve species - Donax trunculus, Mytilus galloprovincialis and Chamelea gallina as well as human health risk and benefit-risk ratio based on n-3 LC-PUFA vs. toxic/essential elements. The results showed variations in the element concentrations among the analysed species. D. trunculus generally contained higher levels of the essential elements Cu and Zn, while C. gallina - higher Cr and Fe. Toxic elements content did not exceed the international standards for mollusks. D. trunculus and C. gallina were better dietary sources of n-3 LC-PUFA, with approximately two-fold higher EPA + DHA content than M. galloprovincialis . Health risks for most toxic and essential elements exposed from bivalve consumption were safe based on THQ, HI and TR indices. The benefit-risk ratio indicated that studied species are safe for human consumption, except one case.