Heavy Metal Accumulation and Human Health Risk in Mediterranean Mussels from the Southern Marmara Sea, Türkiye

This study evaluated the accumulation of heavy metals (As, Cd, Cu, Hg, Pb, and Zn) in Mediterranean mussels (Mytilus galloprovincialis) collected from five coastal stations (Küçükkumla, Kurşunlu, Güzelyalı, Mudanya, and Zeytinbağı; n = 20 mussels per station; composited into one sample per site) along the southern coast of the Marmara Sea (Bursa, Türkiye), and assessed the associated potential health risks. Analyses using ICP-OES revealed spatial variations in metal concentrations among stations. Statistical analyses (p < 0.05) showed no significant differences in As levels, whereas Cd, Cu, Hg, Pb, and Zn concentrations differed significantly. Mudanya exhibited the highest levels of Zn and Hg, while Cd was particularly elevated in Mudanya and Güzelyalı. Kurşunlu showed the highest Cu concentrations, and Küçükkumla had the highest Pb levels. Human health risk assessments for the adult population (EDI, EWI, THQ, HI) were all below 1.0, indicating no appreciable non-carcinogenic risk under the assumed adult dietary exposure scenario, based on internationally recognized toxicological reference values (FAO/WHO, JECFA, and EC Regulation 1881/2006). However, relatively higher HI values in Mudanya (0.695) and Küçükkumla (0.646) suggest the need for closer monitoring. Overall, the findings demonstrate that mussels serve as effective bioindicators of coastal metal contamination in the southern Marmara Sea and underscore the importance of continuous biomonitoring to safeguard both ecosystem and public health.