Determination of Heavy Metal Levels and Assessment of L. monocytogenes and Salmonella spp. Presence in Fishery Products and Mussels from the Marmara Region, Türkiye

This study evaluated heavy metal levels (Pb, Cd, Hg, As, Cu) and the presence of <i>Salmonella</i> spp. and <i>Listeria monocytogenes</i> in mussels and commonly consumed fishery products from the Marmara region of Türkiye. Health risks were evaluated using total hazard quotient (THQ) and hazard index (HI) values, while microbial risks in fresh and ready-to-eat (RTE) products were estimated via the Risk Ranger tool. Among 625 samples, Hg (36.96%; CI95 = 33.27-48.81), Pb (9.76%; CI95 = 7.67-12.34), and Cd (19.36%; CI95 = 16.45-22.64) exceeded permissible limits, except in crabs, which remained compliant. Anchovy, sardines, bluefish, shrimps, and octopus met EU Cd limits. Shrimps exhibited higher As_in levels than crabs (<i>p</i> < 0.05), while squids had significantly higher As_in than octopus but lower Pb (<i>p</i> < 0.05). Microbiological analysis detected <i>Salmonella</i> spp. in 4.00% of samples (CI95 = 2.50-6.30) and <i>L. monocytogenes</i> in 4.24% (CI95 = 2.70-6.59). Surmullet, bluefish, red mullet, crabs, mussels, and octopus tested negative for both, while anchovy was negative for <i>Salmonella</i> spp. only. THQ and HI assessments emphasized the need for environmental monitoring to mitigate heavy metal contamination. The detection of pathogens highlights the importance of stringent surveillance measures to ensure the safety of fishery products and bivalves.