Spatial Variability of Metal Concentrations in Seaweeds, Mussels and Surface Sediments in Gemlik Bay: an Extensive Assessment of Contamination Sources and Associated Health Risks

Surface sediments, mussels, and macroalgae were collected to investigate metal accumulation, distribution, pollution levels, and sources from Gemlik Bay in the southeastern Sea of Marmara. The elements Cu, Zn, V, Co, Cr, Pb, Ni, and Mn were determined in macroalgae (Ulva lactuca Linnaeus,1753), (Ulva intestinalis, Linnaeus, 1753) and mussel (Mytilus galloprovincialis, Lamarck, 1819) samples, while Al and Fe were also determined in sediment samples in addition to these metals. Element accumulation and metal contamination levels were determined, and health risks from mussel and macroalgae consumption were assessed across age groups. The average enrichment factor (EF) calculated for sediment samples indicates that the contamination originates from anthropogenic sources, while the contamination factor (Cf) indicates that the contamination is at a low level. Additionally, the potential ecological risk (Er) and index (PERI) reveal that, except for lead (Pb), the ecological factors for other metals are low. In addition, according to the average geochemical index (Igeo) results, sediments were uncontaminated with Mn and Al, slightly contaminated with Fe, slightly to moderately with Cr and Pb, and moderately with Zn. Detected metals in mussels and macroalgae were assessed for health risks across age groups for the first time. Accordingly, the daily chronic intake (CDI) was calculated, and separate hazard index (HI) and target hazard quotient (THQ) values were determined for each age group. Children were identified as the most vulnerable group, highlighting the need for caution in their consumption of seafood, especially mussels and macroalgae.