Different distribution of emerging contaminants in mussels and clams from different areas and their role for food safety

Marine ecosystems are subjected to continuous pollution events because of increasing anthropogenic activities and the releasing of various sources of contaminants (Van De Vijver et al. 2003). Bivalve molluscs are considered good environmental contamination indicators because their tissues accumulate contaminants with little metabolic transformations (Roesijadi et al. 1984; Sericano 1993). Reviewing the presence of contaminant residues is important both for food safety and monitoring of environmental pollution. Here, the occurrence of 6 polychlorinated biphenyls (PCBs), 15 organochlorine pesticides (OCPs), 7 polybrominated diphenyl ethers (PBDEs), 4 polycyclic aromatic hydrocarbons (PAHs) and 17 perfluoroalkyl substances (PFASs) was evaluated in mussels and clams. Multiple species were selected: Mytillus Galloprovincialis, Mytillus Edulis and Mytillus Chilensis for mussels, and Venerupis philippinarum, Perna Canaliculus, Tapes decussatus, Tapes Semidecussatus, Meretrix Meretrix and Meretrix Iyrata for clams. A liquid chromatography-high resolution mass spectrometry (HPLC-HRMS) and an innovative QuEChERS extraction followed by gas chromatography-tandem mass spectrometry (GC-MS/MS) methods were developed, validated and applied. We demonstrate good linearity, repeatability and accuracy of these methods, confirming that these methods are suitable for the analyses of mollusc samples. The prevalence of PCBs, OCPs and PAHs was higher in mussels than clams. For PFASs, the contamination was higher in clams than in mussels. The samples were all compliant with the regulations and, for the compounds without limit, a risk assessment confirmed that the values were lower than the tolerable intake suggested by EFSA