Organochlorine compounds and polycyclic aromatic hydrocarbons in mussels from Ria de Vigo (the Northern Spanish coast). Current levels and long-term trends (2010–2019). Relationship with human pressures

Abstract OCs (organochlorine compounds), such as PCBs (polychlorinated biphenyls) and OCPs (organochlorine pesticides), and PAHs (polycyclic aromatic hydrocarbons) were determined in wild and raft mussels collected in several stations from Ria de Vigo during the period 2010–2019. The concentration levels of Σ PCBs Σ DDs (sum of pp’-DDE and pp’-DDD metabolites) and Σ PAHs ranged from 22.1, 2.63 and 7.55 ng g−1 to 58.0, 6.89 and 25.2 ng g−1 dry weight, respectively. The concentrations of isomers of PCBs in mussel were in the order hexachlorobiphenyls > pentachlorobiphenyls > tetrachlorobiphenyls > trichlorobiphenyls. PCBs 153 and 138 were the most abundant in all samples. Pp’-DDE was the predominant metabolite (70.8% of Σ DDs). The main PAHs in decreasing order of abundance were CHR > BbF > BaA > IcdP. Three biological parameters: lipid content, shell length and condition index have also been investigated. Univariate techniques confirmed that levels of many compounds presented significant relation (p