Bioaccumulation of DDT, PCBs, PBDEs, PAHs, synthetic fragrances, PFASs and mercury in molluscs of Lake Maggiore (North Italy) and in fish of its main tributaries

Lake Maggiore is a southern subalpine lake located across the border between Italy and Switzerland. It is well studied since 1972 thanks to a monitoring program funded by the International Commission for the Protection of Italian-Swiss Waters (CIPAIS; https://www.cipais.org/web/). This program comprises the analysis of trace elements and persistent organic pollutants (POPs) in sediments of the lake and of the main tributaries and in different bioindicators: zooplankton, lake molluscs, riverine benthic invertebrates, and fish. This lake is characterized by legacy DDT and mercury contamination deriving from industrial activities. However, several different anthropogenic pressures act as potential sources of contamination. The present dataset (on excel file) consists of data regarding the analysis of POPs and mercury in two species of fish - Salmo trutta and Squalius squalus – sampled annually in four tributaries of Lake Maggiore between 2022 and 2024: Toce, Boesio, San Giovanni and Margorabbia rivers. Analyses were performed on pools of caudal fillets taken from fish specimens with similar body size. Besides, the dataset comprises data of POPs and mercury concentrations in Mollusca Bivalvia Unio elongatulus, Corbicula fluminea and Dreissena polymorpha sampled annually in Lake Maggiore at 8 different sites between 2022 and 2024. Analyses were performed on soft tissue of pools of specimens with similar shell size. The reported contaminant concentrations comprise: - Dichlorodiphenyltrichloroethane (DDT): 6 congeners and isomers (o,p' DDD, p,p' DDD, o,p' DDE, p,p' DDE, o,p' DDT and p,p' DDT) and total DDT. - Polychlorinated biphenyls (PCBs): 14 congeners (PCB-18, -28+31, -44, -52, -101, -118, -138, -149, -153, -170, -180, -194, -209), and sumPCB14; - Polybrominated diphenyl ethers (PBDEs): 8 congeners (BDE-28, -47, -99, -100, -153, -154, -183, -209) and sumBDE; - total mercury (THg) and methylmercury (MeHg); - Polycyclic musk fragrances (PMFs): ADBI (Celestolide), AHDI (Phantolide), HHCB (Galaxolide), AHTN (Tonalide), HHCB-L (Galaxolidone), and sumPMFs; - Perfluoroalkyl and polyfluoroalkyl substances (PFASs): Perfluorooctane sulfonate (PFOS), Perfluorooctanoic acid (PFOA), Perfluorobutanoic acid (PFBA), Perfluorobutanesulfonate (PFBS), sum of PFAS (sum of PFOS, PFOA, PFBA and PFBS) and sum of the concentration of Perfluorodecanoic acid (PFDeA), Perfluorododecanoic acid (PFDoA), Perfluoroheptanoic acid (PFHpA), Perfluorohexanoic acid (PFHxA), Perfluorohexasulfonic acid (PFHxS), Perfluorononanoic acid (PFNA), Perfluoropentanoic acid (PFPeA) and Perfluoroundecanoic acid (PFUnA) expressed as sum of other PFAS compounds; - Polycyclic aromatic hydrocarbons (PAHs): 17 congeners (Naphthalene, Acenaphthylene, Acenaphthene, Fluorine, Phenanthrene, Anthracene, Fluoranthene, Pyrene, Benzo[a]anthracene, Chrysene, Benzo[b]fluoranthene, Benzo[k+j]fluoranthene, Benzo[a]pyrene, Perylene, Indeno[1,2,3-cd]pyrene, Dibenzo[a,h]anthracene, Benzo[ghi]perylene) and sumPAHs; - lipidic content. The dataset of the lacustrine molluscs allows for detecting changes in the concentrations over the analysed period and between different areas of the Lake, thus providing evidence for spatial and temporal variations of pollutants and expected temporal trends of contamination (see annual reports on hazardous substances in Lake Maggiore at https://www.cipais.org/web/). Data on fish collected in tributaries provide a basis for identifying contamination sources and pathways along the trophic chain and for evaluating potential risks for the ecosystem and for human health due to fish consumption. This research was funded by the International Commission for the Protection of Italian-Swiss Waters (CIPAIS), monitoring program 2022-2024 (https://www.cipais.org/web/).