PCDD/Fs and PCBs in Mytilus galloprovincialis from a contaminated area in Italy: the role of mussel size, temperature and meteorological factors

Abstract Mussels represent a food at risk of contamination because they are filter-feeding organisms with high bioaccumulation and low biotransformation potential for organic contaminants. Taranto, Southern Italy, is of particular relevance in this context due to the presence of industrial sources of POPs. The aim of this study was to analyse the role of mussel size, temperature and other meteorological factors in determining PCDD/Fs and PCBs concentrations in mussels. Mussels were collected on a monthly basis with random sampling between 2012 and 2020 according to the extraordinary monitoring plan of the Prevention Department. Samples were analysed by the National Reference Laboratory for Halogenated POPs in food and feed. A total of 787 mussel samples were collected between 2012 and 2020. Higher median concentrations were observed in Mar Piccolo First Inlet: PCDD/Fs 1.49 pg WHO-TEQ/g ww; PCDD/Fs + DL-PCBs 6.35 pg WHO-TEQ/g ww; DL-PCBs 4.74 pg WHO-TEQ/g ww; NDL-PCBs 65.10 ng/g ww. In all basins, PCDD/Fs + DL-PCBs, DL-PCBs and NDL-PCBs showed higher concentrations in mussels ≥ 5 cm. Temperature showed positive association with all pollutants in all basins. Higher relative humidity was associated with higher concentrations of some pollutants, while number of rain days was associated with lower values. Our findings showed higher PCDD/Fs and PCBs concentrations in adult mussels, with dependence on temperature and some other meteorological factors. These results could help guide public health strategies and mussel sampling according to mussel size and meteorological conditions in areas affected by POPs contamination.