Health Risk Assessment of Potentially Toxic Elements, Persistence of NDL-PCB, PAHs, and Microplastics in the Translocated Edible Freshwater Sinotaia quadrata (Gasteropoda, Viviparidae): A Case Study from the Arno River Basin (Central Italy)

With this study we investigated the accumulation of potentially toxic elements (As, Cd, Cr, Cu, Hg, Pb, Zn), six indicators (28, 52, 101, 138, 153, 180) of non-dioxin-like polychlorinated biphenyls (Σ6 NDL-PCBs), polycyclic aromatic hydrocarbons (PAHs), and microplastics in S. quadrata (edible part) collected from two sampling sites (1 and 2) from the Arno River Basin (Central Italy). A risk assessment of the implications for human health was also performed. Levels of potentially toxic elements in gastropods from site 2 were slightly higher and the Σ6 NDL-PCB concentration was significantly higher (7.32 ng g−1 vs. 3.07 ng g−1) compared to site 1 due to higher anthropogenic pressures. The concentration of chrysene, benzo[b]fluoranthene, and benzo(a)pyrene was below the limit of quantification (0.5 μg kg−1). Benzo[a]anthracene was detected in gastropods from both sites (0.5 ± 0.02 μg kg−1 and 0.7 ± 0.02 μg kg−1 from site 1 and 2, respectively). The microplastics frequency (mainly polyethylene terephthalate) differed significantly between the sites (site 1, 0.8 ± 1.30; site 2, 1 ± 0.37 items/specimen). All contaminant levels were compliant with international regulatory limits and guidelines. Incremental lifetime cancer risk (ILCR) values for As, Cd, Cr, and Pb were far below the safety values of 1 × 10–4. Similarly, the ILCR values from the Monte Carlo simulation model were all within the safety region of 1 × 10–4 and 1 × 10–6. Findings from the health risk assessment indicated no adverse effects for human health from any of the contaminants analysed here, except for microplastics for which no limits or legislation are currently in force.