Non-essential toxic element (Cd, As, Hg and Pb) levels in muscle, liver and kidney of loggerhead sea turtles (Caretta caretta) stranded along the southwestern coasts of Tyrrhenian sea.

Non-essential toxic metals are environmental pollutants that contaminate the marine ecosystem due to their extensive use and long-range transport (by rivers and air). Their presence into the environment is often linked to the human activity, with an expected bioaccumulation in the food chain. Within the marine animals, sea turtles may be considered as potential sentinel species for environmental assessment because of their long lifetime, habitat use and migratory nature. In this study, non-essential toxic metals in the coastal of Tyrrhenian Sea were monitored, during the 2017-2018 period, using the Mediterranean loggerhead sea turtle (Caretta caretta) as indicator species. The levels of Cadmium (Cd), Arsenic (As), Mercury (Hg) and Lead, (Pb) were determined in 30 turtles stranded in different locations along the coasts of Campania region of Southern Italy. After morphometric analysis, the non- essential toxic metal accumulation in loggerhead sea turtle muscle and organs have been measured analysing the total concentrations of metals in samples of liver, kidney, and muscle by Atomic Absorption Spectrophotometry (AAS) after microwave assisted digestion with nitric acid and hydrogen peroxide. The pattern of contaminants revealed a similar distribution for Pb and total mercury, that were not significantly high in all the analysed matrices. On the contrary, elevated concentrations of total As were found out in all matrices, mainly in muscle (25.7 mg/kg w.w.), and of Cd in liver (1.23 mg/kg w.w.) and kidney (6.82 mg/kg w.w.). These studies allow us to estimate the exposure degree to which these species are subjected.