Occurrence and pattern of legacy and emerging per- and Poly-FluoroAlkyl substances (PFAS) in eggs of loggerhead turtle Caretta caretta from western Mediterranean.

ABSTRACT

Per-and Poly-FluoroAlkyl Substances (PFAS) are a class of persistent, toxic, and mobile and chemicals both from industrial sources and from the use and disposal of Consumers products containing PFAS, whose concentration in marine food webs could pose a toxicological risk for biota and humans. In 2021, unhatched eggs were sampled from 41 loggerhead turtle Caretta caretta nests from the Italian shores of the Campania Region (Southern Italy). Whole eggs were analysed for the presence of 66 legacy and emerging PFAS with Liquid Chromatography coupled to Hybrid High Resolution Mass Spectrometry. A median Σ66 Per- and Poly-FluoroAlkyl Substances value of 3.34 ng/g egg fresh weight was found; perfluoroctane sulfonate (PFOS) represented the most contributing congener (47%), followed by perfluoro-n-undecanoic acid, perfluoro-n-tridecanoic acid, perfluoro-n-decanoic acid, perfluoro-n-decanoic acid, and perfluoro-n-tetradecanoic acid, respectively. Such compounds showed a log-norm distribution, suggesting found concentrations could represent the baseline levels in the considered sampling area. Emerging ChloroPolyFluoroPolyEthers Carboxylic Acids (ClPFECAs) were found in 20 out of 41 samples in the range 0.01-1.59 ng/g. Four samples had 20-100 fold higher concentration compared to that of other samples, suggesting the presence of hot spot areas possibly related to presence of fluoropolymer-based marine litter turtles may ingest. The analysis of two paired eggs/liver samples recovered from stranded animals revealed PFAS concentration in the same order of magnitude, supporting the role of vitellogenin in their selective transfer to yolk. Significant (P = 0.0155) Kendall negative correlation coefficient of -0.2705 among PFOS content in eggs and the recorded hatching success prompts for further investigation on associated exposure assessment and related eco-toxicity risk. This work reports for the first time PFAS presence in georeferenced loggerhead turtle eggs of the Mediterranean Sea and results represent a starting point to study PFAS time-trends in this vulnerable species.