Occurrence and dietary exposure of perfluoroalkyl substances (PFAS) in marine and livestock products in South Korea

Abstract

19 perfluoroalkyl substances (PFAS), which include both perfluoroalkyl acids, PFAAs, and precursor compounds, were investigated in marine and livestock products in South Korea in this study. Precursor compounds which are less toxic and persistent than PFAAs undergo abiotic and biotic biodegradation to the more persistent and toxic PFAAs. Although highest concentrations of total PFASs were found in pacific oyster, anchovy was the highest contributor to estimated daily intake (1.23 ng/kg/day). Furthermore, a shorter chain compound, PFHxA contributed 26.3% to the total ionic PFAS concentration, FHEA contributed 36.7% to the precursor compounds. Strong significant correlations were observed among PFAA and precursor compounds indicating co-exposure of these compounds, and also supporting the hypothesis of biodegradation of these compounds. Estimated human daily exposure levels for PFOS and PFOA were 1.11 ng/kg bw/day and 1.47 ng/kg bw/day respectively. These values were lower compared to previous studies and they were also lower compared to the recommended tolerable daily. While marine products were the major contributors to dietary exposure to PFAAs, livestock products were found to be the major contributors to dietary exposure of precursor compounds. This difference could be related to the different exposure routes of these samples to these compounds.