Evaluation of the current contamination status of PFASs and OPFRs in South Korean tap water associated with its origin

Highlights: • We investigated the current PFAS and OPFR contamination status of tap water in South Korea. • ∑PFAS levels, and the contribution of PFHxS to ∑PFASs, in tap water have increased since 2012. • Differences in PFAS levels, but not OFPR levels, by region and tap water origin were found. • High PFAS levels were found in river-originating tap water, which was not the case for lake/reservoir-originating tap water. We investigated the concentrations of perfluoroalkyl substances (PFASs) and organophosphate flame retardants (OPFRs) in 44 tap water samples, collected from eight major cities in South Korea served by four representative watersheds, to evaluate the water contamination status. The total concentrations of PFASs and OPFRs ranged from 1.44 to 224 ng/L (median = 11.9 ng/L), and 74.0 to 342 ng/L (median = 151 ng/L), respectively. The predominant compounds in tap water were perfluorohexane sulfonate (PFHxS), perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), tris(2-chloroethyl) phosphate (TCEP), tris(chloroisopropyl) phosphate (TCIPP), and tris(2-butoxyethyl) phosphate (TBOEP). Tap water originating from the Nakdong River within an industrial complex showed a notably higher PFHxS proportion to total PFASs. In addition, significantly higher PFAS levels were found in river-originating tap water than in lake/reservoir-originating tap water (Mann-Whitney U test, p < 0.05). Meanwhile, major OPFRs showed no clear difference in distribution by region, and no significant difference in major OPFR levels was observed according to tap water origin. Finally, the average human exposure via tap water consumption was estimated for PFASs (46.8 ng/person/day) and OPFRs (254 ng/person/day).