Profiling of emerging and legacy per-/polyfluoroalkyl substances in serum among pregnant women in China

Emerging per-/polyfluoroalkyl substances (PFASs), such as chlorinated polyfluorinated ether sulfonates (Cl-PFESAs), have been detected in human samples, yet investigation on their occurrence in pregnant women remains limited. Herein, ten legacy PFASs, branched perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA), two Cl-PFESAs, perfluoro-2-propoxypropanoic acid (HFPO-DA), and ammonium 4,8-dioxa-3H-perfluorononanoate (ADONA) were detected in serum samples from 480 pregnant women in Tianjin, China. The influencing effects of age, body mass index, gravidity, and parity were also evaluated. PFOS [geographic mean (GM): 7.05 ng/mL], 6:2Cl-PFESA (GM: 5.31 ng/mL), and PFOA (GM: 2.82 ng/mL) were the dominant PFASs in the serum of pregnant women, while neither HFPO-DA nor ADONA was detectable in any serum. The serum concentration of Cl-PFESAs and 6:2Cl-PFESA/PFOS ratio in the present study were 2–5 times higher than that in previous studies of pregnant women in China. Serum concentrations of Cl-PFESAs were significantly correlated with all detected PFAAs (Spearman’s Rho: 0.15–0.69, p < 0.01) excepting perfluoropentanesulfonate (PFPeS), indicating common exposure sources for Cl-PFESAs and PFAAs and some particular exposure source for PFPeS. Younger age and multi-parity were associated with lower serum concentrations of PFOS and several perfluoroalkyl sulfonates but not associated with Cl-PFESAs or PFOA, suggesting an increasing exposure to Cl-PFESAs and PFOA which neutralized the impact of age and parity. Overall, this study indicated a relatively high exposure level and composition of 6:2Cl-PFESA in pregnant women in the north coast of China, which highlights the need to investigate the exposure sources in this area.