Prenatal Exposure to Per- and Polyfluoroalkyl Substances (PFASs) and Association between the Placental Transfer Efficiencies and Dissociation Constant of Serum Proteins-PFAS Complexes

Information on placental transfer and adverse outcomes of short-chain per- and polyfluoroalkyl substance (PFASs) is limited, and factors responsible for PFAS placental transfer are still unclear. In the present study, concentrations of 21 PFASs were analyzed in 132 paired maternal and cord serum samples collected from Beijing, China, and placental transfer efficiency (PTE) of each PFAS was calculated. PTEs of short-chain perfluoroalkyl acids (PFAAs), including PFBA (146%), PFBS (97%), PFPeA (118%) and PFHxA (110%), were firstly reported, and a complete U-shape trend of PTEs from C4 to C13 of perfluoroalkyl carboxylic acids (PFCAs) were obtained. Positive association between maternal weight and PTE of perfluorooctane sulfonate (PFOS) (p<0.05), and negative association between maternal PFBA concentration and birth length (p<0.01) were observed. Using in vitro experiments, we further determined equilibrium dissociation constants (Kds) of human serum albumin (HSA)-PFAS complexes (Kd-HP), serum proteins-PFAS c...