Prenatal exposure and transplacental transfer of perfluoroalkyl substance isomers in participants from the upper and lower reaches of the Yangtze River

Data on gestational exposure characteristics and transplacental transfer are quite limited for perfluoroalkyl substance (PFAS) isomers, especially those from large-scale comparative studies. To fill this gap, we examined isomers of perfluorooctane sulfonic acid (PFOS), perfluorooctanoic (PFOA), perfluorohexane (PFHxS) in matched maternal cord serum Mianyang Hangzhou, which located the upper lower reaches Yangtze River, China, respectively. These data were compared with our previous study Wuhan middle reach. The average ?PFAS concentration increased upstream to downstream (Mianyang (4.44 ng/mL) < (9.88 Hangzhou (19.72 ng/mL)) may be related per capita consumption expenditure each city. ln-transformed PFAS concentrations showed significant differences between after adjusting confounding factors (p 0.05). percentages linear PFOS PFOA these cities all exceeded electrochemical fluorination products. isomer profiles PFASs might greatly influenced by local production processes residents’ dietary habits. efficiencies decreased significantly increasing ?PFAS, ?PFOS, ?PFOA, ?PFHxS, n-PFOS, iso-PFOS, 4m-PFOS, 1m-PFOS, n-PFOA, n-PFHxS, br-PFHxS (Spearman rank correlation coefficients (r) = 0.373–0.687, p 0.01). findings support an understanding regional along isomeric regions, isomers.