Exposure sources of perfluoroalkyl acids and influence of age and gender on concentrations of chlorinated polyfluorinated ether sulfonates in human serum from China

[Display omitted] •PFCAs and PFSAs in human serum were mainly from direct exposure.•The mean 6:2Cl-PFAES serum concentration was higher than PFOA.•6:2Cl-PFAES concentrations in male serum significantly increased with age.•6:2Cl-PFAES concentrations were positively correlated with PFOS in human serum. The presence of perfluoroalkyl acids (PFAAs) and chlorinated polyfluoroalkyl ether sulfonates (Cl-PFAESs) in humans has attracted great attention in recent decades. However, information on their exposure sources and the influence of age and gender on Cl-PFAES concentrations in human serum is still limited. In this study, eighty-five serum samples were collected from the general population in Anji, China, and analyzed for perfluoroalkyl carboxylates (PFCAs), perfluoroalkyl sulfonates (PFSAs), and Cl-PFAESs. Perfluorooctane sulfonate (PFOS; mean, 5.9 ng/mL) and perfluorooctanoate (PFOA; 3.3 ng/mL) were the predominant PFAAs in human serum. The serum concentrations of C8–C12 PFCAs, perfluorohexane sulfonate, and PFOS were significantly (rs = 0.40–0.98, p