Burden of per- and polyfluoroalkyl substances (PFAS) in human breast milk: Implications for maternal and infant health

Per- and polyfluoroalkyl substances (PFAS) are frequently detected in human breast milk. However, there is still limited understanding of the potential health risks associated with PFAS contamination in breast milk. In the present study, we calculated the plasma concentrations and estimated daily intakes (EDIs) of four PFAS, i.e. perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS) and perfluorononanoic acid (PFNA), based on a recently published study on PFAS concentrations in breast milk from five regions of the United Nations, and evaluated the potential health risks of PFAS. Risk assessment based on plasma PFAS concentrations indicated their potential deleterious effects on both mothers and infants, and notably infants were more vulnerable than mothers to PFAS exposure. Moreover, PFHxS and PFNA posed a higher health risk than PFOS and PFOA. Based on the calculation of toxicological data from animal studies using the method proposed by the Agency for Toxic Substances and Disease Registry (ATSDR), new minimal risk values (MRVs) proposed herein for infants were 3.35, 2.92, 0.25, and 0.38 ng/kg bw/d for PFOS, PFOA, PFHxS, and PFNA, respectively. The comparison of infant MRVs and EDIs further demonstrated the health hazards of PFAS exposure in infants via breast milk. This work indicated the potential maternal and infant health risks from human burden of PFAS, and the newly developed MRVs of four PFAS for infants would be more suitable than the health-based guidance values proposed by the ATSDR, in view of accurate assessment on the health threat to neonates from the exposure of this kind of emerging chemicals via breastfeeding.