Changes in Concentrations of Polyfluoroalkyl Substances in Human Milk Over Lactation Time and Effects of Maternal Exposure via Analysis of Matched Samples.

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are potentially related to many adverse health outcomes and could be transferred from maternal blood to human milk, which is an important exposure source for infants during a long-term period. In this study, the maternal blood of 76 women after delivery and their matched human milk samples obtained at 0.5, 1, and 3 months were analyzed by solid-phase extraction method with metal-organic framework/polymer hybrid nanofibers as the sorbents and ultrahigh-performance liquid chromatography-negative electrospray ionization mass spectrometric for quantitative analysis of 31 PFAS. The perfluorooctanoic acid, perfluorooctane sulfonate, and N-methyl perfluorooctane sulfonamido acetic acid (N-MeFOSAA) contributed to more than approximately 50% of the total PFAS concentrations in blood and human milk, while N-MeFOSAA (median: 0.274 ng/mL) was the highest PFAS in human milk at 3 months. The transfer efficiencies for PFAS from maternal blood to human milk at 0.5 months were generally lower, with medians ranging from 0.20% to 16.9%. The number of PFAS species detected in human milk increased as the lactation time went on from 0.5 to 3 months, and the concentrations of 10 PFAS displayed an increasing trend as the prolongation of lactation time (p < 0.05).