Per- and polyfluoroalkyl substances exposure through human milk, health risk assessment and physical growth in one-year-old children in Shandong, China

Abstract

Breastfeeding is an important source of Per- and polyfluoroalkyl substances (PFAS) exposure for breastfed infants. However, compared to prenatal exposures, health effects related to postnatal exposure to PFAS are less studied. In this study, we investigated PFAS exposure risk via breastfeeding and evaluate their associations with the physical growth of one-year-old infants in Laizhou Wan, a region with high PFAS exposure in Shandong, China. We included 117 mother-infant pairs who provided both human milk and maternal plasma samples for PFAS measurements. Among them, 99 one-year-old children were followed up for anthropometry measurement. We found that both legacy PFAS and their alternatives were widely detected in human milk samples. PFAS can be transferred from maternal serum to human milk. Perfluorooctanoic acid (PFOA) (median: 0.970 ng/mL) was the dominant PFAS compound in human milk, while perfluoro-6-methylheptanoic acid (6 m-PFOA) (0.013 ng/mL) and 6:2 chlorinated polyfluoroalkyl ether sulfonate (6:2 Cl-PFESA) (0.018 ng/mL) had the highest median concentrations among branched isomers and alternatives, respectively. PFOA (77.35 ng/kg bw/d) had the highest median estimated daily intake (EDI) and contributed the most to the total median EDI of the Σ4PFAS (82.26 ng/kg bw/d). The daily exposure of infants to PFAS through breastfeeding has exceeded the health-based guidance value (HBGV) set by the European Food Safety Authority (EFSA) and the Agency for Toxic Substances and Disease Registry (ATSDR). Sex-specific effects might exist in the association between infants' physical growth and PFAS exposures via human milk, with the PFAS mixtures showing negative associations with height-for-age z-score (HAZ) (β = −0.49, 95 % CI: −0.92, −0.06) and head circumference-for-age z-score (HCZ) (β = −0.61, 95 % CI: −1.02, −0.20), and a positive association with body mass index-for-age z-score (BMIZ) (β = 0.73, 95 % CI: 0.02, 1.44) only in female infants. Further longitudinal studies are warranted to verify our results.