Polybrominated biphenyl ethers in breast milk and infant formula from Shanghai, China: temporal trends, daily intake, and risk assessment.

To investigate the temporal trend of polybrominated diphenyl ethers (PBDEs) in breast milk and assess the risks to breast- and formula-fed infants, breast milk and infant formula samples were collected from Shanghai, China. The PBDE concentrations decreased from 14.8 to 4.85 pmol/g lipid weight during 2006-2012, with a rate of decrease by half approximately every four years. Although there were no significant correlations between the total PBDEs in breast milk and age, parity, and pre-pregnant BMI of mothers, there were significant differences between primiparous and multiparous mothers for tri- to hepta-BDEs. PBDEs in breast milk were much higher than those in infant formula (equivalent to 91.9 vs. 5.25 pg/mL). Among the different brand infant formulas, there were no significant differences in their PBDE concentrations. The estimated daily intake of PBDEs by breast- and formula-fed infants suggested that breast-fed infants are exposed to much more PBDEs than formula-fed ones (12.9 vs. 0.72 ng/kg-bw/day). However, the hazard quotient values were much smaller than one, indicating that the ingested PBDEs did not exert obvious adverse effects on both breast- and formula-fed infants considering non-carcinogenic effect endpoint. This is the first report on temporal trend of PBDEs in breast milk from China.