Polybrominated diphenyl ethers in UK human milk: Implications for infant exposure and relationship to external exposure

Fourteen tri-deca polybrominated diphenyl ethers (PBDEs) were investigated in 35 human milk samples from Birmingham, UK. While none of the hepta-nona BDEs (the main components of the octaBDE technical mixture) was above the limit of quantitation (LOQ); BDE-47 (average concentration = 3.3 ng g− 1 lipid weight (lw)) was quantified in all samples contributing 34-74% to Σtri-hexa BDEs (the principal constituents of the pentaBDE commercial formulation). BDE-209 (the main congener in the decaBDE formulation) was present above the LOQ in 69% of samples (average concentration = 0.31 ng g− 1 lw). Concentrations of Σtri-hexa BDEs ranged from 0.2 to 26 ng g− 1 lw with concentrations of BDE-47 > BDE-153 > BDE-99. While concentrations of Σtri-hexa BDEs in this study (average = 5.95 ng g− 1 lw) were at the high end of those reported from other European countries, concentrations of BDE-209 were lower than those reported in human milk from other countries. The average exposure of a UK nursing infant to Σtri-hexa BDEs (35 ng (kg bw)− 1 day− 1) via breast milk exceeded the upper-bound dietary intakes of both UK adults and toddlers. Using a simple one compartment pharmacokinetic model, PBDE intakes of UK adults via inhalation, diet and dust ingestion were converted to predicted body burdens. Predictions compared well with those observed for Σtri-hexa BDEs and BDE-209 in breast milk.