Polybrominated diphenyl ethers in UK human milk

24 Fourteen tri-deca polybrominated diphenyl ethers (PBDEs) were investigated in 35 human 25 milk samples from Birmingham, UK. While none of the hepta-nona BDEs (the main 26 components of the OctaBDE technical mixture) were above the limit of quantitation (LOQ); 27 BDE-47 (average concentration = 3.3 ng g lipid weight (lw)) was quantified in all samples 28 contributing 34-74% to Σtri-hexa BDEs (the principal constituents of the PentaBDE 29 commercial formulation). BDE-209 (the main congener in the DecaBDE formulation) was 30 present above the LOQ in 69% of samples (average concentration = 0.31 ng g lw). 31 Concentrations of Σtri-hexa BDEs ranged from 0.2-26 ng g lw with concentrations of BDE32 47 > BDE-153> BDE-99. While concentrations of Σtri-hexa BDEs in this study (average = 33 5.95 ng g lw) were at the high end of those reported from other European countries, 34 concentrations of BDE-209 were lower than those reported in human milk from other 35 countries. The average exposure of a UK nursing infant to Σtri-hexa BDEs (35 ng (kg bw) 36 day) via breast milk exceeded the upper-bound dietary intakes of both UK adults and 37 toddlers. Using a simple one compartment pharmacokinetic model, PBDE intakes of UK 38 adults via inhalation, diet and dust ingestion were converted to predicted body burdens. 39 Predictions compared well with those observed for Σtri-hexa BDEs and BDE-209 in breast 40 milk. 41