Distribution pattern of legacy and novel brominated flame retardants in different particle size fractions of indoor dust in Birmingham, United Kingdom

This study investigates the particle size distribution of eight polybrominated diphenyl ethers (PBDEs) and five novel brominated flame retardants (NBFRs) in settled house dust. Elevated surface dust (ESD) and floor dust (FD) were collected from 5 homes in Birmingham, UK, yielding a total of 10 samples. Each sample was fractionated into three different particle sizes: 125-250 mu m (P1), 63-125 mu m (P2) and 25-63 mu m (P3). Non-fractionated bulk dust samples (BD) were also analysed. BDE-209 predominated, comprising an average 74.3%, 77.3%, 69.2%, and 62.7% Sigma BFRs of BD, P1, P2 and P3 respectively. Sigma(5)NBFRs contributed 24.2%, 21.5%, 29.0% and 35.3% Sigma BFRs, while Sigma(7)tri-hepta-BDEs represented 1.5%, 1.2%, 1.7%, and 2.0% Sigma BFRs. BEH-TEBP was the predominant NBFR contributing 76.9%, 75.1%, 83.1%, and 83.9% Sigma NBFRs in BD, P1, P2 and P3 respectively; followed by DBDPE which contributed 20.1%, 21.9%, 14.1% and 13.9% Sigma NBFRs. EH-TBB, BTBPE and PBEB were the least abundant NBFRs. Concentrations of Sigma(7)tri-hepta-BDEs and BEH-TEBP in P3 exceeded significantly (P < 0.05) those in P2, with those in P2 exceeding significantly those in P1. In contrast, no significant differences were found between concentrations of BDE-209, EH-TBB, BTBPE, and DBDPE in different particle size fractions. Concentrations of Sigma(7)tri-hepta-BDEs, BDE-209, and BEH-TEBP in ESD exceeded significantly those in FD (P < 0.05). Normalising BFR concentrations to organic carbon content, did not alter these findings. This suggests that differences in BFR concentrations between different particle size fractions are caused by variations in particle surface area to volume ratio, rather than by variations in organic carbon content. (C) 2016 Published by Elsevier Ltd.