Seasonal distribution, gas–particle partitioning and inhalation exposure of brominated flame retardants (BFRs) in gas and particle phases

Abstract Background Atmosphere is one of the sources and sinks to gas- and particle-bound brominated flame retardants (BFRs). Therefore, BFRs can enter human body via inhalation. In the present study, 79 of gas- and particle-phase samples (TSP, PM 10 and PM 2.5 ) were collected during 2015–2016 in urban area of Shanghai, China to investigate the occurrence of 25 polybrominated diphenyl ether (PBDEs) congeners, hexabromobenzene (HBB) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE). Results The total concentrations of BFRs ranged from 0.66 to 13.7 pg/m 3 , 25.82 to 376.27 pg/m 3 , 14.58 to 365.49 pg/m 3 and 15.17 to 304.89 pg/m 3 in gas, TSP, PM 10 and PM 2.5 , respectively. HBB was the main compound in gas phase; while BDE-209 was the dominant congener in particle phase. Atmospheric BFRs in winter was much lower than in summer, while particle phase showed opposite seasonal tendency. Conclusions Clausius–Clapeyron equation suggested that BTBPE, BDE-28, -66, -99, -100, and -154 were more driven by temperature and evaporated from local contamination. Higher-brominated congeners tended to be absorbed in particle phase, while low-brominated compounds partitioned in both gas and particle phases. Gas/particle partitioning results showed that absorption into the aerosol organic matter was the dominant process for BFRs. The inhalation health risk assessment demonstrated that the hazard quotient (HQs) for most PBDEs in winter was higher than in summer.