[Indoor Exposure to Particle-Bound BFRs via Inhalation]

Size-fractionated atmospheric particles were collected in the closed room, ventilated room and outdoors in a university campus and analyzed for polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane ( HBCDs). The concentrations of particle-bound ∑ PBDE (sum of four PBDE congeners) indoors were significantly greater than those in other regions and similar to the levels in electronic waste recycling sites. In all the samples, BDE209 and alpha-HBCD were the dominant congener for PBDEs and HBCDs, respectively. The size-fractionated distributions of airborne PBDE displayed bimodal peaks in 0.4-0.7 and 5.8-9.0 microm in the closed room, but only a unimodal peak in 4.7-10.0 microm in the ventilated room and outdoors. For HBCD, approximate 90% HBCD were found on coarse particles (aerodynamic diameter (Dr) > 2.1 microm). The inhalation intake of PBDE and HBCD in closed and ventilated rooms were 22.56-1503 pg x (h x kg)(-1), 0.09- 9.25 pg x (h x kg)(-1) and 13.89-601.1 pg x (h x kg)(-1), 0.07-1.75 pg x (h x kg)(-1), respectively. These estimates were much lower than the exposure via dust ingestion suggesting that inhalation of particle-bound BFRs may not be a vital exposure route.