科研成果

Brominated flame retardants (BFRs) are important persistent organic pollutants. Analysis of BFRs in atmospheric samples in a previous study led us to suspect the presence of unidentified organic bromides, other than polybrominated diphenyl ethers (PBDEs), in the atmosphere. In this study, we identified and quantified polybromobenzenes, a group of organic bromides, in air samples collected through passive sampling in gridded observations in North China. We investigated their concentrations and spatial distribution, and estimated the proportion due to different sources. We detected seven species of polybromobenzenes, including hexabromobenzene (HBB), pentabromotoluene (PBT), pentabromoethylbenzene (PBEB), pentabromobenzene (PeBB), tetrabromobenzenes (TeBBs), and tribromotoluene (TrBT), in all or most of the field samples, indicating widespread occurrence of this class of pollutants. The median concentrations of each pollutant ranged from 20.0 to 144 pg/sample (or from 0.07 to 1.16 pg/m(3)), with relatively high concentrations found near e-waste recycling sites, BFR manufacturing sites, and areas of high population density. Positive matrix factorization (PMF) analysis revealed that similar to 70% of HBB, PBT, PBEB, and PeBB was from commercial products, while similar to 80% of 1,2,3,S-TeBB, 1,2,4,S-TeBB, and 2,4,5-TrBT was linked with BFR manufacturing. This study provides essential information on widespread polybromobenzene pollutants in the atmosphere, particularly TeBBs and TrBT, for which this is the first report of their presence as atmospheric pollutants.