Gridded field observations of polybrominated diphenyl ethers and decabromodiphenyl ethane in the atmosphere of north China.

Brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs) are important pollutants, yet few data on ambient BFRs levels have been available for North China, one of the most developed regions of the country. In this study, we investigated levels and spatial distributions of BFRs based on gridded field observations coupled with passive air sampling in the aforementioned region. A model incorporating both point and nonpoint sources was developed to simulate the spatial distribution and to achieve source apportionment. Although high concentration was observed at an electronic-waste (e-waste) recycling site, the median level of the sum of tri-, tetra-, hepta-, hexa-, and hepta-PBDEs (∑10PBDEs) was 0.56 ng/sample, which was lower than those observed previously in mainland China. Source apportionment revealed that nonpoint emissions contributed nearly 78% of ∑10PBDEs observed in this study. In contrast, high levels of BDE-209 and DBDPE were observed, with median concentrations of 4.0 and 10.2 ng/sample, respectively. Point sources located in the region around Laizhou Bay, Shandong Province were the major sources, which contributed 31% of BDE-209 and 70% of DBDPE observed in this study, indicating that this manufacturing base was the most important source region for atmospheric deca-BFRs in North China. To our knowledge, this is the first study to report source apportionment of atmospheric BFRs based on gridded field observations.