Pollution characteristics and source identification of PBDEs in public transport microenvironments

Public transport microenvironments easily accumulate pollutants due to high airtightness and poor circulation. To investigate and analyze the pollution levels and sources of polybrominated diphenyl ethers (PBDEs), air and dust samples were collected from hybrid buses, electric buses and subways in Hangzhou, China. The components of six priority control PBDE congeners (BDE-28, -47, -99, -100, -153, and -209) were analyzed. The average concentrations of Σ₆PBDEs in the air and dust samples were 625.38 pg/m³ and 1200.58 ng/g from hybrid buses; 747.46 pg/m³ and 1160.07 ng/g from electric buses; and 407.57 pg/m³ and 925.93 ng/g from subways, respectively. Decabromodiphenyl ether (BDE-209) was the main proportion of Σ₆PBDEs in the air and dust samples. Several types of materials were collected from the interior as samples to investigate pollutant sources. Using principal component analysis (PCA), it was found that seat cover, polyvinyl chloride (PVC) plastic, rubber, and wire shells were the primary sources. Compared with the reference dose of several PBDE congeners proposed by the U.S. Environmental Protection Agency (US EPA), the exposure level of the population in public transport microenvironments to PBDEs was estimated to be low; however, the potential danger cannot be ignored.