| In Beijing, a large number of products which added Polybrominated diphenyl ethers (PBDEs) and Hexabromocyclododecane (HBCD) as brominated flame retardant are being used. Because of its semivolatile, highly lipophilic, persistent and bioaccumulation, PBDEs and HBCD have been detected in environment media (air, sediment, soil and water) and biological samples. There are no reseach reports about PBDEs and HBCD in the atmospheric environment of Beijing at present. Therefore, the level of PBDEs and HBCD in the atmosphere of Beijing were determined in this reseach, and the preliminary study about the primary temporal and spatial distribution mechanism of PBDEs and HBCD in atmosphere of Beijing were carried out.Atmospheric concentrations (gas and particle phase) of PBDEs (ΣPBDE:BDE-28,-47,-99,-100,-153,-154,-183,-206,-209) ranged from 57 to 469 pg m-3 (average 205 pg m-3) in four seasons of Beijing, and the concentration of BDE-209 ranged from 42 to 387 pg m"3 (average 175 pg m-3), which was the main PBDEs congener and accounted for 82.2% ofΣPBDE; the total the concentrations of HBCD (ΣHBCD:α-,β-,γ-HBCD) ranged from 20 to 1764 pg m-3 (average 390 pg m-3), andα-,β-,γ-HBCD accounted for 27.6,14.3 and 58.0% ofΣHBCD respectively. The research found the total concentrations of PBDEs and HBCD were greatly influenced by the concentration of total suspended particles (TSP) in the atmosphere of Beijing, also temperature was an important factor that affected atmospheric concentrations of lower brominated PBDEs congeners. Emerging from the research, commercial Deca-BDE product was the main source of atmospheric pollution in Beijing with contribution rate as high as 84.9%, while the contribution rate of Penta-BDE and Octa-BDE were 7.6% and 7.4%, respectively. The reseach found that the gas-particle distribution constant (logKp) of BDE-28, BDE-47, BDE-100 and BDE-153 significantly affected by temperature in atmospheric samples in spring, and a significant linear correlation existed between the logKP value and temperature (1000/T), the Pearson correlation coefficients were 0.933 (p<0.002),0.933 (p<0.002),0.895 (p<0.006) and 0.862 (p<0.013) respectively. The results of PBDEs gas-particle distribution model showed that the lower brominated PBDEs congeners changed actively in gas-particle distribution in the atmospheric environment in four seasons of Beijing, while higher brominated congeners were relatively stable in gas-particle distribution.The total concentrations of PBDEs (ΣPBDE) in the tree barks ranged from 99 to 3691 ng g-1 lipid (average 781 ng g-1 lipid), and the concentration of BDE-209 ranged from 95 to 3627 ng g-1 lipid (average 762 ng g-1 lipid), which was the main congener and accounted for 94% of the total amount of PBDEs. The total concentrations of HBCD (ΣHBCD) ranged from 26 to 3438 ng g-1 lipid (average 409 ng g-1 lipid), in whichα-,β-,γ-HBCD accounted for 40.4%～81.8%,10.3%～39.9% and 7.1%～20.4% ofΣHBCD respectively, and the composition was similar to that of commercial HBCD product. AnalysingΣHBCD and EPBDE level distribution in the tree bark samples in different regions of Beijing, the study found PBDEs may be mainly from accumulation electrical and electronic products in Qianhoubajia (QBJ), and the HBCD in Zhenhai Park (ZHP) bark samples may be mainly from the nearby furniture factories and building materials markets. PBDE and HBCD in Gaoantun (GAT) bark samples may be mainly from the local gathered rubbish. In addition, the research found that willow bark was more efficient at accumulation of PBDEs and HBCD in the atmosphere in variety tree bark sampled.Based on the established model and the concentrations of PBDEs and HBCD in the bark samples, the level status of PBDEs and HBCD were estimated in the atmosphere of QBJ, GAT and ZHP where the barks were sampled. The estimate values ofΣPBDE in QBJ, GAT and ZHP were 1830,2096 and 1130 pg m-3, while the estimate values ofΣHBCD were 569,2860 and 526 pg m-3. The results showed that there were the highest level ofΣPBDE andΣHBCD in GAT, followed by QBJ and ZHP, and the lowest one was MZU. |
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