Concentrations and distributions of PCBs, PBDEs and PCDD/Fs in the atmosphere of Beijing, China

Atmospheric concentrations of polychlorinated biphenyls (PCBs), polybrominated biphenyl ethers (PBDEs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were measured in different seasons from November 2010 to... [ view full abstract ]

Atmospheric concentrations of polychlorinated biphenyls (PCBs), polybrominated biphenyl ethers (PBDEs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were measured in different seasons from November 2010 to March 2012 using passive air samplers to investigate levels and spatial distributions of POPs in the atmosphere of Beijing. The∑19PCBs concentrations varied from 9.6 to 76.7pg m-3 with an average value of 63.26pg m-3. The congener of PCB-28 was predominant in all samples compared to other congener, accounting for 86.3% to∑19PCBs. The summed concentration of 13 PBDEs ranged from 0.91 to 176pg m-3 with mean concentration of 19.4pg m-3. BDE-28, -47, -99, -153 and BDE-183 were predominant congeners, accounting to 58-85% for ∑13PBDEs. The∑PCDD/Fs concentrations were 0.28-3.73pg m-3 with average value of 0.93pg m-3. OCDF (16.7%) and OCDD (27.6%) were predominant congeners. International-toxic equivalents (I-TEFs) of PCDD/Fs ranged from 10.8 to 158 fg I-TEQ m-3 with mean value of 66.9 fg I-TEQ m-3 and 2,3,4,7,8-PeCDF was the main congener, contributing to 44% of the total TEQ. Higher PCBs and PBDEs concentrations were observed in the summer, which can be related to temperature variations. Although the industrial sites showed higher levels of PCBs, PBDEs and PCDD/Fs levels than rural areas, atmospheric concentration of the pollutants in Beijing was relatively low. The results from this study provides further aid in estimating the emission sources of POPs and evaluating the impact of sources and seasonal variations on POPs distributions in mega-cities of China.