| Polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs),polychlorinated biphenyls(PCBs) and polybrominated diphenyl ethers(PBDEs) are groups of persistent organic pollutants(POPs) that are widely distributed in the environment,which means they are stable in the environment,accumulated in the fatty tissue of living organisms and show high toxicity at very low levels.The studies on PCDD/Fs and PCBs in autumn in Beijing showed the mean mass concentrations of PCDD/Fs and PCBs in PM10 were 2.405 and 1.480 pg /m3,and mean toxic equivalent were 105.6 and 1.62fg/m3.The mean mass concentrations of PCDD/Fs and PCBs in PM2.5 were 1.663 and 0.963 pg/m3,and mean toxic equivalent were 75.3 and 1.01fg/m3.OCDD,OCDF and 1234678-HpCDF were dominant monomers in PCDD/Fs,PCBs dominant monomer was PCB-209,PCB-28 and PCB-138.The spatial distribution of mass concentration of PCDD/Fs and PCBs in autumn showed that industrial fuel and traffic were main source contributions to the pollution. During the traffic limitation,the mass concentrations of PCDD/Fs and PCBs in PM10 were 0.498 and 0.442 pg/m3 respectively,while the mass concentrations of PCDD/Fs and PCBs in PM2.5 were 0.429 and 0.327 pg/m3 respectively.And it is concluded that the characteristic monomer of PCDD/Fs from traffic was OCDD;the characteristic monomers of PCBs were PCB-209 and PCB-28.The pollution level,spatial distribution and source of PBDEs from atmospheric particulates PM2.5 and PM10 in Beijing were analyzed as well.The mass concentrations of PBDEs in PM2.5 were in the range of 2.25～57.94 pg/m3 with mean value of 12.84 pg/m3, the mass concentrations of PBDEs were in the range of 2.50～67.98 pg/m3 with mean value of 23.50 pg/m3.The mass concentration of PBDEs in winter is higher than that in autumn. Monomer distribution of PBDEs in PM2.5 samples is different,and the mass concentrations of penta-BDE and hexa-BDE are higher than those of tetra-BDE and tri-BDE.The PBDEs pollution are generally from traffic,industrial fuel and fire retardant.The contribution to PBDEs pollution is fire retardant,industrial fuel,traffic in descending order.
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