无锡市大气中类二噁英多氯联苯污染水平

为了了解无锡市大气中类二噁英多氯联苯(Dioxin-like PCBs,DL-PCBs)水平,利用大流量空气采样器在无锡市分别采集了6个气相和6个颗粒相大气样品,气相色谱-质谱(GC-NCI-MS)测定样品中12种类二噁英多氯联苯。结果显示,大气样品中∑_(12)DL-PCBs的总浓度(气相+颗粒相)为1157～2 747 fg/m³,平均浓度为1759 fg/m3,平均浓度为1759 fg/m³。其中,气相的浓度为11 124～2 721 fg/m3。其中,气相的浓度为11 124～2 721 fg/m³,平均值为1 701fg/m3,平均值为1 701fg/m³;颗粒相的浓度为26～143 fg/m3;颗粒相的浓度为26～143 fg/m³,平均值为58fg/m3,平均值为58fg/m³。气相中∑_(12)DL-PCB含量占总量的97%,而颗粒相仅占3%。DL-PCBs的总毒性当量(气相+颗粒相)为2.16～4.47fg TEQ/m3。气相中∑_(12)DL-PCB含量占总量的97%,而颗粒相仅占3%。DL-PCBs的总毒性当量(气相+颗粒相)为2.16～4.47fg TEQ/m³,平均值为3.53fg TEQ/m3,平均值为3.53fg TEQ/m³。DL-PCBs单体中PCB-118的浓度最高,平均占总浓度的54%,其次是PCB-105和PCB-77,PCB+81在所有样品中均未检出。在所有DL-PCBs中,毒性当量浓度的主要贡献者为PCB-126,其平均贡献率为95%,其次为PCB-169,平均贡献率为3%。

Level of Dioxin-like Polychlorinated Biphenyls in Atmosphere of Wuxi

To assess dioxin-like polychlorinated biphenyls(DL-PCBs) concentration in the atmosphere of Wuxi,Jiangsu Province,6 gas phase and 6 particle phase samples were collected with a modified high volume sampler,and then the 12 DL-PCBs were detected by gas chromatography-negative chemical ionization-mass spectrometry(GC-NCI-MS).Results indicated that total concentrations of DL-PCBs in air samples(gas phase+particle phase) ranged from 1 157 fg/m~3 to 2 747 fg/m~3 with a mean of 1 759 fg/m~3,in which concentrations of DL-PCBs in gas phase samples were 1 124 fg/m~3 to 2 721 fg/m~3, with a mean concentration of 1 701 fg/m~3,accounting for 97%of total DL-PCBs(gas phase+particle phase).The concentrations of DL-PCBs in particle phase samples were 26 fg/m~3 to 143fg/m~3,accounting for 3%of total DL-PCBs(gas phase+particle phase).Total average toxicity equivalent(TEQ) concentration of DL-PCBs in air samples(gas phase+particle phase) was 3.53 fg TEQ/m~3(2.16-4.47 fg TEQ/m~3).PCB-118 had the highest concentration among DL-PCBs,accounting for 54%of total concentration,followed by PCB-105 and PCB-77,PCB-81 was not detected in all of the samples.PCB- 126 was the dominant contributor to TEQ,accounting for 95%,followed by PCB-169 accounting for 3%.