北京市医院候诊区空气中VOCs的污染特征

对北京市3家医院9个候诊区室内空气进行采样,样品采用预浓缩仪与GC-MS联用系统进行定量分析,共检测出65种挥发性有机物(VOCs).医院室内外VOCs的平均浓度为123.64~713.22μg/m3,其中烷烃、烯烃、芳香烃约占61%~98%.烷烃以乙烷、丙烷、正丁烷、异丁烷、异戊烷为主,占50%以上.烯烃的主要成份为乙烯、丙烯、异戊二烯,约占总烯烃的53%~83%.芳香烃以苯、甲苯、乙苯、二甲苯、苯乙烯为主,约占79%~98%.不同的候诊区芳香烃的组成差异大,病理科候诊区F的芳香烃主要来自二甲苯的贡献(58%±24%),而挂号处G和口腔科候诊区H的甲苯所占芳香烃的比例最大(34%±26%).绝大多数采样点的室内和室外VOCs浓度的比值(I/O)大于1.0,一些候诊区中芳香烃、卤代烃和环烷烃的I/O远大于1.0,表明这些污染物存在一定的室内来源.

Characterization of VOCs in hospital waiting areas,Beijing

Indoor and outdoor air samples were collected from 9 waiting areas of 3 hospitals in Beijing. Sixty-five kinds of VOCs were identified and quantified by the preconcentrator-GC/MS system. The mean concentration of VOCs ranged from 123.64 to 713.22μg/m3. The major components were alkanes, alkenes and aromatics, and they accounted for 61%~98% of the total content. Ethane, propane, n-butane, i-butane and isopentane were the main alkanes (above 50%).The dominating components of alkenes included ethene, propene, isoprene (about 53%~83%).79%~98% aromatics were made up of benzene, toluene, ethylbenzene, xylenes and styrene. The distribution characteristics of aromatics among waiting areas was quite different. Xylenes (58%±24%) were the most important contributor for F waiting area, while toluene was very high in G and H waiting areas. The indoor/outdoor (I/O) ratios of VOCs concentration were above 1.0 in most sampling sites. I/O ratios of aromatics, halohydrocarbons and cyclanes were much higher than 1.0 in some sampling sites, indicating prominent indoor sources.