南宁市街区挥发性有机物暴露水平初步分析

通过多层吸附管采样和热脱附-气相色谱-质谱联用对南宁市街区及市郊青秀山的挥发性有机物(VOCs)暴露水平进行了分析.结果显示:南宁市街道大气VOCs中一些毒害性苯系物的质量浓度较高,其中苯、甲苯的平均质量浓度分别达到47.5和159.2 μg/m3,分别是对照点青秀山的2.9和2.0倍;苯及其取代物的特征显示,南宁市街区VOCs主要来自机动车的尾气,同时一些公共活动场所苯系物比值和变化特征有所不同,显示出除交通尾气外的其他来源对挥发性有机物的贡献. 

Preliminary Study on the Exposure Levels of Volatile Organic Compounds (VOCs) in Urban Roadside Microenvironments in Nanning

Exposure levels of volatile organic compounds (VOCs) in air at urban roadsides or plazas in Nanning were determined by multi-bed adsorbent tube sampling followed by thermodesorption-gas chromatography-mass selective detector (TD-GC-MSD) technique. VOCs at Qingxiu Mountain in suburban Nanning were also analyzed in the same sampling period. The results reveal the relatively high levels of monocyclic aromatic hydrocarbons in Nanning. The average mass concentration of roadside levels of benzene and toluene were 47.5 and 159.2 μg/m~3, which were 2.9 and 2.0 times of those at Qingxiu Mountain, respectively. The ratios of benzene (B), toluene (T) and xylene (X) against ethyl benzene (E) showed that vehicle emission was the major source of VOCs in the roadside microenvironments. BTEX at the plazas had different ratios and variations compared to those in roadsides, indicating possible source contributions other than vehicle emission to VOCs at the plazas.