北京市大气中苯、甲苯污染特征及其影响因子

Influence Factor and Distribution of Benzene and Toluene Concentration in the Atmosphere of Beijing

应用光离子化气体分析仪,采用外标法定量,对北京城市大气中苯、甲苯含量从市郊至市内进行了纵向对比研究,结果 表明:苯质量浓度为9-50 μg·m-3,甲苯质量浓度为20-85μg·m-3。大气中苯、甲苯质量浓度从大到小依次为:四环线、 五环、三环、郊区、二环、市中心天安门。与采样点的车流量状况、气体扩散程度和天气状况等影响因子正向相关。

Benzene and toluene in ambient air from suburb to downtown area of Beijing were measured by GC-PID with external standard method and studied through vertical comparisons where the results indicate that the concentration of benzene and toluene in the air were 9-50μg·m^-3 and 20-85μg·m^-3 respectively. In addition, comparison of the content of benzene and toluene in the air of the following locations is： the Fouth Circle Line, the Fifth Circle, the Third Circle, Suburb, the Second Circle, the centre of downtown atea （Tian＇an Men Square）, which was correspondingly connected with such factors as the traffic flow magnitude, the extent of air diffusion and the weather condition of the locations where samples were taken.