Analyses of volatile organic compounds concentrations and variation trends in the air of Changchun, the northeast of China

The concentrations of volatile organic compounds (VOCs) were monitored from September 1997 to July 1998 at five different function zones in Changchun, the northeast of China. The VOCs levels by the roadside (the center zone of the main street) and in the downtown area were higher than those in other three areas, with the lowest concentration observed at rural site. A seasonal variation of VOCs in all sampling sites was observed, with the maximum in winter and the minimum in spring. The diurnal variation of the total mean VOC concentrations showed two peaks related with traffic density for the A, B and D sites, and a single peak for the industrial area.