A Comparison of Trace Gases and Particulate Matter over Beijing (China) and Delhi (India)

摘要

Air pollution represents a significant fraction of the total mortality estimated by the World Health Organization (WHO) global burden of disease project (GBD). The present paper discusses the characteristics of trace gases (O-3, NO, NO2, and CO) and particulate matter (PM10 and PM2.5) in two Asian megacities, Delhi (India) and Beijing (China). A continuous measurement of trace gases and particulate matter are considered from 12 measuring sites in Beijing and 8 sites in Delhi. Over Beijing, the annual average of PM2.5, PM10, O-3, NO2, and CO is, respectively, 85.3, 112.8, 58.7, and 53.4 mu g/m(3) and 1.4 mg/m(3), and, respectively, over Delhi 146.5, 264.3, 24.7, and 19.8 mu g/m(3) and 1.73 mg/m(3). From the spatial variations of pollutants, the concentrations of particulate matter and trace gases are observed to be much higher in the urban areas compared to the suburban areas. The higher average concentrations of PM10 and PM2.5 over Delhi and Beijing are observed during winter season compared with other seasons. The maximum diurnal variation of PM10 concentration is observed during winter season over Beijing and Delhi. The comparison of trace gases shows that the O-3 concentrations during daytime are obviously higher compared with nighttime, and the highest diurnal variation of O-3 is observed during summer. The concentrations of CO are highest during winter season, and higher concentrations are observed during nighttime compared to daytime. The O-3 and CO show negative correlation over Beijing and Delhi. The negative correlation between O-3 and NO2 is merely observed over Beijing, while CO and NO2 concentrations, in contrast, show positive correlation over Beijing.