Monitoring and Analysis of the Atmospheric Dust and Aerosol Over Lanzhou City in Spring

The atmospheric aerosol and dust-stormy weathers in Lanzhou City in Spring of 2005 were monitored.In this research the atmospheric aerosol samples were analyzed.The distribution of the mass concentration and color index of atmospheric aerosol were obtained.The largest average mass concentration of TSP was 1.8881mg/m3 from March to April.The relationship between the chroma and the mass concentration under the different weather condition was revealed.During the study of the mass concentration of PM_10 and PM_2.5 particles by Anderson and KB-120E cascade under dust-stormy weather,7th April for example,the distribution law of size grade of PM_10,the proportions of PM_2.5 over PM_10 were got.The average mass concentrations of 100μm and 10μm granules were 1.7011mg/m3 and 1.1043mg/m3 respectively.It was concluded that air pollution of cold weather in Lanzhou City is mainly caused by coal combustion and tail gas from cars and sometimes by dust,too.The different size granule distribution may had different sources.