Research on the pollution situation of atmospheric particulates during Autumn in Beijing city

The pollution caused by atmospheric particulates is one of the important factors affecting the urban air quality, which has been the chief air pollutant in many middle-large-sized cities like Beijing in our country. In order to analyze the pollution level and the influence factors of atmospheric particulates in Beijing city, the authors sampled PM10 and PM2.5 at nine areas in Beijing city during autumn in 2005. The spatial distribution and temporal variation features of atmospheric particulates were analyzed through the comparison of the mass concentrations of PM10 and PM2.5 sampled at different areas during different periods, and the influence of meteorological factors was analyzed based on the relationship of the mass concentrations of PM10 and PM2.5 with weather conditions such as temperature, wind speed and relative humidity. The results are concluded as follows. Because of the influence of pollution sources at each sampling area, the mass concentrations of PM10 and PM2.5 in different regions of Beijing city are different from the others, and it also shows that not all the spatial distribution regulations of the mass concentrations of PM2.5 are the same as PM10 on the whole at the same sampling area and the same time. As weather conditions keep stable, the hourly variation of PM10 and PM2.5 concentrations presents regularly, the temporal variation mostly depends on the variety of contaminations released to the environment. Weather conditions are the important influence factors of PM10 and PM2.5 pollution level, the mass concentrations of atmospheric particulates decrease with the rise of the temperature and wind speed, while they increase with the increase of relative humidity.