THE RELATIONSHIP BETWEEN VISIBILITY AND AIR POLLUTION IN BEIJING
Su Weihan Zhang Qiupeng Shen Ji Yin Xingjun Song Wenzhi Li Sanmin Lu Hongrong Lo Chao(Institute of Environmental Chemistry, Academia Sinica)
The air pollution field experiment was conducted at 11 stations of Beijing area in the autumn and winter of 1981. Sulfate, total particulates, sulfur dioxide, concentration of particulates with diameter between 0.3 and 10 μ, visibility and other meteorological data were collected twice with ten days for each. The relationship between visibility and air pollution in Beijing area shows that during the period of ten years (1970 -79), the mean visibility was decreased by 6-10 Km and ,the frequency of visibility less than 4 Km in winter was increased by 10 times. The field experiment has indicated that the increasing of concentration of sulfate and particulates, relative humidity, and the number of particulates of 0.3-10 μ would decrease the visibility. Sulfate is one of the most sensitive parameters which reduce the visibility, especially the synergistic effect with humidity. It is suggested that the structure of energy source be improved, the standards of emission and ambient concentration of pollutants be set up in order to improve visibility while the consumption of energy source has been increasing.