Atmospheric particulate pollutant 0.05㎛-1㎛ in radius reduces effectively the contrast of a distant object by light scattering.
Since the contrast is exponentially decreasing in horizontal line of view as scattering coefficient $b_{sc}$ increases, volume concentration Ø of particulate pollutant 0.05㎛-1㎛ can be deduced from contrast measurement with the approximate relationship between Ø and $b_{sc}$ using Junge number distribution model.
Apparent contrast of Mt. Nam is measured photographically and the volume concentration of 0.05㎛-1㎛ in Seoul is determined. Also, mass concentration M of the total particulate pollutant is calculated with the empirical relationship between M and bsc.
Eolian yellow sand as a natural pollutant in spring time in Asia is studied for identification of its source area, its movement and its transporting characteristics by refering to the weather maps of April, 1980.
