Atmospheric admixture deposition on the earth surface

The review of the investigations of the physico-chemical processes conditioning radioactive and nonradioactive admixtures removal from the atmosphere on the Earth surface is presented. The admixture is removed with the dust during its gravitational deposition, turbulent and Brownian diffusion, by the admixture washout from the atmosphere with clouds and precipitation and the formation of ground condensation products by the interaction of the admixtures with the earth and water surfaces and vegetative cover. The main role in the admixture removal from the atmosphere is played by the admixture washout with clouds and precipitation, as the dry admixture deposition is on the average only from 20 to 40%. The values of wet and common admixture removal are estimated by measuring the admixture removal coefficient or their residence time in the atmosphere. Several tasks necessary to solve for the evolution and understanding of the processes of the admixture removal from the atmosphere are innumerated. When analysing dry admixture deposition on the earth surface, it is essential to investigate the interaction of the deposited admixtures with the earth surface. When analysing the wet washout mechanisms, it is necessary to investigate the air filtration through clouds and the aerosol capture by the falling drops