04-11U

A mesoscopic approach for the study of specific features of motion of submicron dust particles in an air environment is considered. An algorithm for numerical solution of the obtained equations of motion in computer experiment is developed. In the context of the presence of radioactive particles of a submicron size in the object "Shelter" (OS), the numerical calculations and estimations of the radioecological risks are performed. It is shown that the flow-electrogravitational mechanism appears to be dominant in transport of dust particles, and the role of the gravitational component decreases with decreasing the sizes of the particles. A special danger presents submicron particles with radius of $R < \sim 100$ nm, which can go out of the OS and migrate on large distances of order 1000 km and more.