The deposition - a modern phenomenon in the evaluation of inhalation risk of mining aerosols

摘要

The deposition is defined as an array of processes causing a part of the inhaled aerosol to remain (after its expiration) in the respiratory tract. The particles retained in the respiratory tract are called deposits. The deposition encompasses of three different mechanisms: impaction, sedimentation and Brown molecular movement combined with the diffusion. The impaction remains the most potential contribution to the deposition in the conductive zone of the respiratory tract. While the sedimentation and diffusion in conjunction with the Brown molecular movement have a major impact in the respiratory area with the zero flow movement. The above listed mechanisms participate with the different ratio to the deposition at respective parts of the respiratory tract. The deposition depends on physical and chemical properties of inhaled aerosols as well as on the susceptibility of each individual. The size, shape, mass, and electric charges are among the basic characteristics of aerosols. The individual susceptibility is mainly influenced by an anatomical arrangement of respiratory tract, tidal volume, frequency of breathing, and breath holding.