Dry Lung as a Physical Model in Studies of Aerosol Deposition

A new physical model was developed to evaluate the deposition of micro- and nanoaerosol particles (NAPs) into the lungs as a function of size and charges. The model was manufactured of a dry, inflated swine lung produced by Nasco company (Fort Atkinson, WI). The dry lung was cut into two lobes and a conductive tube was glued into the bronchial tube. The upper 1-2-mm-thick layer of the lung lobe was removed with a razor blade to expose the alveoli. The lobe was further enclosed into a plastic bag and placed within a metalized plastic box. The probability of aerosol deposition was calculated by comparing the size distribution of NAPs passed through the lung with that of control, where aerosol passed through a box bypassing the lung. Using this new lung model, it was demonstrated that charged NAPs are deposited inside the lung substantially more efficiently than neutral ones. It was also demonstrated that deposition of neutral NAPs well fits prediction of the Multiple-Path Particle Dosimetry (MPPD) model developed by the Applied Research Associates, Inc. (ARA).