On the practical significance of electrostatic lung deposition of isometric and fibrous aerosols

Evidence from experiments with humans and animals suggests that the lung deposition of inhaled particles is enhanced if the particles are electrically charged. Simple analysis has been carried out by which the practical significance of the problem can be assessed, based on consideration of the physical factors which influence particle movement under electrostatic image forces in the confined spaces of the alveolar region of the lung. The results support the observations in animal studies that electrostatic enhancement of lung deposition is small for inhaled isometric polydisperse mineral dusts, but potentially large for similarly dispersed fine fibrous asbestos aerosols. From measurements of the levels of electrostatic charging of workplace aerosols, it is concluded that the same will be true for human subjects occupationally exposed to airborne dust.