Electrostatic charge effect on respirable aerosol particle deposition in a cadaver based throat cast replica

This study investigated the integrated effects of particle size and electrostatic charge on the deposition of inhaled aerosol particles in a polyester resin cadaver based throat cast replica (TCR). Many lung diseases are associated with exposure to atmospheric dust particles and other pollutants. The most harmful respirable particles are smaller than 5 μm in size which efficiently reach the alveolar region. Since the human throat is an effective filter, we devised a novel idea of charging particles and studying their deposition in the TCR. Aerosol particles were generated from a commercially available nebulizer and charged by a corona charger. Their size and charge distribution were characterized by an Electronic Single Particle Aerodynamic Relaxation Time (ESPART) analyzer. Charged and uncharged particles were allowed to pass through a polyester resin cast of a cadaver based throat, a replica of a human oropharyngeal region. Again their size and charge distribution were characterized. The study results revealed that charging the particles increased agglomeration of smaller (aerodynamic diameter, da < 5 μm) particles and increased deposition from 9 ± 0.5% to 31 ± 0.5%. It also showed that the deposition of charged particles increased with increasing particle size. Electrostatically charging and depositing particulate matters prior to entering into the tracheobronchial region are discussed.