In Silico Analysis of Deposition Efficiency of Inhalable Metal-Containing Particles in Human Lung Model
HYEON-JU OH, Jongbok Kim,
Seoul National University Abstract Number: 648
Working Group: Health-Related Aerosols
AbstractExposure of the respiratory system to metal oxide particles poses a major impact on human health. However, gaps remain in identifying and evaluating the potential health effects of inhalation exposures, particularly from aerosol components. In this study, we evaluated simulated exposure scenarios by feeding the total number concentration of four metal oxide particles (Iron-, Copper-, Zinc-, and Titanium dioxide) produced within a 100-liter mixing chamber for particle exposure. The metal content of individual particles was analyzed using Energy-Dispersive X-ray Spectroscopy (EDX). The deposition efficiency of these particles was calculated for different breathing patterns at different regions of the respiratory tract using Multiple-Path Particle Dosimetry (MPPD). The size of released particles obtained from metal oxide aerosols is in the range of 30–250 nm in diameter. The respiratory deposition efficiency was found to be lethal in children under 7 years old of age. For children, higher deposition of particles of less than 100 nm in diameter was due to age-dependent breathing patterns and structural and functional characteristics of the lungs. The deposition fraction was 35% higher in children with age < 7 years than in adults at the end of the deep lung (after the 20th lobe generation). To understand different degrees of sensitivity to inhalable particles, it is necessary to consider different deposition efficiency in age groups and the nature of particles deposited in the respiratory tract. We showed that lung particle deposition by age group is determined by the fraction of tidal volume, which may lead to greater lung health risks in children and might be more serious if the particles contain hazardous metals.
This work was funded by the Korean Government through the National Research Foundation of Korea Grant (NRF–2022R111A1A01063383), ICT (NRF-2021R1A2C2004365) and the FRIEND (Fine Particle Research Initiative in East Asia Considering National Differences) Project.