Aging effects on airflow distribution and micron-particle transport and deposition in a human lung using CFD-DPM approach

Understanding the transportation and deposition (TD) of inhaled aerosol particles in human lung airways is important for health risk assessment and therapeutic efficiency of targeted drug delivery. The particle TD into a human lung depends on lung anatomy, breathing pattern, as well as particle properties. The breathing capacity and lung airway diameters can be reduced by about 10% every 10 years after the age of 50. However, the age-specific particle TD in human lungs, particularly in the aged, has not been well understood in literature. This study investigates the particle TD in the lungs of people aged 5070 years, using computational fluid dynamics (CFD). A new cutting method that splits the lung model into different sections has been developed as a feasible CFD method to simulate the particle TD in G0 to G14 lung airways. The inhalation of micron scale particles with three diameters (5 mu m,10 mu m and 20 mu m) and a constant air flow rate in inhalation is considered. It is found that different sized particles are deposited in different generation airways. Nearly 100% of 20 mu m particles are deposited in the upper lung airways (G0-G5) and no particles pass through G7. Particles can go into deeper airways as their diameter decreases. When the particle size is decreased to 5 mu m, over 48% of particles can pass through G14 and enter the deeper lung airways. An increase in age causes more particles to deposit in the upper airway and fewer particles to enter the deeper airways. (C) 2021 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.