3D modeling of the airflow and aerosol deposition in the existence of dust

Annually, more than two million deaths are caused due to the exposure of air pollution which cause damage to the lungs and the respiratory system. Topography, light-textured topsoil, drought, and desert climate make Saudi Arabia vulnerable to sand storms and dust. The study aims to examine the deposition of dust particles in the human airway and its relationship to asthma and investigate the possibility that the dust deposition would be changed with different particle size diameters. An idealized upper respiratory tract 3D model was constructed with computer-aided design software. Later a computational simulation was performed using computational fluid dynamics with 3 different sizes (0.03, 2, and 9 microns) of the dust particles to find out the change in airflow velocity and pressure. Our findings revealed that small size particles will travel more with less inertia, whereas bigger size particles will travel less but with higher inertia at airflow rates of 30 L/min. It was found that dust deposition in the respiratory system determines the probability of inhalation and total deposition in the alveoli greatly varies with particle diameter size. An idealized URT model replicate patient-specific URT geometry which helped in finding real-time airflow velocity and pressure of dust particles. Particles with smaller diameter are capable of 100% deposition and inhalation rate at the alveoli, whereas particles with bigger diameter tend to deposit less and with lower inhalation rates at the alveoli.