How microplastics are transported and deposited in realistic upper airways?

This article focuses on the computational analysis of microplastic transport and deposition within the human upper lung airways using a computational fluid dynamics-discrete phase model (CFD-DPM). It examines how microplastic particle size, shape (spherical, tetrahedral, cylindrical), and inhalation flow rates (7.5 and 30 liters per minute) influence airflow characteristics and deposition patterns in regions including the nasal cavity, mouth-throat, pharynx, and trachea. Key findings indicate that the nasal cavity exhibits the highest microplastic deposition, with lower flow rates leading to greater deposition efficiency due to longer particle residence times and enhanced effects of gravitational sedimentation and Brownian diffusion. The study highlights the impact of airway geometry on airflow velocity, pressure, turbulence, and particle behavior, providing foundational insights for assessing respiratory exposure risks to microplastics and informing future research on their health effects under varied physiological and environmental conditions.