Influence of Bifurcation Morphology on Exercise-Induced PAH Deposition in the Lungs: A Computational Modeling...

This study examines the influence of lung geometry, physical activity intensity, and aerosol concentration on the deposition efficiencies (DEs) of particulate matter with surface-bound polycyclic aromatic hydrocarbons (PM-_PAHs) in human lung generations 3-6. Two-phase flows were effected in ANSYS 2020R2 platform using planar and orthogonal lung geometries, with two levels of physical activities, 4 metabolic equivalents (4 METs), and 8 METs. Aerosol concentrations of 0.95 μg‧m^-3, 1.57 μg‧m^-3, and 2.04 μg‧m^-3 represent rural, urban, and industrial areas, respectively. Relative differences in DEs for 1 μm, 3.2 μm, and 5.6 μm exhibit variations between the two geometries with ranges of 0%-84.4% for 4 METs and 1.2%-50.7% for 8 METs. The first carina region was the most significant hotspot for the 5.6 μm particles. On the other hand, the 1 μm and 3.2 μm aerosols infiltrated and deposited evenly at the lower sections of the lungs. Regarding PM-_PAHs doses, spatial variations indicate an industrial > urban > rural hierarchy. This investigation suggests that individuals in industrial and urban locations should manage the intensity of their outdoor activities to minimize exposure to PM-_PAHs. These findings are instrumental for public health interventions aimed at reducing exposure to PM-_PAHs and preventing associated health problems.