Source and trajectories of inhaled particles from a surrounding environment and its deposition in the respiratory airway.

ABSTRACT

The inhalation exposure to airborne particles is investigated using a newly developed computational model that integrates the human respiratory airway with a human mannequin and at an enclosed room environment. Three free-stream air flow velocities (0.05, 0.20, and 0.35 m s⁻¹) that are in the range of occupational environments are used. Particles are released from different upstream locations and their trajectories are shown, which revealed that the trajectory paths of 80 µm particles that are inhaled are the same from the three different upstream planes evaluated. Smaller particles, 1 and 10 µm, exhibited different inhalation paths when released from different upstream distances. The free-stream velocity also has an effect on the particle trajectory particularly for larger particles. The aspiration efficiency for an extended range of particle sizes was evaluated. Reverse particle tracking matches the deposition in the respiratory airway with its initial particle source location. This can allow better risk assessments, and dosimetry determination due to inhalation exposure to contaminant sources.