Background: As common pathogens in the human respiratory tract, fungal-spore-related health risks have been challenging to evaluate properly. This paper presents numerical simulations of particle deposition of Aspergillus niger spores in human nasal cavities. Methods: 30 healthy adults (including 60 nasal chambers) who lived in northwest China were recruited to conduct a nasal cavity numerical simulation using computational fluid dynamics–discrete phase model (CFD-DPM). The deposition rate in each anatomic area and its influencing variables, such as body position and respiratory flow rate, were analyzed. Results: (1) Under a resting condition, only about 5.57% ± 1.51% Aspergillus niger spores were deposited in the nasal cavity, while most of them escaped from the nasopharynx, and 0.31% ± 0.20% spores entered the maxillary sinus; (2) under an exercising condition, spores deposited in the nasal cavity were about 2.09 times as many as that in the resting state; (3) in a lying position, the A. niger spores deposited evenly on the lateral wall of the nasal cavity and the sinus when compared with a standing position. However, the deposition rate in each anatomic area did not change significantly.
