@article{Chen2023, 
author = {Wenzhao Chen and Li Liu and Jian Hang and Yuguo Li},
title = {Predominance of inhalation route in short-range transmission of respiratory viruses: Investigation based on computational fluid dynamics},
year = {2023},
journal = {Building Simulation},
volume = {16},
number = {5},
pages = {765-780},
keywords = {airborne transmission, close contact, short-range inhalation, large droplet spray, computational fluid dynamics},
url = {https://www.sciopen.com/article/10.1007/s12273-022-0968-y},
doi = {10.1007/s12273-022-0968-y},
abstract = {During the coronavirus disease 2019 pandemic, short-range virus transmission has been observed to have a higher risk of causing infection than long-range virus transmission. However, the roles played by the inhalation and large droplet routes cannot be distinguished in practice. A recent analytical study revealed the predominance of short-range inhalation over the large droplet spray route as causes of respiratory infections. In the current study, short-range exposure was analyzed via computational fluid dynamics (CFD) simulations using a discrete phase model. Detailed facial membranes, including eyes, nostrils, and a mouth, were considered. In CFD simulations, there is no need for a spherical approximation of the human head for estimating deposition nor the "anisokinetic aerosol sampling" approximation for estimating inhalation in the analytical model. We considered two scenarios (with two spheres [Scenario 1] and two human manikins [Scenario 2]), source–target distances of 0.2 to 2 m, and droplet diameters of 3 to 1,500 μm. The overall CFD exposure results agree well with data previously obtained from a simple analytical model. The CFD results confirm the predominance of the short-range inhalation route beyond 0.2 m for expiratory droplets smaller than 50 μm during talking and coughing. A critical droplet size of 87.5 μm was found to differentiate droplet behaviors. The number of droplets deposited on the target head exceeded those exposed to facial membranes, which implies a risk of exposure through the immediate surface route over a short range.}
}