Short-range bioaerosol deposition and inhalation of cough droplets and performance of personalized ventilation

A short distance between infected persons and exposed persons can probably result in a high risk of respiratory infection. This work experimentally investigated the short-range bioaerosol deposition and inhalation by a healthy person (HP) and the effect of a personalized ventilation (PV) on the HP, who was exposed to cough droplets from an infected person (IP) over a short distance between 0.5 m and 1.2 m. Benign E. coli was employed to represent the pathogen from the respiratory droplets. The microorganism deposition on different locations of the HP’s body (shoulder, chest and body back) and face (forehead, cheek, and chin) as well as inhalation were characterized by a cultivation method. It was found that the inhalation and deposition of vital pathogens on the face and body surface of the HP increased as the distance between the HP and the IP decreased. PV has been showed to reduce exposure by inhalation, while this is the first time to demonstrate that PV can also significantly reduce the number deposition. By optimizing the velocity of PV flow with respect to the distance, the bioaerosol deposited on the face and body and inhaled could be reduced by a maximum of 98%, 85% and 100%, respectively. For short-range disease transmission, physical barriers, e.g., mask and partition, are the conventional and believed to be the only intervention measures. The current results indicate that PV can be a potential method for infection control in the area of disease transmission in close contact situations.