The presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in fecal material has raised the possibility of viral transmission via a fecal–oral route. This study investigated wheth... Visual Fecal Aerosol Transmission of SARS-CoV-2 The presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in fecal material has raised the possibility of viral transmiss... Background: The role of fecal aerosols in the transmission of severe acute respiratory syndrome coronavirus 2 has been suspected. Objective: To investigate the temporal and spatial distributions of...

The human cough is a significant vector in the transmission of respiratory diseases in indoor environments. The cough flow is characterized as a two-stage jet; specifically, the starting jet (when the cough starts and flow is released) and interrupted jet (after the source supply is terminated). During the starting-jet stage, the flow rate is a function of time; three temporal profiles of the exit velocity (pulsation, sinusoidal and real-cough) were investigated in this study, and our results showed that the cough flow’s maximum penetration distance was in the range of a 50.6–85.5 opening diameter (D) under our experimental conditions. The real-cough and sinusoidal cases exhibited greater penetration ability than the pulsation cases under the same characteristic Reynolds number (Re_c) and normalized cough expired volume (Q/AD, with Q as the cough expired volume and A as the opening area). However, the effects of Re_c and Q/AD on the maximum penetration distances proved to be more significant; larger values of Re_c and Q/AD reflected cough flows with greater penetration distances. A protocol was developed to scale the particle experiments between the prototype in air, and the model in water. The water tank experiments revealed that although medium and large particles deposit readily, their maximum spread distance is similar to that of small particles. Moreover, the leading vortex plays an important role in enhancing particle transport.