156 Evaluation of cough and sneeze aerosol distribution while maintaining social distance in a confined space

During the coronavirus disease 2019 (COVID-19) pandemic, many countries recommended social distances to prevent aerosol transmission. But in some cases, if there is insufficient ventilation condition especially in a stagnant air space, or other ventilation conditions, droplets from coughs or sneezes may have different potential infection impacts. In this study, a TSI Aerodynamic Particle Sizer® (APS™) 3321 spectrometer was used to measure the aerosol size distributions of coughs and sneezes from volunteer subjects. The APS detects particles in the 0.37 to 20 μm range, with high-resolution sizing from 0.5 to 20 μm aerodynamic diameter. And it was placed in the sitting breathing area (80 cm height) in front of the volunteers in a testing chamber (2.0*2.0*2.1 m³). The social distance was 6 feet. The APS was used to sample for 1 minute after each action and was continued to sample the self-preserving distribution for aerosol coagulation for 30 minutes. The results showed after continuous monitoring for 30 minutes, the sneezing droplet range of male and female was between 0.523 ~ 5.425 μm, and the coughing droplet was in 0.523 ~ 4.371 μm; the mode droplet size of sneezing was 17.154 μm (0.08 mg/m³) for male and was about 14.855 μm (0.11 mg/m³) for female. Moreover, the mode droplet size of coughing for male was 10.366 μm (0.06 mg/m³), and 11.14 μm (0.02 mg/m³) for female, the droplet of a sneeze was larger and heavier than that of a cough while maintaining social distance after 30 minutes’ suspension and coagulation.