Reduction of exposure to simulated respiratory aerosols using ventilation, physical distancing, and universal masking

The association between human respiratory disease transmission by respiratory droplets and aerosols is well established for several known pathogens.1 Given that the average individual spends > 90% of their day indoors, there has been intense focus on factors associated with indoor transmission. To minimize exposure risks, the Centers for Disease Control and Prevention (CDC) recommends behavioral and personal protective equipment mitigation strategies to limit COVID-19 transmission, including wearing masks, maintaining physical distances of ≥ 1.8 m, and avoiding crowded indoor and outdoor spaces. As such, the current investigation examines the combined effect of physical distancing, universal masking, and ventilation on exposure to airborne particles generated during breathing and coughing within a controlled indoor environment. The results of this investigation quantitatively examine the contribution of the matrix of controls employed and provides guidance on respiratory disease mitigation strategies within the indoor environment.