Exploring the Effects of Saliva Modifiers on Airborne Transmission: Computational Insights into Droplet Behavior during Sneezing

The purpose of this investigation is to explore new factors relevant to airborne transmission by examining how saliva modifiers affect the size distribution of droplets released during speaking, sneezing, and coughing. To accomplish this, computational fluid dynamics models are utilized to simulate an adult human sneezing in a ventilated room. Various foods, including Corn Starch, Xanthum Gum, Lozenges, and Zingiber, are examined computationally as potential saliva modifiers, with their impact on droplet size, viscosity, and flow rate analyzed and compared to a base case scenario without any saliva modification. This study finds that larger droplets alone are not sufficient to facilitate the settling of released droplets, as they undergo multiple processes of breakdown and coalescence. Droplets with higher viscosities are more likely to resist breakdown, leading to faster-settling rates. For example, the use of Xanthum Gum increases droplet size and liquid viscosity, resulting in larger droplets that tend to settle quicker. In contrast, the use of corn starch increases droplet size while keeping saliva viscosity constant. Other saliva modifiers, such as lozenge, increase sneezing flow rate by 113% and droplet size by 50%, leading to a slower settling rate. However, Zingiber reduces droplet size by 50% and flow rate by 80%, decreasing exposure levels during sneezing. The other aspect of the research developed an analytical equation, enabling to generate results without the need for time-consuming numerical simulations. Overall, this study offers valuable insight into the potential impact of saliva modifiers on airborne transmission and emphasizes the importance of considering these factors in future prevention strategies.