AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Explaining the U-shaped Pattern in the Viability of Airborne Viruses vs. Relative Humidity
KAISEN LIN, Linsey Marr, Virginia Tech
Abstract Number: 101 Working Group: Bioaerosols
Abstract Infectious diseases, such as lower respiratory infections and tuberculosis, are among the leading causes of death globally. Successful transmission of infectious disease requires infectious agents to remain viable during their transport from infected individuals to susceptible individuals. Thus, understanding the viability of infectious agents under different environmental conditions is critical for controlling infectious disease transmission. Our previous studies observed a U-shaped pattern in viral viability against relative humidity (RH). Specifically, the viability of viruses was higher at RH below 43% and at 100% RH, whereas it was lower at intermediate RHs. A similar pattern has been reported before but surprisingly has not been well explained yet. We hypothesized that the viability of viruses was governed by the dynamic change in solute concentrations in carrier droplets as they evaporate. In this study, we explored the evaporation of droplets at various RHs, aiming to understand the impact of RH on solute concentrations over time. We found that solute concentrations remained high at intermediate RH for an extended time, causing lethal effects on viruses. At low RHs, droplets evaporated too fast to allow solute concentrations to remain high for extended periods, and at high RHs, droplets evaporated too slowly for solute concentrations to increase significantly. In both situations, viruses were able to sustain their viability. This finding explained the observed U-shaped pattern in viability of viruses against RH, and emphasized the importance of the droplet evaporation process on the viability of infectious agents.