Aerosol Dynamics on Inhalation at High Relative Humidity

点击翻译按钮获取中文摘要

Respiratory droplets are responsible for transmission of diseases such as COVID-19. The physicochemical dynamics of respiratory droplets are not well understood. The representativeness of surrogates for exhaled aerosol currently used for laboratory studies remains debated. In this study, two complementary instruments are used to measure the microphysical dynamics of respiratory surrogate solutions and the temporal evolution of droplet pH. Results show that within the range of ambient relative humidity values, uncertainty in viral survival is dependent upon the complex phase change behaviour of droplets, which in turn is dependent upon droplet composition. Exhaled aerosol experience a shift in pH, from neutral towards alkaline within a millisecond timescale, which is responsible for the infectivity loss of the virus in the aerosol phase. Future experiments will be carried out under a more realistic CO2-regulated environment to better simulate the gas phase conditions experienced by respiratory droplets thus improving the understanding of airborne disease transmission.