Development of a Bioaerosol Experimental System for Virus Stability Measurement

Abstract

Respiratory infections, such as SARS, MERS, and COVID-19, have highlighted the importance of studying the transmission mechanism in indoor environments. Virus stability affected by temperature, humidity or particle size has remained inadequately investigated. A bioaerosol experiment system is developed in this study for virus stability measurement. Virus-laden droplets are generated by a Collison nebulizer, and afterwards enter a mixing chamber, where is filled with conditioned air. After complete evaporation, droplet nuclei go through an impactor, and only those smaller than the cut-off size (1μm, 2.5μm or 10μm) can finally enter Goldberg Drum to suspend for a designed period for later sampling and stability measurement. Temperature (20℃-40℃) and relative humidity (30%-80%) can be well controlled throughout the experiment. According to the virus inactivation mechanism, the sampling process is divided into the initial stage involving droplet evaporation and the subsequent aerosol suspension stage. Decay coefficients obtained by this method can be used for evaluation of virus exposure risks in indoor environments and for the development of efficient engineering control strategies.