Abstract View
Viable Virus Transport in Ventilation Airflow
TATIANA BAIG, Maria King, Texas A&M University
Abstract Number: 228
Working Group: Infectious Aerosols in the Age of COVID-19
Abstract
Currently little is known on how SARS-CoV-2 spreads indoors and its infectability. The objective of this study is to gain more knowledge on the effect of environmental factors on the spread and infectivity of virus aerosols in the built environment. Understanding how the virus transmits indoors would allow for early detection of viral particles in room sized spaces. Bovine coronavirus (BCoV), was used as virus simulant in laboratory experiments conducted in a controlled humidity chamber. An air-jet nebulizer was used to disseminate known numbers of BCoV particles. Particle tracking velocimetry, PTV, with shadowgraphy techniques was used to monitor the effect of environmental conditions (temperature and relative humidity) on the size distribution and velocity of the virus particles. After aerosolization, the surface in the cabinet was sampled at regular time intervals to assess the number of particles impacted. The samples were quantified using quantitative polymerase chain reaction (qPCR). The virus aerosols that remained suspended in the air were collected using the portable viable bioaerosol collector (VBAC) at 100 L/min with the MD8 reference sampler at 50 L/min and quantitated by qPCR. BCoV samples were tested before aerosolizing in the humidity chamber and again after the aerosol samples were collected using biolayer interferometry to determine the environmental effects on association and dissociation of the virus to surfaces. The study shows that impaction-based collection using gelatin filters results in virus aerosol numbers that are a magnitude higher compared to impingement-based sampling. Similarly, high numbers of virus aerosols were collected from the chamber surfaces. Kinetics studies with interferometry show a strong attachment of the coronavirus to hydrophobic surfaces, exhibiting increasing association at low temperatures and in the presence of hydrophobic compounds. PTV analysis of the aerosols shows that environmental parameters affect virus aerosolization and resuspension and could play an important role in COVID-19 transmission.