Tech Talk – Unravelling the transmission of vertical outbreaks: Each drainage stack is an aerosol factory

More than 10 vertical outbreaks of COVID-19 have been observed in high-rise housing in Hong Kong. Together with the 2003 SARS Amoy Garden outbreak, these outbreaks suggest the roles of building drainage pipes in the transmission of infection, probably not limited to SARS and SARS-CoV-2. In collaboration with the Environmental Protection Department (EPD), we conducted field measurements in some of the infection venues and explore the transmission mechanisms. In this Tech talk, Professor Yuguo Li, Chair Professor of Building Environment, shall demonstrate how his proposed chimney effect explains most of these infections, how the drainage pipe was poorly ventilated, what one can do to protect our family, and what society can do to provide healthy housing.