Assessment of COVID-19 Infection Risks in an Office Building: Field Study Investigation in Shenzhen, China

The current cases and studies show that the aerosol propagation of COVID-19 is possible in the office buildings. The paper explored the ventilation level and monitoring methods for indoor infection risk in office buildings, improved the Wells-Riley equation and ventilation rate equation, providing the possibility of real-time monitoring of the transmission risk of COVID-19 in office buildings. Then, the main influencing factors of the exposure risk of SARS-CoV-2, including working density, dwell time, and fresh air volume per person, were field measured in three office areas and three conference rooms of an office building in Shenzhen, China. In addition, the field monitored carbon dioxide (CO2) data were used to estimate the possibility of COVID-19 infection in offices and conference rooms. The results show that the number of staff, ventilation rate, and office hours are all important factors affecting the infection risk of workers in the office building environment, but the existing literature rarely considers these three points at the same time. In addition, the paper adopted the method of assessing the infection risk from place to place, time to time, and person to person in the building environment, providing early warning for office buildings and helping to control the spread of airborne diseases. The results can be beneicial to understanding and taking necessary safety considerations against the infection risk in closed public or governmental environments.