Insufficient Ventilation raises COVID-19 Risk

A building environment specialist said people should avoid social gatherings in an indoor environment where sufficient ventilation is not provided as a study has shown that even people sitting at a distance were infected by coronavirus in such places.

Professor Yuguo Li from University of Hong Kong's department of mechanical engineering has studied clusters of Covid-19 infections that happened at a restaurant in Guangzhou and two buses in Hunan, as well as the Diamond Princess cruise ship in Japan.

"An indoor venue for heavy activities needs a higher ventilation rate than those for normal activities. Avoid

social gatherings in an indoor environment where sufficient ventilation is not provided," he said.

Speaking at an online seminar, Li said poor ventilation could facilitate the transmission of the virus, and advised against going to poorly-ventilated restaurants amid the coronavirus outbreak. Takeaways and avoiding insufficiently-ventilated restaurants might be a good idea, he said.

The study Li was involved in looked at the Guangzhou restaurant case that ocurred on January 24 that saw a cluster of nine people from three different families test positive for the coronavirus even though the groups were sitting far away from each other.

The Hunan buses case on January 22 saw an "index patient" take two buses and infect 10 other people. Li said in the Guangzhou and Hunan cases, there was evidence that airborne transmission of the virus was the cause as those infected were sitting at a distance of more than two metres apart and had no close contact with each other.

"I think the owners can also do or try their best to improve ventilation," he said.

"The issue is restaurants are different, some of them have a better location, the better kind of mechanism for providing good sufficient ventilation."

Source: rthk.hk and hku.hk