The government’s Novel Coronavirus Response and Coordination Centre provided advice in a statement yesterday on how to reduce the risk of COVID-19 transmission in buildings.
According to the statement, COVID-19 is mainly spread by droplets from the nose and mouth between people in close contact and through spray from someone coughing or sneezing in a confined or semi-confined space for a long time, or through indirect contact with surfaces or objects.
The statement noted that examples of spray include tiny droplets produced when talking or coughing and polluted particles raised by a fan, which can be suspended in the air for a long time. The statement added that one can be infected after “prolonged exposure to a high concentration of droplets”.
The statement pointed out that based on previous experience, the “vast majority of cases occurred among close contacts”, mainly those living together, eating and drinking in the same place, and having activities within the same space without wearing a facemask.
There have also been cases found in the same building, the statement underlined, while there have also been occurrences where more cases were detected on the same floor in some buildings. The statement underlined, however, that there is “no significant evidence that these cases were infected via balconies or pipes”.
The statement provided the following measures for members of the public to follow: wearing a facemask when leaving one’s home or work even for short periods of time such as when throwing rubbish away, especially when a case is detected in the building; avoiding touching surfaces in the buildings’ communal areas such as lift buttons and handrails, with appropriate hygiene measures taken immediately after doing so and avoiding touching one’s eyes, nose or mouth before washing one’s hands; and not entering crowded lift without a facemask when taking a lift with others.
Other measures listed in the statement are pouring water down the drain daily to prevent the U-shaped pipe from drying up; and maintaining good indoor air ventilation. The statement stressed that fresh air should enter through doors and windows facing open areas rather than through ones facing other units; and if an air extraction device for the building’s shared exhaust pipe is used without a backflow prevention device, one should keep the air extraction device turned on to prevent air from other units from flowing back into one’s own unit.
Lastly, the statement said that when exhaust fans in small spaces such as kitchens and toilets are turned on and there are no ventilation grilles, the door and window not facing balconies should stay half-open to allow air circulation and “avoid negative pressure to the drain”.
