AUGUST 23 — Prior to Covid-19, we spend approximately 90 per cent of our time in enclosed spaces, be it inside or outside our homes. In the time of Covid-19, more individuals are staying home for prolonged periods, many due to the movement control order, and for some due to personal choice as a social distancing measure.

Initially, it was thought that SARS-CoV-2  —  the virus that causes Covid-19  —  was primarily transmitted through droplets generated when an infected person coughs or sneezes. More than thirteen months after the World Health Organisation declared the pandemic, the agency has formally recognised that SARS-CoV-2 is airborne.

How does indoor air quality affect Covid-19 transmission? The risk of getting Covid-19 is higher in crowded and inadequately ventilated spaces where infected people spend long periods of time together in close proximity. These environments are where the virus appears to spread by respiratory droplets or aerosols more efficiently, so taking precautions is even more important.

What makes indoor spaces so dangerous is that exhaled virus can accumulate and infect people who do not have direct contact with an infected person. A prime example happened earlier in the year where Covid-19 cases emerged in gyms and fitness centres around Klang Valley, despite physical distancing of attendees and capacity limits on fitness classes, forcing temporary closures on these establishments for sanitisation and quarantine for staff who came into close contact with positive cases.

The risk of getting Covid-19 is higher in crowded and inadequately ventilated spaces where infected people spend long periods of time together in close proximity. — Reuters pic

Ventilation and maintaining good indoor air quality, when used along with other best practices recommended by the Ministry of Health and others, can be part of a plan to protect people indoors. The Department of Occupational Safety and Health has recently developed a ventilation and indoor air quality guide that can be used during the Covid-19 pandemic to reduce the airborne transmission of the virus. The public may consider adopting this general advice, which can be applied to all homes: