Staying safe indoors

OVER the past 18 months, we have been staying indoors for prolonged periods due to the implementation of the movement control order to curb the spread of Covid-19. Even before this, we were already spending almost 90% of our time in enclosed spaces be it at home, in the office or other places.

It was initially thought that SARS-CoV-2, the virus that causes Covid-19, was primarily transmitted through droplets generated by an infected person through breathing, coughing or sneezing. More than 13 months after the World Health Organisation declared Covid-19 a pandemic (March 11, 2020), it 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 people spend long periods of time in close proximity with an infected person.

The virus appears to spread by respiratory droplets or aerosols more efficiently in indoor environments, so taking precautions here is even more important.

What makes indoor spaces so dangerous is the accumulation of the exhaled virus, which can infect people even though they do not have direct contact with an infected person. A prime example happened earlier in the year when Covid-19 cases emerged in gyms and fitness centres around Klang Valley.

Despite maintaining physical distancing and observing the capacity limits on the premises, some of the patrons were infected, forcing temporary closure of the gyms for sanitisation and quarantine for staff who came into close contact with the positive cases.

Ventilation and maintaining good indoor air quality, when used with standard operating procedures recommended by the Health Ministry, can be part of measures to protect people indoors. The Department of Occupational Safety and Health 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 guide, which can be applied to all homes:

> Open windows to ventilate room spaces with clean outdoor air. Leave a small opening when air-conditioners are on. Opening windows remains key in curbing the spread of the virus, health experts say;

> Use electric fans to increase air movement and enhance thermal comfort;

> To improve ventilation, operate exhaust fans wherever available;

> If operating an air-conditioning system, set the temperature to between 23°C and 26°C;

> Maintain humidity between 40% and 70%;

> Ensure the water seal in the sanitary system is intact and rectify cracks, if any; and

> Create an isolation area for household members who are sick, infected or under surveillance.

Better indoor air quality has been proven to reduce the transmission of Covid-19. Maintaining good quality of air indoors will also reduce people’s risk of developing chronic respiratory illnesses, which in turn will help in the fight against future pandemics.

DR NUR NABILA ABD RAHIM

Doctor of Public Health candidate

and DR LIM YIN CHENG

Public Health Medicine specialist and lecturer

Faculty of Medicine

Universiti Malaya