NEW DELHI: If an office does not have a mechanical ventilation system to bring in fresh air, then one needs to open all windows and use air-conditioning to a minimum, when that is happening — these are the new directives issued by Singapore, as it starts seeing a rise in Covid cases again.
With new studies suggesting Covid-19 is airborne, lack of ventilation may be leading to an upsurge in not only Covid-19 cases, but can spread black fungus too.
Government of India guidelines for both Covid-19 and mucormycosis state proper ventilation is required to prevent them from spreading indoors.
For black fungus, the guidelines say its spores can travel in an enclosed space, making it essential for hospitals with these cases to have adequate ventilation.
India’s latest guidelines for Covid-19, issued by the ministry of health and family welfare acknowledge the possibility of the virus remaining airborne and travelling up to 10 metres in distance.
“Current evidence suggests that the virus spreads mainly between people who are in close contact with each other, typically within one metre (short-range).
A person can be infected when aerosols or droplets containing the virus are inhaled or come directly in contact with the eyes, nose, or mouth.
The virus can also spread in poorly ventilated and/or crowded indoor settings, where people tend to spend longer periods of time in physical proximity.
This is because aerosols remain suspended in the air or may travel farther than one metre (long-range),” the revised protocol says.
Dr Priyanka Kulshreshtha, who is part of the Society for Indoor Environment (SIE), says even with a Covid-positive patient isolating at home, ventilation is extremely important in order to maintain a “negative pressure” in the room.
“Since temperatures are high at the moment and we live in a dry climate zone, the droplets evaporate quickly and the virus stays suspended longer in the air.
In order to ensure it does not stay there or infect others in the household, it is important to keep a window open in that particular room.
While using air-conditioning, the temperature should be maintained between 24 and 27 and a fan should be used alongside it, with the window slightly ajar,” explains Kulshreshtha, stating the negative pressure outside helps the air and particles to escape.
Arun Sharma, professor-director at the University College of Medical Sciences (UCMS) in Delhi, says for patients in isolation, cross-ventilation remains the key, while stating it was important to not use air-conditioning in a closed environment.
He says to prevent black fungus from spreading, sanitisation remains the key.
“Like any fungus, it will be present as a mould and for that, one needs to regularly disinfect and clean surfaces where the mould can be present or can grow.
In places where there are cases, it is important to not allow moisture to deposit.
Air-conditioning vents also have to be cleaned periodically,” said Sharma.
United States Environment Protection Agency (EPA) recently flagged the risk of airborne transmission, recommending increasing ventilation with outdoor air and air filtration as important components to fight the virus.
“Evidence now confirms that this virus can remain airborne for longer times and further distances than originally thought.
In addition to close contact with infected people and contaminated surfaces, spread of Covid-19 may also occur via airborne particles in indoor environments, in some circumstances beyond the 6ft range encouraged by some social distancing recommendations,” said EPA, stating the use of face masks, even indoors, is important.
Barun Aggarwal, CEO at BreatheEasy and a member of Indian Society of Heating, Refrigerating and Air Conditioning Engineers (ISHRAE), says guidelines issued by the society last year for indoor ventilation still applies for homes, offices and healthcare facilities.
“H-13 certified filters, be it in officers or at homes, can soak up Covid-19 particles and allow steady ventilation, however, if that is not available, outdoor air needs to be introduced as much as possible, be it through windows or vents,” says Aggarwal.
Gaurav Burman, APAC president at 75F, a company offering indoor solutions for buildings, says ISHRAE’s guidelines for buildings are comprehensive and need to be followed to keep Covid-19 at bay.