Indian doctors have urged the people not to panic regarding the possibility of coronavirus being airborne, as evidence is still being evaluated.
The issue has resurfaced, with the WHO acknowledging evidence of airborne spread of the virus after receiving an open letter from 239 doctors across 32 countries saying that their studies show coronavirus can linger in the air and infect people.
Dr Samiran Panda, Head of Epidemiology and Communicable Diseases, ICMR, says that precautionary measures like wearing a mask, maintaining social distancing, cleaning hands with alcohol-based sanitizer, washing hands with soap, avoiding touching eyes, nose and mouth will still have to be followed — whether the virus is airborne or not.
According to World Health Organization (WHO), people can catch COVID-19 from others who have the virus. The disease spreads primarily from person to person through small droplets from the nose or mouth, which come out when a person with COVID-19 coughs, sneezes, or speaks.
These droplets are relatively heavy, do not travel far and quickly sink to the ground. People can catch COVID-19 if they breathe in these droplets from an infected person. That’s why it is important to maintain social distance of at least one metre from others.
These droplets can land on objects and surfaces around the person such as tables, doorknobs and handrails. People can get infected if they first touch these objects or surfaces, and then touch their eyes, nose or mouth. That’s why it is important to wash hands regularly with soap and water or clean with alcohol-based sanitizer.
Dr Panda feels a number of factors have to be taken into account while considering the possibility that coronavirus could be airborne. There is a lot of physics and biology involved, he says.
Using physics, we can calculate the size and weight of the water droplet which carries the virus and see if it is small enough to be carried in air or large enough to fall on the ground.
As the virus cannot survive outside a cell and that too a living cell, the size and weight of the cellular element also has to be taken into account.
Other important factors, says Dr Panda, are air flow, speed of wind, humidity, temperature and other environmental conditions. The conditions must be conducive to the survival of the virus. If the temperature is very high, the virus will not survive. The size of the water droplet should also be large enough to take the cell and the virus inside it, and also small enough to be able to float in air.
The COVID-19 virus does not spread in air like dust or pollen grains, argues Panda. The virus harboured in a living cell has to have a water droplet to carry it forward. The mechanical structural and biological aspects have to be perfectly attuned to take the virus from one point to another.
Studies are still on, so Dr Panda has urged the people not to be scared unnecessarily and not to start wearing masks at home.
Dr Raj Mohan Panda, Additional Professor at Public Health Foundation of India, agrees with Dr Samiran Panda. “The results of studies on COVID-19 being airborne are still inconclusive. However, we are already doing whatever is necessary for preventing the spread of the virus if it is airborne, like social distancing and wearing mask when outside. Public need not panic,” he says.
Dr Digambar Behera, former Dean and Head of the Department Pulmonary Medicine Post Graduate Institute of Medical Education and Research, Chandigarh, says scientists and doctors should do further research and study on the findings, and go through all reference material provided by the 239 doctors in their letter.
Dr Behera, a Padma awardee, says usually the droplets travel through air, but being around 5 microns or more, they travel upto 2 metres and settle down on the ground. “But if we produce smaller water particles of size 2.5 microns or less, they will not travel in the air for some distance but float and remain suspended in air,” he explains.
According to Dr Behera, active coronavirus can survive upto two hours as has been shown in some studies done in hospitals and departmental stores.
“We can come to a firm conclusion only after the material and references forwarded by doctors has been reviewed critically. At the moment we are taking adequate measures by maintaining social distance and wearing masks, and need not panic. In case it is proved beyond doubt that COVID-19 virus is airborne, then additional precautionary measures can be taken up.”
If coronavirus does turn out to be airborne, then the need for powerful air filters, minimizing re-circulation of air and indoor masks and better quality masks for health care workers may be necessary to filter out even the smallest respiratory droplets.
Ultraviolet lights are also under consideration to kill the virus in the air.
