Ever since health experts and agencies around the world started to stress the wearing of masks – or “face coverings” – as one of the best ways to restrict the spread of the novel coronavirus infection, the question has been asked: what kind of mask is the best?
While research remains ongoing, most experts agree that N95 respirators provide the best protection against Covid-19; however, these masks are meant mostly for specialised use, and are expensive and uncomfortable to wear for long.
Health authorities in many countries including India have recommended simple home-made face coverings made of cloth, preferably cotton, which can be tied or fastened over the nose and mouth.
However, with the monsoon having set in over some parts of India, and set to proceed northward and westward over the next few weeks, three-ply surgical masks present an advantage.
At a webinar hosted recently by Indian Scientists’ Response to CoViD-19 (ISRC), a platform of more than 500 Indian scientists, engineers, technologists, doctors, public health researchers, science communicators, journalists, and students, it was argued that it is best to use three-ply surgical masks during the monsoon.
Material scientist Dr Arnab Bhattacharya of the Tata Institute of Fundamental Research (TIFR), Mumbai, underlined that these masks have an exterior that does not get wet during the monsoon.
“Most of these masks have a hydrophobic exterior. You can check whether your mask has this hydrophobic layer by placing a drop of water on it, and if the mask is water resistant, the droplet will roll off,” Prof Bhattacharya said.
It is important to wear the mask correctly – the side of the mask that is lighter in colour is meant to be inside, while the darker side, which is hydrophobic, should be worn outside.
Since the inside is not water resistant, if the mask does get wet inside, it is best to change it, and to leave it to dry before you use it again. However, if the mask gets completely drenched, you should discard it, as the efficacy of all masks reduces considerably if they get wet.
As for essential service providers, wearing a face shield is an ideal and comfortable alternative. The essential service provider can wear a mask underneath the shield, which will remain dry due to the protection provided by the face shield.