As PM2.5 and PM10 levels continue to rise several times above the safe level in Indian cities and towns, people have started using masks of various kinds to protect themselves from poor air quality. Cyclists, pedestrians, traffic cops and even metro train commuters have graduated to masks from scarves and handkerchiefs in the hope that these devices will guard their lungs. But do masks really work?
The primary function of masks is to filter out certain particles from the air. For effective protection, it is important to wear a well-fitting mask of the correct size, which covers the nose, mouth and chin completely without leaving any gaps.
But masks don’t block everything toxic in the air. They may protect the wearer against particulate matter but are ineffective against nitrates, sulphur dioxide, carbon monoxide, lead and other gaseous pollutants. Different pollutants cause different reactions in the human body, and respiratory diseases are only one of the many ailments.
Masks of greater complexity and effectiveness are available (See ‘Masks: Do they really work?’), but even these are stop-gap solutions. N95 masks cost more than Rs 50 and a single mask can be used for only two to three days. Even the more expensive N99 masks last for no more than four to six months.
In many cases, people have been known to use an N95 or an N99 over and over again. It can be safely reused only till the permissible limit. Once the mask loses its shape and develops leakages, it fails to serve its purpose. Even if it seems to be in perfect shape, the filters in the material itself may reach their filtering capacity over time, and reusing it only means one is breathing in the particulate matter stuck in the filters.
N95 and N99 masks are out of reach for those most vulnerable to the effects of air pollution—cyclists, hawkers, shopkeepers, commuters and drivers of public transport, traffic and general police—and a big expense even for those who can afford them.
Medical experts say a mildly wet handkerchief tied over the nose and mouth can simulate the effects of a mask. However, the handkerchief must be clean, and there must not be any leakages.
Masks were originally intended to safeguard industrial and health workers against occupational hazards, and can by no means be recommended as a medium- or long-term solution to air pollution. The bigger and more serious problem is the uncontrolled or unregulated rise in vehicular emissions, smoke from open burning and generator sets, firecrackers and industries. Unless we find solutions to these core problems, even face masks will fail to protect us some years from now.