Fit Of The Mask: Explaining the kind of fit required, Dr. Vivek Nangia, Director and Head of Pulmonology at Fortis Hospital, Delhi, says, "It should be snuggly fitted over the nose, mouth and go right below the chin to give the right fit. If there are leaks around and air can seep through then it doesn't make any sense."
As and when the levels of air pollution rise, experts and doctors suggest wearing an air pollution mask while stepping out of the house. Here are five things to keep in mind while buying a mask.
Filter Size: Air pollution consists of both suspended particulate matter and gases. While a majority of the masks only filter particulate matter, some possess charcoal filter and are touted to filter out gases. While buying a mask, check particulate matter size a mask can filter that is PM2.5, and PM0.3. "It should preferably be as small the size as possible", tells Dr. Nangia.
Durability: Broadly there are two types of masks available in the market - single-use and washable masks. While single-use masks are disposable in nature typically last for six to eight hours, reusable masks can be washed and their filter can be changed. "We wear a mask for 15-20 minutes everyday and not for eight hours. So depending on your daily usage, you can use a disposable mask for seven to 10 times. After washing, the efficiency of the filter comes down by over 50 per cent and the integrity of the fiber is compromised, says Barun Aggarwal, founder of Breathe Easy Consultants and co-founder at NGO Care For Air.
Quality Check: Just like while buying groceries or medicines one checks the expiry date, while buying a mask, one needs to take a look at its certification. A mask should be certified by a government agency assuring its quality. Since in India, there are no government specifications to certify air pollution mask, one can opt for N95 and N99 masks prescribed quality of masks, as per the American guidelines. "In simpler terms, N95 designation mask means 95 per cent of PM will be prevented from going inside the body. N99 filters claim to prevent 99 per cent of the PM of different levels. The size of the particle matter filtered will vary, depending on the type of mask you buy", says Dr Nangia.
Usability: A mask has to be kept dry. If in case it gets moist or wet, it needs to be discarded.