New Delhi: It’s 8:30 in the morning, 22-year-old Siddhi (name changed) is all set to step out for work, but not without an air pollution mask. From one room to another, while Siddhi is running around the house, looking for her mask and trying to not get late to work, her father simply asks, ‘Why do you even have to wear a mask? Why can’t you cover your face with a scarf or handkerchief just like the majority of the people?’ ‘Because it has a filter which protects me from inhaling toxic particles’, replies Siddhi to which her father asks, ‘How do you know your mask is useful and performing its job well?’
A valid question and here is what experts have to say:
Air pollution comprises of three substances namely particulate matter (PM) which is categorised into different levels as PM 1, PM 2.5, PM 10, so on and so forth. Then we have toxic gases like sulphur dioxide, carbon monoxide, nitrogen oxide, ammonia and then we have heavy metals like lead. Both particulate matter which is the suspended matter in the air, and toxic gases have an altogether different impact on a human body.
No air pollution mask can filter any of the toxic gas, but you can protect yourself from PM and heavy metals which enters deep inside your body. For instance, PM 10 and above size gets filtered at the level of the nose because of the filter in our nose which does not allow the larger particles to go inside, says Dr. Vivek Nangia, Director and Head of Pulmonology at Fortis Hospital, Delhi.
While a particle size between 2.5 and 10 can enter into the deeper parts like lungs, one less than 2.5 can penetrate and rest inside the lungs and from there, through the blood stream, travel to different parts of the body. Particle size less than 1 micron can go directly into the blood stream of the body and cause damage.
The whole issue is that we don’t have much literature or scientific data to support the effectiveness of masks against air pollution but there are certain NIOSH (National Institute for Occupational Safety and Health) approved – N95 and N99 masks. NIOSH is an American based organisation which approves the mask for the use of people who are in an occupational exposure to dust, smoke, and fumes, says Dr Nangia.
N95 and N99 masks are able to prevent PM 2.5 and smaller particles from entering the body by almost 95 per cent and 99 per cent respectively.
Things to keep in mind about masks to tackle air pollution:
- Barun Aggarwal, founder of Breathe Easy Consultants and co-founder at NGO Care For Air, believes that pollution masks are great at creating awareness about the problem and aid in reducing short term impact of air pollution. However, wearing a pollution mask for a longer period of time like two to three hours straight can have side effects in terms of higher exposure to carbon dioxide (CO2).
- The fit of the mask is crucial else the whole purpose will be defeated. Explaining the kind of fit required, Dr Nangia says,
It should be snuggly fitted over the nose, mouth and going right below the chin to give it the right fit. If there are leaks around and air can seep through then it doesn’t make any sense.
- Along with this, the 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.
While buying, look out for the particle size your mask can filter. Also, a mask has to be kept dried. If in case it gets moist or wet, it needs to be discarded, says Dr Nangia.
- Broadly there are two types of masks available in the market – single-use and washable masks. While single-use masks that 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 if you are using a disposable mask, you can use it for seven to 10 times and then dispose of. As far as washable masks are concerned, there is nothing called as washable HEPA filter. After washing, the efficiency of the filter comes down by over 50 per cent and the integrity of the fiber is compromised, says Mr Aggarwal.
Remember, surgical masks do not come under single-use pollution masks. In fact, surgical masks are not meant to prevent an individual from inhaling particulate matter and gases.
- Majority of the masks available in the market target only particulate matter. While using one such mask people feel they are breathing safe air, but in reality, masks do not block the harmful gases that are also polluting the air and inhaling these do cause damage to the body. Some of the masks available in the market possess charcoal filter and are touted to filter out gases. Talking about the same, Mr Aggarwal says,
If you have charcoal filter, it will help reduce the amount of gases but in a mask, you cannot put enough charcoal with the right kind of gas absorption technology to remove all the harmful gases. It can remove gases by 20-40 per cent but not 100 per cent.
Air Pollution Masks: The Final Verdict
The most important thing to remember is that pollution masks offer protection only from particulate matter, but this shouldn’t stop anyone from using it. Dr Nangia says,
Whatever protection they are offering is at least some protection as compared to no protection at all. One shouldn’t consider them completely redundant, in fact, people who are prone to allergies, or have an underlying lung disease and are susceptible to having complications due to the air pollution, should use a mask.