Task is to Mask
by Dr. Jastin Samuel,
Waste Valorization Research Lab,
Lovely Professional University, Punjab, India
N95 Masks, Surgical masks, homemade cloth masks, and respirators have become indicators of protection during the COVID-19 pandemic. Do these mask provide protection? How much protection can these masks really offer? Can they be reused, and what are their limits?
How do novel coronavirus spread?
Any person who is infected with coronavirus (symptomatic/asymptomatic), when they cough, sneeze, and even talk, they emit droplet which are small drops of moisture from the upper respiratory system. These droplets have high chances of carrying viable viruses like the one that causes COVID 19.
Large droplets (>5 micrometers) doesn’t travel much through the air and so they settle quickly. That is why it’s recommended to stay 6 feet (social distancing) from other people. These droplet may settle on the surfaces near us which remains viable (ability to infect) for a longer time and so it is very important to clean the surfaces and wash the hands after touching a surface that could be contaminated with infectious virus.
Small droplets emitted from the mouth and nose travel much farther than 6 feet and may stay in the air for an hour or longer, depending on the ventilation in the room. People spending time together in close proximity may be exposed to these small droplets.
What are the types of Masks available for a common man in the market?
N95 respirators are made of special material that stops at least 95% of even the small droplets. They’re also manufactured to fit with a tight seal around the nose and mouth so air and viral particles can’t get around the side of the respirator.
Surgical masks are also made of special material, but they don’t provide a seal around the nose and mouth, meaning that smaller droplets may still be inhaled. Surgical masks are good, however, to protect the nose and mouth from larger droplets from coughs or sneezes, and for preventing infected people from spreading droplets.
Homemade Cloth Masks may remove some large droplets but will not remove small ones. They cannot provide a seal around the nose and mouth, and their effectiveness is unlikely to be improved by face shields. These masks lack the electrostatic charged filter fiber which is most significant part to filter virus. If surgical masks are not available, cloth masks worn by infected people may reduce the spread through the large droplets alone. But still the spread of Coronavirus through tiny droplets which can travel long distance and remain in air for long time cannot be stopped
Do people know the mechanism by which masks protect them from Virus?
These capture, or filtration, mechanisms of N95 and surgical masks are described as follows:
Inertial Impaction: With this mechanism, particles having too much inertia due to size or mass cannot follow the air-stream as it is diverted around a filter fiber. This mechanism is responsible for collecting larger particles.
Interception: As particles pass close to a filter fiber, they may be intercepted by the fiber. Again, this mechanism is responsible for collecting larger particles.
Diffusion: Small particles are constantly bombarded by air molecules, which causes them to deviate from the air-stream and come into contact with a filter fiber. This mechanism is responsible for collecting smaller particles.
Electrostatic attraction: Oppositely charged particles are attracted to a charged fiber. This collection mechanism does not favor a certain particle size.
Ignorance about the mechanism of filtration mechanism of masks has led to several indigenous masks made by industries, individuals using cloths, single/double layer PPE material, thick colorful masks etc. Some people even claim that these masks would stop the droplets. But, these masks can stop less than 50% of moisture from a person’s nose and mouth. So, there is more than 50% chance of another person being infected.
Also, many people wear the mask for mouth alone. This is wrong as droplets from nose can spread the virus from one person to another
Some people wash the mask and reuse them. The surgical and N95 masks are the only masks that can successfully filter the virus compared to all other masks. The surgical mask is for single use only. Reusing the mask with/without washing is equal to not wearing the mask. While the availability of N95 respirator supplies can be extended if we reuse them until they are visibly soiled or structurally damaged.
Each mask or respirator should be stored in a separate breathable paper bag at room temperature between uses. Never touch the outer layer of the mask. Clean the hands with sanitizer before and after touching the mask. For breath easy, make sure that the mask has an exhale valve.
The Government should set norms for the masks manufacturing and selling and make sure that the ineffective masks like cloths, single/double layer PPE material, thick colorful masks don’t reach people as anyone wearing a mask considers himself/herself safe and confidently goes out in public. In such case a person wearing an ineffective mask becomes the major reason for rapid spread in the cities.
Our team has developed Oxigeno, a biodegradable respirator mask combining three replaceable, purifying filters. Not just that, the respirator even produces oxygen! How? One of the filters is algae-based, which absorbs the carbon dioxide and produces oxygen. For more info please read in the following link.