Mask : General use and its protection against transmission of viral diseases (COVID-19)

Mask back then were mostly used by the health professionals and health care workers especially in the operating room during surgeries and operations and are also commonly used while normally examining the patients.

• Generally masks are used to prevent airborne transmission that’s why  nowadays people are more concerned in wearing mask in their daily lives because of the outbreak caused by Covid-19, a viral disease which is highly transmitted through the droplets and aerosols and the infected person has a high chance of transmitting it to a healthy person.
• Therefore, people are compelled to wear mask to make sure not to infect and not to be infected by a this illness.
• Different types of mask are commonly sold in drug stores and common shops, differing from variable price ranges  and depending upon the level of fluid resistant and protection.

Types of mask:

1. Cloth masks
2. Surgical masks
3. N95 Respirators

Cloth masks

• Cloth masks are simple and can be easily made at home with any variety of fabrics. Cotton is usually recommended as it does not causes rashes and blisters while wearing during summer heat.
• A cloth mask consists of multiple layer of fabrics. Thicker the fabric layer, greater will be the barrier for the dust to enter inside.
• Cloth masks cannot prevent from germ particles but can be washed and reuse for further use.

Surgical Masks

• Surgical masks are designed in such a way that the bacterial and viral particles cannot be filtered out from the pores of non-woven fabric which is a plastic like polypropylene and are fluid resistant and helps in preventing the spread of infections.
• These mask helps in blocking large droplets of particles to other person especially while talking, coughing, singing and sneezing but it does not block minute particles and fails in providing complete protection from contaminants.
• They are easily disposable and can only be used once at a time.

Surgical masks are differentiated into four levels which are ASTM certified:

• Surgical respirators are used by frontline health workers as it is highly protective from the microbes present in the droplets and aerosols.
• N95 masks are fitted on a face tightly without allowing the outside air to enter into nose and mouth.
• They are made from synthetic plastic fibers called polypropylene which provides an electrostatic charge that makes the filter more constructive.
• These types of masks are also easily disposable and can be used only once.
• These masks are certified by CDC and they can filter 95% of the airborne diseases hence, the name given N95.

Can mask really save us from viral transmission, COVID-19?

• In 2005, in United States, public wore masks in order to reduce the transmission of Swine flu until the production of vaccine which was very effective where the transmission rate decreased instantly which made people aware.
• Now, recently, the pandemic of Covid-19 has also made people to use mask to protect themselves from these viral particles as it is also an airborne disease where one symptomatic or asymptomatic infectious person can transmit the microbes in the form of droplets and splashes to a healthy person unknowingly.
• Many experts and researchers have stated that wearing a mask lessens a risk of getting infections as it blocks the germ from getting in and even if it escapes the barrier, then only minimum number of particles crosses and cause only mild type of infection not the severe one.

Experiment on how a mask decreases the rate of viral transmission

• Researchers have conducted several experiments on how effective is wearing a mask especially in a viral pandemic transmission.
• Viruses need living hosts to survive and are much smaller in size than other microbes whose size ranges from 0.1-100µm. With its minute size, it can easily escape through droplets and aerosols to other person.
• The pore size of masks that can be easily purchased have filter size of about 0.3-10 micron which can provide barrier to microbes greater than 0.3 but fails to provide protection from minute particles less than 0.3µm.
• So in order to test how masks save us from viral transmission, microbiologists performed an experiment using bacterial culture medium with a regular agar plate where they coughed, sneezed, talked and sang near two agar plates with and without wearing a mask.

• After 24 hour of incubation, they reported that bacterial colonies were grown on a whole surface where they used no mask but only a single colony were observed in a plate with a mask on.
• As we all know that viruses cannot be cultured and needs a specialized procedure, we have to take bacteria as a substitute to demonstrate how viral particles are transmitted through a vector where large droplets serves as one.

Therefore, wearing a mask with covering a face is like wearing a seat belt while driving.

Learn more

References:

1. https://www.fda.gov/medical-devices/coronavirus-covid-19-and-medical-devices/face-masks-and-surgical-masks-covid-19-manufacturing-purchasing-importing-and-donating-masks-during.
2. https://www.thomasnet.com/articles/other/how-surgical-masks-are-made/
3. https://www.fda.gov/medical-devices/personal-protective-equipment-infection-control/n95-respirators-surgical-masks-and-face-masks
4. https://www.umms.org/coronavirus/what-to-know/masks/mask-types
5. https://www.healthline.com/health/cold-flu/mask#recommendations
6. https://www.nytimes.com/2020/07/27/health/coronavirus-mask-protection.html
7. https://www.cbs8.com/article/news/health/coronavirus/how-effective-is-wearing-a-mask/509-56a8df25-14c0-46f9-8d39-94bb3a335b1b