Face masks are designed to trap the discharge of respiratory droplets from the nose or mouth of the person wearing it, to trap dust particles from entering into the mouth or nose, as well as to reduce the risk inhalation or spill of substances unto the face (nose or mouth region) that may cause infection or become harmful to the wearer. Face masks which are solely designed to provide protection against breathing in substances from the air which can be harmful to the body are called respirators. They are designed specially to filter out these harmful substances which can contaminate the body when inhaled. Examples of these types of masks are the N95 and the Face Filtering Particles (FFP) masks. These types of masks are not designed for use by the general public and thus indicating that the face masks commonly worn around do not offer this degree of protection.

In 2003 during the outbreak of Severe Acute Respiratory Syndrome disease (SARS) in Asian countries such as China, Hong Kong. Singapore etc, most people wore either medical or non-medical face masks as a means of providing protection against the spread of the disease. Following the outbreak of the New Corona Virus in Wuhan, China, in December 2019 which causes an infectious respiratory disease known as COVID-19. The World Health Organisation (WHO) recommended adoption of preventive measures.

In addition to this, it was adviced that medical face masks should be worn by people who have been infected by COVID-19 in order to avoid the spreading of respiratory droplets to others not infected. These droplets can be discharged from the body either through coughing or sneezing. On the other hand, it is also to be worn by healthcare workers and other people taking care of the infected people [1]. This recommendation is supported by evidence from studies that showed that the use of medical face masks helps to hinder the discharge of these droplets from the body as have been seen in infections such as tuberculosis and influenza [2]. This recommendation for the use of face masks is not a stand alone measure as it has to be accompanied by other recommended preventive measures such maintain good hand and respiratory hygiene, maintaining proper physical distancing from people coughing or sneezing, seeking medical help when signs and symptoms of the disease are experiences etc.

People who are not infected or taking care of an infected person are not advised to wear face masks. However, in some cases, not all infected people show signs of being infected with the disease. Based on this, WHO advices that only when there is high rate of infection within a given geographical area, should people wear face masks.

Various studies have reported that non-medical face masks are not able to filter out microorganisms from entering the body through the nose or mouth and they are less effective than medical face masks for protection against the spread of respiratory droplets. The ease of their production and reuse after washing seems to be the main benefit of using them especially if they are made from textiles [2].

The use of face masks is only one of the preventive measures recommended to curb the spread of COVID-19 from infected people to non-infected as it helps to trap the released respiratory droplets within the mask. Using non-medical face mask by non-infected people in the community would mainly be useful when it serves as a means to control the source of the spread of the disease especially if the number of people infected without showing symptoms of the disease is more than the known infected people showing the symptoms of the disease. In this case, the use is often recommended when going out to public places with many people E.g taking a public transport or going to the market. One can still use face masks and still get infected if not used properly and bearing in mind that the virus can also be transmitted through the eyes.

When contemplating on making your own face mask, purchasing one or wearing it, it is necessary that you take into consideration what purpose it would serve and how you should use them. The guidelines on how to use face masks have been carefully described by WHO and United States, Centre for Disease Control as well as the Nigeria Centre for Disease Control.

Smart Ikechukwu Mbagwu is a Nigerian scientist, educator and researcher currently based at the University of Fribourg, Switzerland. His current research focuses on understanding the mechanisms involved in the pathogenesis of cerebral malaria and immune response induced by malaria-infected red blood cells-derived extracellular vesicles. Smart is also a public health enthusiast and engages in science communication by organizing science outreach programs for schoolchildren and science teachers. He can  be reached @wrytesmart@gmail.com/@SmartMbagwu

The views expressed in this article are the author`s own -- and do not necessarily reflect the editorial views of African Science Literacy Network (ASLN).

References

1. KHUT QY.  advice-on-the-use-of-masks-2019-ncov.www.who.int. Retrieved 2020-04-15.

2. ECDC. Using face masks in the  community, https://www.ecdc.europa.eu/sites/default/files/documents/COVID-19-use-face-masks-community.pdf  (accessed 15 April 2020).