Safe drinking water, clean cooking gas, clean air, safe roads, and nonsmoking public places save more lives every year than all the hospitalbased care put together does. Similarly, condoms for safe sex have protected many people from sexually transmitted diseases including HIV. Helmets and seat belts saved many lives from road accidents.

According to estimates by the Centers for Disease Control and Prevention (CDC), WHO, and Global Health Partners, approximately 650,000 people die every year due to airborne influenza viruses. According to the Global Burden of Disease study published in Lancet (2018), in 2016, lower respiratory tract infections caused ~2.4 million deaths world-wide (~0.65 million in children under 5, and ~1.1 million deaths in adults over 70 years of age). Majority of these infections are airborne or transmitted through droplets. Millions more remain absent from work due to mild to moderate respiratory infections such as cough and colds.

With industrialization, urbanizationhas been growing rapidly across the world. Millions undertake daily travel in crowded public transport. Most modern offices are centrally air-conditioned becoming a potential path for the spread of airborne microbes. Daily shopping has shifted to large malls where thousands of people gather every day. Large public gatherings (religious, political, sports, entertainment etc.,) are a common feature. This increases the chances of contracting respiratory pathogens manifold compared to rural living.

Urbanization has also increased air pollution to dangerous levels in many cities and towns across the world. Air pollution is known to cause increased incidence of heart attacks, higher incidence or worsening of asthma, and acute exacerbation of chronic lung diseases. Other effects include tiredness, burning of eyes, irritation of nose and throat. Air pollution is one of the leading risk factors for deaths, estimated to account for five million excess deaths globally every year.

The use of face masks emerged to protect people exposed to high air pollution levels. The N95 and N99 types of face masks have evolved to filter toxic microparticles. The numbers denote filtering efficiency (For example, N95 has the capacity to filter up to 95 percent of airborne particles measuring less than five microns). In addition to filtering particulate matter, these masks are also capable of filtering microbes. Surgical masks filter macro particles (above five microns size) like bacteria and some of the large viruses like Corona viruses.

Respiratory diseases are the third leading cause of death and disability globally. Respiratory infections and air pollution contribute to significant proportion of these deaths and disabilities, smoking being the other major causative factor. Effective tobacco control, vaccinations in vulnerable people, and measures aimed at reducing air pollution have been proved to reduce the burden of respiratory diseases. In this context, use of face masks in high risk areas and by high risk individuals may have a large impact on respiratory disease burden by reducing transmission of airborne infections and offering protection from air pollution. Promotion of face mask use as a public health measure should come on to policy agenda of global health organizations and national ministries of health.

In summary, there is a compelling case for promoting the use of face mask as a public health policy measure with high impact on population health and improved productivity.