In China, you rarely see images of coronavirus reports, and in Japan or South Korea, where no one walks around with a mask. Peru has forced all citizens to wear them when they leave their homes. In Mexico, the obligation depends on the state, as in France, and its use begins to differ according to the city council. In Bogotá, the capital of Colombia, you cannot take public transport without using it. In the United States, the Centers for Disease Control and Prevention has suggested that everyone on the street cover their nose with a mask. In other countries, such as Spain, although authorities are beginning to prefer widespread use, authorities are still studying what to do.

Although the World Health Organization (WHO) reiterates that priority should be given to the use of masks among health professionals and infected populations or among people living with infected people rather than the general population, as this can cause “false safety” and can lead to the termination of measures that have been shown to be more effective (e.g. washing hands and staying away from others), new research shows that their use helps prevent infected people (including asymptomatic people) from infecting others. According to its author, its publication in the journal Nature Medicine may help resolve a debate that has been exacerbated by the health crisis caused by the Covid-19 coronavirus in recent weeks.

In laboratory experiments, coveralls can greatly reduce the amount of various airborne viruses produced by infected patients. The viruses were measured using the “Gesundheit II machine,” which collects breath samples and was developed by Don Milton, a professor of applied environmental health at the University of Maryland School of Medicine and lead author of the study.

Milton has brought these findings to the White House, and they followed up on the U.S. head of state’s speeches last week. The U.S. Centers for Disease Control and Prevention says the agency is reconsidering its frequent recommendation that masks are not a useful preventive measure outside of medical institutions.

This debate came as doctors in many countries around the world faced a shortage of masks. This is a problem that shocks society. However, even though small businesses and individuals continue to make images of their own donations, some retailers refuse to allow employees to wear them because they are afraid of sending negative signals to customers. In the United States, there are even cases of insults and personal attacks.

More research supports their use to prevent transmission of aerosols and coronaviruses

Another study recently published in the Journal of Medical Virology focused on Covid-19, which reported N95 (the filtering capacity is slightly higher than FFP2), medical masks and masks made of four-ply paper and single-ply paper. The double-layer fabric can block 99.98%, 97.14% and 95.15% of viruses, respectively.

Researchers in this study said in China, “The use of surgical masks has been supported by many studies, but has also been rejected by other studies, which may be due to an error in judgment. In this Asian country, the recommendation is medium. People at risk use coveralls (people who work in high-density areas such as hospitals or train stations or who live with quarantine personnel, as well as administrative, security, police and courier personnel, whose work is related to Covid-19).

For those at low risk of infection, disposable medical masks are recommended. For those at very low risk, authorities stated that citizens should not wear clothing or use non-medical masks (e.g., homemade masks made of fabric). With regard to the latter, the WHO believes that masks made of cotton can be easily infected with liquids and therefore may be a potential source of infection. This means that they can retain moisture and become contaminated.

Opinions on their use in different countries (even within countries) vary. In addition, evidence on the effectiveness of the mask is gradually being released, and the recommendation is likely to change. They are already doing this.