Science, crucial masks for asymptomatics

The masks are fundamental tools to prevent asymptomatics from spreading the coronavirus by air: it is no coincidence that the countries that have imposed its use on the entire population are those that have best contained the spread of the Covid epidemic- 19. This is indicated by an article published in Science by Kimberly A. Prather and Robert T. Schooley, of the University of California in San Diego, together with Chia C. Wang of Sun Yat-sen University in Taiwan.

Experts point out that the recommendations to keep your distance and wash your hands frequently to limit the infection are based on studies of the respiratory droplets conducted in the thirties, when there was still no technology to study the spread of aerosol. Recent research has shown that strong coughing and sneezing, in addition to generating droplets that spread over 6 meters, also emit even finer particles that form the aerosol and transport the virus even further. Furthermore, it has been estimated that speaking aloud for a minute, up to 100,000 viral particles can be emitted and remain suspended in the air.

This aerosol can accumulate in closed environments with little air exchange, penetrating deep into the lungs. Not being able to predict the movements of this aerosol it is difficult to define a distance that is of real safety: for this reason, according to the three experts, the masks are a fundamental physical barrier to be adopted. This is also demonstrated by the successes achieved in containing the contagion from countries such as Taiwan, Hong Kong, Singapore and South Korea, where the mask has been worn by everyone. Its use is particularly important in crowded places with poor ventilation, such as hospitals, planes and restaurants.