American scientists have conducted research to test the effectiveness of masks with valves and protective screens.
According to Gazeta.ru, the results of the experiment were published on the portal Physics of Fluids.
During the study, experts found that the droplets and aerosols that come out of the mouth when inhaled move freely along the border of the protective screen. Over time, they spread to the environment, although not in the previous concentration.
Thus, the ineffectiveness of these masks has been identified.
Earlier, scientists found that conventional surgical masks slow down the spread of respiratory irritants, including coronavirus.
Therefore, scientists have called for the use of ordinary medical masks.