Face masks play crucial role, according to a new COVID research confirms

An international research team from universities including Chalmers University of Technology, Sweden, the University of Padua and the University of Udine in Italy, and the University of Vienna, Austria…This all has developed a new theoretical model for better access to the risk of spreading viruses such as Covid-19—with or without a face mask. The result has shown us how the standard 'safe' distance of two meters does not always apply but varies greatly depending on a range of environmental factors, and that face masks can indeed play a crucial role.

The current recommendations around the transmission of respiratory infectious diseases are often based on the diagram which was developed by American scientist William Firth Wells in 1934. This model is very simplified and it also does not account for the true complexity of transmission. In the study “Modeling the direct Virus exposure risk associated with respiratory events”, researchers have developed a more advanced model which shows it is possible to more effectively calculate the direct risk of spreading  Covid infection by including several factors such as interpersonal distance, temperature, humidity levels and a load of viral. They are also used to manage or to demonstrate how these risks change with and without a face mask.

According to studies and research, they took example, a person talking without a face mask can spread infected droplets one meter away. Should the same person cough, the drops can be spread up to three meters and if the person sneezes, the spread distance can be up to seven meters. But using a face mask decreases the risk of spreading the infection. Risk of infection can be reduced by using a surgical mask or FFP2 mask that it is practically negligible even if you're only standing one meter away from an infected person," explains Gaetano Sardina, Associate Professor of Fluid Mechanics at the Department of Mechanics and Maritime Sciences at Chalmers University of Technology, who is one of the researchers behind the study.

In a study published in the Journal of Royal Society Interface, researchers tested the new model using data from recent numerical experiments on droplet emissions. This allowed them to consider several factors and quantify the risk of infection, with and without a face mask.

Size a factor in droplet behavior:

• Viruses, such as SARS-COV-2, are spread from an infected individual to other susceptible individuals through virus-filled droplets that are released when talking, coughing, or sneezing.
• These droplets are emitted from the salivary glands and are sprayed out through the exhaled air. Once out of the mouth, these drops can either evaporate, settle or remain floating.
• Larger and heavier droplets tend to fall in a ballistic motion before evaporating, while smaller droplets behave like aerosols that spray and remain airborne.
• The results show that a surgical face mask and, to an even greater extent, an FFP2 mask provide excellent protection that significantly reduces the risk of infection.
• Provided that the face mask is worn correctly, the risk of infection is negligible even at distances as short as one meter, regardless of environmental conditions and if the person is talking, coughing, or sneezing.

Next step …… a study on the airborne spread:

The research team is trying to work on a new study that aims to explore the airborne spread of the diseases. "The published study addresses direct droplet transmission of Covid -- another important transmission path is the indirect and airborne route in poorly ventilated rooms. We are currently working on this aspect and our preliminary results show the effectiveness of face masks in also preventing the airborne spread of the disease," says Gaetano Sardina.

The international study was led by the University of Padua, Italy, and conducted in collaboration with the Chalmers University of Technology, the University of Udine, Italy, and the University of Vienna, Austria. The scientific article was written by Jietuo Wang, Federico Dalla Barba, Alessio Rocco, Gaetano Sardina, Alfredo Soldati, and Francesco Picano.