Date: May 26, 2021

Source: Institute for Environment and Climate Research

Science has released a research paper titled Face masks effectively limit the probability of SARS-CoV-2 transmission. The paper is co-authored by Prof. Su Hang and Chen Yafang from the Max Planck Institute for Chemistry in Germany, and Prof. Ma Nan from JNU. The paper sheds light on the mechanism of using masks to reduce the basic reproductive number (R0) of the Covid-19 virus, with aerosol and epidemiological theories. It also explains why the masks' effects differ in environments with varied virus concentrations.  

As a common measure to reduce the spread of viruses through the air, wearing masks has been found to decrease the virus excreted by infectors and inhaled by healthy people. Therefore, it is also one of the main measures to contain the global pandemic. There is still much debate about whether it makes sense to wear a mask. Since 30 to 70 percent of particulate matter can pass through even a surgical mask, a lot of aerosol particles can still be expelled or inhaled. Some argue that common masks or even medical masks may not effectively protect people from the novel coronavirus. In addition, some random clinical trials on the utility of masks also failed to indicate a clear conclusion. In contrast, statistics show that areas with high mask-wearing rates do more effectively contain COVID-19.

This study, combining aerosol and epidemiological theories, gives a scientific explanation for the current debate on masks' effectiveness against the novel coronavirus, which is of great significance for the epidemic prevention and control.

Paper DOI: 10.1126/science.abg6296

Link to paper:  

https://science.sciencemag.org/content/early/2021/05/19/science.abg6296