Masks and More Masks

There is some evidence that professionally fitted N95 respirators worn by trained professionals for short periods can reduce the transmission of respiratory illness. There is no evidence that cloth, surgical or N95 masks worn by members of the general public, let alone children, have any significant benefit.

More information is here and here. Many studies are reviewed here and here, as well as here and here. This excellent new study from Spain shows the ineffectiveness of masks in school.

Masks also carry risk of harm, especially to children. Some possible impacts are discussed here and here.

More information has come out recently about particles from masks being found in people's lungs, specifically microplastics and titanium dioxide.  A recent study of 35 countries, here, and summarized in a news article here, finds that countries with higher mask compliance did not perform better against Covid and in fact had slightly higher overall mortality.