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 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.