“This unexpected finding raises an alarm that wearing masks with very low filtration efficiencies may lead to a higher chance of deposition of ambient aerosols and thus can do more harm than protection.”

Jinxiang XiXiuhua April Si et al. Effects of mask-wearing on the inhalability and deposition of airborne SARS-CoV-2 aerosols in human upper airway. Physics of Fluids 32. 15 December 2020. https://aip.scitation.org/doi/10.1063/5.0034580.