Limited, indirect evidence from lab studies suggests that homemade fabric masks may capture large respiratory droplets, but there is no evidence they impede the transmission of aerosols implicated in the spread of COVID-19, according to a paper published yesterday by the National Academy of Sciences, Engineering, and Medicine.
Mary Van Beusekom writes in CIDRAP that in the paper, the National Academies’ Standing Committee on Emerging Infectious Diseases and 21st Century Health Threats said that, because no studies have been done on the effectiveness of cloth masks in preventing transmission of coronavirus to others, it is impossible to assess their benefits, if any.