Models of mask effectiveness:
Study 1, with 2000 nurses: https://jamanetwork.com/jou.../jama/article-abstract/2749214Study 2, with 485 nurses: https://jamanetwork.com/journals/jama/fullarticle/184819Study 3, parents taking care of sick children: https://www.ncbi.nlm.nih.gov/pubmed/19193267Some data on how effective masks are at filtering: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2662779/
Models of mask effectiveness:
Study 1, with 2000 nurses: https://jamanetwork.com/jou.../jama/article-abstract/2749214
Study 2, with 485 nurses: https://jamanetwork.com/journals/jama/fullarticle/184819
Study 3, parents taking care of sick children: https://www.ncbi.nlm.nih.gov/pubmed/19193267
Some data on how effective masks are at filtering: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2662779/