“Although surgical mask media may be adequate to remove bacteria exhaled or expelled by health care workers, they may not be sufficient to remove the submicrometer-size aerosols containing pathogens to which these health care workers are potentially exposed.”
Chen CC, Willeke K. Aerosol penetration through surgical masks. Am J Infect Control. 1992 Aug;20(4):177-84. https://www.ajicjournal.org/article/S0196-6553(05)80143-9/pdf. PMID: 1524265.