September 25, 2020

Efficacy of masks and face coverings in controlling outward aerosol particle emission from expiratory activities

Category: Article Summary

Topic: Non-Pharmaceutical Interventions

Keywords (Tags): masks, non-pharm interventions

• Surgical masks and unvented KN95 respirators reduce outward particle emissions by 90% during speaking and 74% during coughing, compared to wearing no mask. These masks decreased the outward particle emission of a coughing superemitter who produced up to two orders more expiratory particles than average. Due to experimental confounding, the study was not able to directly determine the degree to which cotton masks blocked exhaled particles but the authors note that double-layer cotton masks reduced the emission of larger particles, indicating some reduction expiratory particle emission.

Asadi et al. (Sept 24, 2020). Efficacy of masks and face coverings in controlling outward aerosol particle emission from expiratory activities. Nature.
https://doi.org/10.1038/s41598-020-72798-7