Face-masks save us from SARS-CoV-2 transmission

@inproceedings{Bagheri2021FacemasksSU,
  title={Face-masks save us from SARS-CoV-2 transmission},
  author={Gholamhossein Bagheri and Birte Thiede and Bardia Hejazi and Oliver Schlenczek and Eberhard Bodenschatz},
  year={2021}
}
We present results on the infection risk from SARS-CoV-2 under different scenarios based on measured particle size-dependent mask penetration, measured total inward leakage, measured human aerosol emission for sizes from 10nm to 1mm, and re-hydration on inhalation. Well-mixed room models significantly underestimate the risk of infection for short and direct exposure. To this end, we estimate the upper bound for infection risk with the susceptible in the infectious exhalation cloud or wearing… 

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References

SHOWING 1-10 OF 98 REFERENCES

Face masks effectively limit the probability of SARS-CoV-2 transmission

TLDR
It is convincingly shown that most people live in conditions in which the airborne virus load is low, and face masks are highly effective at preventing SARS-CoV-2 transmission because, in most environments, airborne virus abundance is limited.

Filtration efficiency of a large set of COVID-19 face masks commonly used in Brazil

TLDR
Masks always reduce droplets and aerosols emitted by COVID-19 symptomatic and asymptomatic persons, reducing SARS-CoV-2 contamination.

Visualizing the effectiveness of face masks in obstructing respiratory jets

TLDR
This work uses qualitative visualizations of emulated coughs and sneezes to examine how material- and design-choices impact the extent to which droplet-laden respiratory jets are blocked, and outlines the procedure for setting up simple visualization experiments using easily available materials.

Professional and Home-Made Face Masks Reduce Exposure to Respiratory Infections among the General Population

TLDR
Any type of general mask use is likely to decrease viral exposure and infection risk on a population level, in spite of imperfect fit and imperfect adherence, personal respirators providing most protection.

Relationship between human exhalation diffusion and posture in face-to-face scenario with utterance

TLDR
Human breath is visualized using the smoke of electronic cigarettes as tracer particles and shows that the exhaled breath is affected by the body wall temperature; it rises when it remains in the boundary layer by wearing a mask and diffuses randomly without a mask.

Aerosol penetration and leakage characteristics of masks used in the health care industry.

Outward and inward protections of different mask designs for different respiratory activities

TLDR
It is shown that cloth and surgical masks with a non-woven filter layer can achieve a combined outward and inward protections between 50% and 90% and double masking or the wearing of cloth mask on top of a surgical mask is only effective at reducing outward droplet emissions when coughing, while offering no additional protection when exhaling/inhaling.

Analytical and Numerical Investigation of the Airflow in Face Masks used for Protection against COVID-19 Virus –Implications for Mask Design and Usage

TLDR
The hypothesis that the impaired protection of face masks is mainly due to imperfect fitting of the masks is investigated, so that airflow, which contains virus-transporting droplets, can leak through gaps into or out of the mask.
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