What is suitable social distancing for people wearing face masks during the COVID‐19 pandemic?

Abstract

COVID‐19 has caused the global pandemic and had a serious impact on people's daily lives. The respiratory droplets produced from coughing and talking of an infected patient were possible transmission routes of coronavirus between people. To avoid the infection, the US Centers for Disease Control and Prevention (CDC) advised to wear face masks while maintaining a social distancing of 2 m. Can the social distancing be reduced if people wear masks? To answer this question, we measured the mass of inhaled droplets by a susceptible manikin wearing a mask with different social distances, which was produced by coughing and talking of an index “patient” (human subject) also wearing a mask. We also used the computational fluid dynamics (CFD) technology with a porous media model and particle dispersion model to simulate the transmission of droplets from the patient to the susceptible person with surgical and N95 masks. We compared the CFD results with the measured velocity in the environmental chamber and found that the social distancing could be reduced to 0.5 m when people wearing face masks. In this case, the mass concentration of inhaled particles was less than two people without wearing masks and with a social distancing of 2 m. Hence, when the social distancing was difficult, wearing masks could protect people. We also found that the leakage between the face mask and the human face played an important role in the exhaled airflow pattern and particle dispersion. The verified numerical model can be used for more scenarios with different indoor environments and HVAC systems. The results of this study would make business profitable with reduced social distancing in transportation, education, and entertainment industries, which was beneficial for the reopening of the economy.

Airborne transmission of COVID‐19 virus in enclosed spaces: An overview of research methods

“…Furthermore, social distancing can be influenced by other intervention measures, such as the wearing of face masks. Deng and Chen 71 measured and simulated the mass of droplets inhaled by a susceptible manikin wearing a mask with different degrees of social distancing. They found that the distance can be reduced to 0.5 m when people wear masks.…”

Recent progress on studies of airborne infectious disease transmission, air quality, and thermal comfort in the airliner cabin air environment

“…The passenger did not wear his/her mask for a period of 1 h. Wearing mask is very important in airplane cabins where social distancing is difficult. Deng and Chen 71 found that wearing surgical masks can reduce the necessary social distance from 2 to 0.5 m.…”

“…The passenger did not wear his/her mask for a period of 1 h. Wearing mask is very important in airplane cabins where social distancing is difficult. Deng and Chen71 found that wearing surgical masks can reduce the necessary social distance from 2 to 0.5 m.The literature has documented airborne transmissions of SARS-CoV-2 in airliner cabins, although airplane manufacturers seemed to downplay the significance. The spread was probably caused by the mixing ventilation used in current air cabins.…”

Elucidating the role of environmental management of forests, air quality, solid waste and wastewater on the dissemination of SARS-CoV-2

“…Filtered 95, surgical, polycotton and polyprop masks have shown lesser particle travel than masks without polymers ( Chughtai et al, 2020 ; Fischer et al, 2020 ; Li et al, 2020b ). However, since there is less access to medical grade masks, promoting correct ways of wearing protective masks made with two or three layers of cotton, along with face shields or disposable masks have been recommended ( Arumuru et al, 2020 ; Aydin et al, 2020 ; Fischer et al, 2020 ; Missoni et al, 2021; Shen et al, 2020b ; Li et al, 2020b ; Brooks et al, 2021 ; Deng and Chen, 2021 ; Clapp et al, 2021 ; Tanisali et al, 2021 ). Quilt and Cotton 600 TPI are also recommended to construct safe and reusable masks for general use, but reduced filtration efficiency of cotton masks post daily wash has been found ( Chughtai et al, 2020 ; Maher et al, 2020 ; Hartanto and Mayasari, 2021 ).…”