Assessment of effectiveness of optimum physical distancing phenomena for COVID-19

Abstract

Currently, COVID-19 is a global pandemic that scientists and engineers around the world are aiming to understand further through rigorous testing and observation. This paper aims to provide safe distance recommendations among individuals and minimize the spread of COVID-19, as well as examine the efficacy of face coverings as a tool to slow the spread of respiratory droplets. These studies are conducted using computational fluid dynamics analyses, where the infected person breathes, coughs, and sneezes at various distances and environmental wind conditions and while wearing a face-covering (mask or face shield). In cases where there were no wind conditions, the breathing and coughing simulations display 1–2 m physical distancing to be effective. However, when sneezing was introduced, the physical distancing recommendation of 2 m was deemed not effective; instead, a distance of 2.8 m and greater was found to be more effective in reducing the exposure to respiratory droplets. The evaluation of environmental wind conditions necessitated an increase in physical distancing measures in all cases. The case where breathing was measured with a gentle breeze resulted in a physical distancing recommendation of 1.1 m, while coughing caused a change from the previous recommendation of 2 m to a distance of 4.5 m or greater. Sneezing in the presence of a gentle breeze was deemed to be the most impactful, with a recommendation for physical distancing of 5.8 m or more. It was determined that face coverings can potentially provide protection to an uninfected person in static air conditions. However, the uninfected person's protection can be compromised even in gentle wind conditions.

Post-pandemic urban design: The equilibrium between social distancing and social interactions within the built environment

“…According to him, a distance of 120 cm to 350 cm is considered as the category of social distance which can be varied in terms of sensational perception due to the increasing physical distance. Although simulation studies have delineated that the measurement of the standard social distance is variable depending on different environmental circumstances, it is recommended to observe 110 cm physical distance in case of the existence of a gentle breeze ( Chea et al, 2021 ). Nowadays, people have been asked to maintain a social distance, not to bring people into their own personal territory, transfer their tasks into indoor activities (remote working), and stay in their neighborhoods as much as possible.…”

The heterogeneous regional effect of mobility on Coronavirus spread

“…With respect to the third group of factors, several studies analyse weather conditions, such as temperature [ 30 ], humidity or precipitations [ 30 – 33 ], daylights hours [ 31 – 34 ], wind speed [ 31 , 32 , 35 ] or air pollution [ 1 ]. The weather conditions are deeply interrelated.…”

“…The last analysed factor is the wind speed, which increases the number of cases and deaths [ 31 ]. The improper airflow and higher wind velocity can strongly increase the travelling distance of aerosol particles and droplets, the needed social distancing, and the risk of Coronavirus transmission [ 32 , 35 ]. A limitation to the increase of virus spread generated by the wind is the wearing face coverings (generally masks).…”

Estimates of the stochasticity of droplet dispersion by a cough

“…CFD (computational fluid dynamics) studies performed in an indoor environment 27,31,32,39,40 and outdoors 33 found similar conclusions regarding the physical distancing measures. The effect of masks on disease transmission was analyzed in several studies 32,41,42 concluding that masks can cut the droplet transmission distance significantly by suppressing the exhaled flow as well as altering the size distribution of the exhaled droplets. As mentioned, the presence of wind was also seen to assist the exhaled flow and consequently increase the distances over which the infection can be transmitted both with or without a mask.…”