A systematic review of possible airborne transmission of the COVID-19 virus (SARS-CoV-2) in the indoor air environment

Abstract

At the end of December 2019, the rapid spread of the COVID-19 (SARS-CoV-2) disease and, subsequently, deaths around the world, lead to the declaration of the pandemic situation in the world. At the beginning of the epidemic, much attention is paid to person-to-person transmission, disinfection of virus-contaminated surfaces, and social distancing. However, there is much debate about the routes of disease transmission, including airborne transmission, so it is important to elucidate the exact route of transmission of the COVID-19 disease. To this end, the first systematic review study was conducted to comprehensively search all databases to collect studies on airborne transmission of SARS-CoV-2 in indoor air environments. In total, 14 relevant and eligible studies were included. Based on the findings, there is a great possibility of airborne transmission of SARS-CoV-2 in indoor air environments. Therefore, some procedures are presented such as improving ventilation, especially in hospitals and crowded places, and observing the interpersonal distance of more than 2 meters so that experts in indoor air quality consider them to improve the indoor air environments. Finally, in addition to the recommendations of the centers and official authorities such as hand washing and observing social distancing, the route of air transmission should also be considered to further protect health personnel, patients in hospitals, and the public in other Public Buildings.

Effects of the COVID-19 Pandemic on Indoor Air Quality and Thermal Comfort of Primary Schools in Winter in a Mediterranean Climate

“…Based on the findings of different studies, the transmissibility of COVID-19 can be influenced by airflow, as well as by environmental conditions. Recently, research has pinpointed aerosols as one of the transmission routes of SARS-CoV-2 [22] so that airborne transmission in indoor environments is highly likely [23].…”

“…Recent research and international guidelines published for schools' reopening [25,29] have determined the need to implement effective measures to minimise the risk of transmission, including an interpersonal distance of 2 m, face masks, frequent hygiene, temperature checks, and improved ventilation [23,24,30]. According to results, natural, hybrid, and mechanical ventilation systems can be used effectively and safely in schools, removing contaminated indoor air and supplying fresh outdoor air [26].…”

SARS-CoV-2 virion physicochemical characteristics pertinent to abiotic substrate attachment

“…Within a short time after the outbreak of the Covid-19 pandemic, an avalanche of publications have appeared, which are devoted to various aspects ranging from the SARS-CoV-2 virus transmission mechanisms [ [1] , [2] , [3] , [4]∗∗ ] its attachment to receptors and abiotic surfaces (fomites) [ [5]∗∗ , [6]∗ , [7] , [8] ], inactivation and removal [ 8 , 9 ] to vaccination. [ 10 ].…”

COVID-19 virus released from larynx might cause a higher exposure dose in indoor environment

“…Numerous studies have provided evidence of airborne transmission about COVID-19 ( Jayaweera et al, 2020 ; Kenarkoohi et al, 2020 ; Noorimotlagh et al, 2020 ; Richard et al, 2020 ). COVID-19 virus is around 100 nm in diameter ( Zhu et al, 2020 ), and usually needs to be attached to carriers for airborne transmission ( Jayaweera et al, 2020 ; Maleki et al, 2021 ).…”