Investigating the Role of Environmental Factors on the Survival, Stability, and Transmission of SARS-CoV-2, and Their Contribution to COVID-19 Outbreak: A Review

Abstract

Studies conducted in the last four years show conflicting findings on the role of the environment in the survival, stability, and transmission of SARS-CoV-2. Based on the current evidence, the factors that affect the severity of COVID-19 include host interaction, environmental stability, virus volume, stability, transmission, social interactions, and restriction measures. Moreover, the persistence of the virus depends on different environmental conditions, videlicet temperature, humidity, pH, salinity, and solar radiation. The outbreak of respiratory viruses is related mainly to temperature and humidity, and geographical locations (latitude). In SARS-CoV-2, mainly temperature and humidity seem to play a fundamental role. Moreover, studies have indicated that social health factors such as equitable health systems, hygiene, and underlying diseases have played a pivotal role in the incidence and outbreak of COVID-19. Therefore, addressing health issues associated with reducing SARS-CoV-2 outbreaks plays an essential role in global health. In contrast, the environmental stimuli of the COVID-19 outbreak are mainly unknown. Given the ongoing threat of the COVID-19 pandemic, it is important to understand the stimuli to respond quickly to emerging SARS-CoV-2 variants while implementing long-term and sustainable control strategies. This review discusses the role of environmental factors and health conditions in the outbreak of SARS-CoV-2.

Airborne SARS-CoV-2 is more frequently detected in environments related to children and elderly but likely non-infectious, Norway, 2022

“…During this time, much has been debated about the transmission of SARS-CoV-2, and how each transmission mode contributed to the worldwide spread of the virus, as well as all the factors involved in different transmission settings [2][3][4]. Now, it is well established that transmission through surfaces did not account for a great proportion of the infections, and that transmission occurs mainly through close contact, respiratory droplets and aerosols [5,6], with indoor airborne transmission likely being the main driver of the pandemic [7][8][9][10].…”

“…Strict vaccination, surveillance and control policies helped to control viral spread, however, there is still a major gap in knowledge when it comes to airborne transmission, namely: how different environmental and meteorological parameters affect virus infectivity in the environment; how long the virus survives in the air; and more importantly, what is the minimum infectious dose of the virus. This information is essential for understanding airborne transmission dynamics and how we can prevent infection more efficiently [10][11][12]. There are several inherent difficulties in studying airborne SARS-CoV-2, e.g.…”