SARS-CoV-2 variants and environmental effects of lockdowns, masks and vaccination: a review

Abstract

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is continuously evolving and four variants of concern have been identified so far, including Alpha, Beta, Gamma and Delta variants. Here we review the indirect effect of preventive measures such as the implementation of lockdowns, mandatory face masks, and vaccination programs, to control the spread of the different variants of this infectious virus on the environment. We found that all these measures have a considerable environmental impact, notably on waste generation and air pollution. Waste generation is increased due to the implementation of all these preventive measures. While lockdowns decrease air pollution, unsustainable management of face mask waste and temperature-controlled supply chains of vaccination potentially increases air pollution.

Keywords: Air pollution; COVID-19 vaccination; Delta variants; Environmental impact; Face masks; SARS-CoV-2; Waste generation.

Fig. 1

Structure and entry in a cell of the severe acute respiratory syndrome coronavirus 2. Angiotensin-Converting Enzyme 2 (ACE2) is located on the membrane surface of host cells. The entry of the virus into host cells is mediated mainly by the use of spike protein. The lipid envelope is studded with several spike glycoproteins giving the virus a crown-like appearance. Reprinted with permission of Elsevier from (Naqvi et al. 2020)

Fig. 2

Scientific name, detection country, year of detection, mutation and transmissibility of different variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (ACI 2021). Four variants of concern including Alpha, Beta, Gamma and Delta have been identified so far

Fig. 3

Countries reporting variants Alpha, Beta, Gamma and Delta, as of 13^th August 2021. Worldwide 185 countries have reported Alpha, 136 countries Beta, 81 countries Gamma and 142 countries Delta variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, WHO, 2021). Map was created in Microsoft Excel using the data from World health Organisation

Fig. 4

Transmission route of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from human to human (Karia et al. 2020). Severe acute respiratory syndrome coronavirus 2 can be transmitted from the infected host by droplet transmission, fomites, gastrointestinal secretion, and aerosol-generating pathway

Fig. 5

Environmental impact of different protective measures including lockdown, wearing personal protective equipment (PPE) and vaccines to limit the spreading of different variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Lockdown lowers air pollution, greenhouse gas emission (GHG) and improve air quality while vaccination increases energy consumption, waste generation, air, water and soil pollution

Fig. 6

Environmental fate of microplastics that originate from face masks (Akber Abbasi et al. 2020). Microplastic generated from facemasks due to ultraviolet light and high temperature can end up in the terrestrial and aquatic environment and affect human health and aquatic organisms

Fig. 7

Comparison of particulate matter (PM_2.5) and ozone (O₃) emission of Sydney city between before and after lockdown (NSW 2021). Both particulate matter and ozone have been decreased due to the implementation of lockdown in Sydney

Fig. 8

Change of mobility patterns in Sydney due to the implementation of lockdown (Google 2021). The mobility due to lockdown in retail, supermarket, parks, public transport, and workplaces has been reduced up to 67% and residential mobility has been increased by 15%