The current pandemic caused by the deadly Coronavirus (SARS-CoV-2) is called as Coronavirus Disease (COVID-19). Rolling data indicate that it has affected 222 countries, areas or territories with cases, infected 77,862,704 individuals out of which 1,712,010 have died. Although, the virus has catastrophic effects, it has also indirectly nourished the nature by reducing pollution. Environmental factors such as air pollution cause diseases such as bronchitis, asthma and many other respiratory syndromes and acts as the main modulating factor for COVID-19. COVID-19 and air pollution cause mainly respiratory disorders and therefore, have intricate relations with each other. Particulate matters (PMs) have crucial contribution for air pollution. The surface areas of PM2.5 with radius (r∼1.25 µm) and PM10 (r∼5 µm) would be (using formula 4 πr2) 19.63 and 314.16 µm2, respectively. And, the diameter of SARS-CoV-2 ranges from 0.065 to 0.125 µm (average radius 0.095 µm) and would have an average surface area of ∼0.11 µm. So, theoretically, a solid PM2.5 and PM10 can carry about 95 and 2856 SARS-CoV-2 particles, respectively. Liquid PMs may carry even more virus particles as they can occupy the internal space also. So, PMs increase the risk of SARS-CoV-2 infection. Probably for this reason, COVID-19 cases are very high in few countries such as India and Italy where, air pollution is more as compared to countries that experiencing low or no air pollution. Therefore, use of appropriate mask even indoors is recommended where air pollution and COVID-19 together made their common hot spots. Use of home-made masks prepared with normal fabrics that cannot not filter aerosols or PMs are highly discouraged. Plausible data are available about the association of COVID-19 with temperature and humidity. A mega study indicates that environmental temperature and humidity show negative correlation with COVID-19 infection rate although data sometimes is opposite. Similarly, SARS-CoV-2 strains are also found in water circulation system especially in water discharged bodies. Therefore, multifactorial environmental implications epically controlling air quality is important for COVID-19 pandemic.
Chapter 3 - Role of environmental factors in transmission of COVID-19