Effects of air pollutants on the transmission and severity of respiratory viral infections

Abstract

Particulate matter, sulfur dioxide, nitrogen oxides, ozone, carbon monoxide, volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) are among the outdoor air pollutants that are major factors in diseases, causing especially adverse respiratory effects in humans. On the other hand, the role of respiratory viruses in the pathogenesis of severe respiratory infections is an issue of great importance. The present literature review was aimed at assessing the potential effects of air pollutants on the transmission and severity of respiratory viral infections. We have reviewed the scientific literature regarding the association of outdoor air pollution and respiratory viruses on respiratory diseases. Evidence supports a clear association between air concentrations of some pollutants and human respiratory viruses interacting to adversely affect the respiratory system. Given the undoubted importance and topicality of the subject, we have paid special attention to the association between air pollutants and the transmission and severity of the effects caused by the coronavirus named SARS-CoV-2, which causes the COVID-19. Although to date, and by obvious reasons, the number of studies on this issue are still scarce, most results indicate that chronic exposure to air pollutants delays/complicates recovery of patients of COVID-19 and leads to more severe and lethal forms of this disease. This deserves immediate and in-depth experimental investigations.

Alteration in angiotensin-converting enzyme 2 by PM1 during the development of emphysema in rats

“…Air pollution has been reported to increase the risk of SARS-CoV-2 infection [11,12]. ACE2 is considered to play an important role in regulation of SARS-CoV-2 infection ability [18].…”

“…COPD is known to cause deficits in ACE2 in the lungs [9,10]. Air pollution is a risk factor for the development of COPD, which is also suspected to be associated with the SARS-CoV-2 infection ability [11,12]. The objective of this study was to investigate the expressions of ACE2 by air pollution during the development of COPD.…”

Satellite-detected tropospheric nitrogen dioxide and spread of SARS-CoV-2 infection in Northern Italy

“…Though there is some evidence that air pollution may enhance the susceptibility to viral infections including that by SARS-CoV-2 (Barcelo, 2020;Chen et al, 2010;Domingo and Rovira, 2020;Peng et al, 2020;Tsatsakis et al, 2020), the connection is still speculative. Transmission of airborne infections such as that due to SARS-CoV-2 occurs mainly through droplets and aerosols in the vicinity of infected individuals (Gabutti et al, 2020), but airborne particles might serve as carriers for pathogens (Setti et al, 2020a;SIMA, 2020;Zhao et al, 2019).…”

Robust association between short-term ambient PM2.5 exposure and COVID prevalence in India

“…Previous literature has established associations between exposure to air pollution and spread of measles 14,15 and spread of respiratory diseases 16,17 . Speci cally, in case of COVID, studies from China 7 and Italy 8,9 have shown air pollution to be an important factor in disease transmission and mortality.…”