Exposure to air pollution and COVID-19 severity: A review of current insights, management, and challenges.

Several epidemiological studies have suggested a link between air pollution and respiratory tract infections. The outbreak of coronavirus disease 2019 (COVID-19) poses a great threat to public health worldwide. However, some parts of the globe have been worse affected in terms of prevalence and deaths than others. The causes and conditions of such variations have yet to be explored. Although some studies indicated a possible correlation between air pollution and COVID-19 severity, there is yet insufficient data for a meaningful answer. This review summarizes the impact of air pollution on COVID-19 infections and severity and discusses the possible management strategies and challenges involved. The available literature investigating the correlation between air pollution and COVID-19 infections and mortality are included in the review. The studies reviewed here suggest that exposure to air pollution, particularly to PM2.5 and NO2 , is positively correlated with COVID-19 infections and mortality. Some data indicate that air pollution can play an important role in the airborne transmission of SARS-CoV-2. A high percentage of COVID-19 incidences has been reported in the most polluted areas, where patients needed hospital admission. The available data also show that both short-term and long-term air pollution may enhance COVID-19 severity. However, most of the studies that showed a link between air pollution and COVID-19 infections and mortality did not consider potential confounders during the correlation analysis. Therefore, more specific studies need to be performed focusing on some additional confounders such as individual age, population density, and pre-existing comorbidities to determine the impact of air pollution on COVID-19 infections and deaths. Integr Environ Assess Manag 2021;17:1114-1122. © 2021 SETAC.

Assessment of the role of zinc in the prevention of COVID-19 infections and mortality: A retrospective study in the Asian and European population.

Several studies have demonstrated an association between individual zinc status and viral respiratory infections; however, evidence regarding COVID-19 is still missing or insufficient. This study aimed to evaluate the correlation between the prevalence of zinc deficiency and COVID-19 cases and deaths per million population in the Asian and European countries. The COVID-19 data from two different time points, that is, May 30 and June 30, 2020 for the Asian population and May 15 and June 15, 2020 for the European population, were analyzed to determine the correlation with the estimated zinc deficiency for these two continents. The prevalence of zinc deficiency was about two times higher in the Asian population (mean 17.5%) than in the European population (mean 8.9%). A significant positive correlation (p < .05) was observed between the prevalence of zinc deficiency and COVID-19 cases at both time periods for the Asian population. However, the correlation between zinc deficiency prevalence and COVID-19 deaths was not significant in the Asian population. In contrast, a significant but negative correlation (p < .05 for all cases) was observed for zinc deficiency with both COVID-19 cases and deaths per million population at both time periods in the European countries. Considering the direct antiviral properties of zinc, it can be suggested that zinc supplementation may be beneficial for most of the population, especially older people and those who are at risk of COVID-19 infections. In conclusion, there is not enough evidence on the association between individual zinc status and COVID-19 infections and mortality. Therefore, cohort studies and randomized controlled trials are required to test this hypothesis.