Effect of ambient air pollutants and meteorological factors on COVID-19 transmission

Abstract Background Since its first appearance in Wuhan China in December 2019, the coronavirus disease 2019 (COVID-19) has become a worldwide pandemic. Although the COVID-19 is known to cause by human-to-human transmission, it remains largely unclear whether ambient air pollutants and meteorological factors could promote its transmission process. Methods We conducted a retrospective cohort study to understand the correlation between COVID-19 incidence and eight ambient air pollutants (PM2.5, PM10, SO2, CO, NO2, and O3-8 h) and three meteorological variables (temperature, humidity and wind level) in China’s two worst-hit cities, Wuhan and XiaoGan, between Jan 25th to Feb 29th in 2020. Results Our data showed that the COVID-19 incidence was constantly correlated with PM2.5, NO2 and local temperature in both cities. Specifically, in Wuhan, the tightest correlation was observed between NO2 and COVID-19 incidence (R2 = 0.329, p < 0.01). The PM2.5 and CO also present tight correlation with the incidence number, whose R2 equaled 0.174 (p < 0.01) and 0.203 (p < 0.05), respectively. In XiaoGan, in addition to the PM2.5 (R2 = 0.23, p < 0.01) and NO2 (R2 = 0.158, p < 0.05), a notable correlation was also observed between the PM10 and incidence cases (R2 = 0.158, p < 0.05). Moreover, temperature is the only meteorological factors that constantly correlated well with COVID-19 incidence in both Wuhan and XiaoGan, but in a negative pattern (R2 = 0.126 and 0.13, respectively, both p < 0.05). Conclusion Our data concludes that ambient air pollutants, especially PM2.5 and NO2, and temperature are three variables that could potential promote the sustained transmission of COVID-19. Thus, personal protective devices, especially the facial mask and eye goggle, shall be suggested to residents for SARS-CoV-2 protection in highly polluted regions.