Abstract
This study aims to explore the relationship between ambient NO(2) levels and the transmission ability (basic reproductive number, R(0)) of COVID-19 in 63 Chinese cities. After adjustment for temperature and relative humidity, R(0) was positively associated with NO(2) concentration at city level. The temporal analysis within Hubei province indicated that all the 11 Hubei cities (except Xianning City) had significant positive correlations between NO(2) concentration (with 12-day time lag) and R(0) (r > 0.51, p < 0.005). Since the association between ambient NO(2) and R(0) indicated NO(2) may increase underlying risk of infection in the transmission process of COVID-19. In addition, NO(2) is also an indicator of traffic-related air pollution, the association between NO(2) and COVID-19's spreadability suggest that reduced population movement may have reduced the spread of the SARS-CoV-2.