NO2 Concentrations and COVID-19 in Local Systems of Northwest Italy

This paper aims to further investigate the relationship between the concentrations of nitrogen dioxide (NO2) and the severity of COVID-19 by analyzing the data of three Italian Regions (Piedmont, Valle d’Aosta and Liguria) during the first wave of the pandemic (February–May 2020). The analyses were conducted at a local scale using Local Labor Systems of ISTAT. The annual average of NO2 concentrations, obtained from space satellite Sentinel-5P, was used to assess environmental data. While excess mortality data were used to estimate the severity of the pandemic, calculated as the percentage change in deaths recorded in 2020 compared to the average number of deaths of the previous five years (2015–2019). Using quasi-Poisson multivariate regression models, it was possible to estimate the correlation between the incidence rate of the pandemic and some risk factors, including in particular the concentration of NO2.