NO 2 Pollution Over the Po Valley in 2018-2021 and its Possible Effects in Boosting COVID-19 Deaths

This work analyzes nitrogen dioxide (NO2) pollution over the Po Valley in northern Italy, using both satellite and in situ observations. The analysis has been performed for a three-year time from May 2018 to April 2021, covering the period January 2020-April 2020 of COVID-19 diffusion over the Po Valley. The region has been the first site of COVID-19 diffusion in Europe, with a higher mortality rate than in other parts of Italy and Europe. The study aimed at giving a more general picture of the NO2 temporal and spatial variation, possibly due to the lockdown adopted to the pandemic crisis containment and other factors, such as the meteorological conditions and the seasonal cycle. We have mainly investigated two effects: first, the correlation of NO2 pollution with atmospheric parameters such as air and dew point temperature, and second the possible correlation between air quality and COVID-19 deaths, which could explain the high mortality rate. We have found a good relationship between air quality and temperature. In light of this relationship, we can conclude that the air quality improvement in March 2020 was primarily because of the lockdown adopted to prevent and limit virus diffusion. We also report a good correlation between NO2 pollution and COVID-19 deaths, which is not seen when considering a reference city in the South of Italy. The critical factor in explaining the difference is the persistence of air pollution in the Po Valley in wintertime. We found that NO2 pollution shows a seasonal cycle, which correlates with the COVID-19 deaths. A result, which, once read in the context of current and recent epidemiological evidence, leads us to conclude that air pollution may have acted as a significant risk factor in boosting COVID-19 fatalities.Funding: This research has been supported by Italian Ministry of Education, University and Research in the framework of the project “OT4CLIMA” (D.D. 2261 del 6.9.2018, PON R&I 2014-2020 and FSC).Declaration of Interests: The authors have nothing to declare.