Impact assessment on air quality in Lombardy of the limitations for contrasting the diffusion of COVID-19

In this paper, ARPA Lombardy presents the simulation results and a preliminary impact assesment on air quality due to the introduction of limitation and social distancing rules for contrasting the diffusion of COVID-19 disease. A specific data flux and methodology have been developed on the base of the most recent emission inventory available for the Lombardy region and algorithms, ad hoc built up for the study, to estimate the primary emission variations of the main atmospheric pollutant, potentially affected by the anti-COVID rules. Two emission scenarios have been identified:”BAU”, defined as business as usual, and”COVID”, defined as the situation expected during the period. The main emission estimates on a daily base have been used as input in the chemical transport model FARM for evaluating the impact of lockdown on air quality in Lombardy. Simulated data have been also assimilated with measurements in 2020 and measured data in the three previous years 2017-2019. © 2020 HARMO. All rights reserved.