Published in Atmospheric Pollution Research, the article “Lessons learnt for air pollution mitigation policies from the COVID-19 pandemic: The Italian perspective” is the result of a collaboration between ENEA, Arianet s.r.l., and ARPA Lazio, focusing on the effectiveness of anthropogenic emission reduction plans for improving air quality.
In 2020, the outbreak of the COVID-19 pandemic led to a significant reduction in anthropogenic pollutant emissions, providing an unexpected opportunity to observe the consequences on ambient concentrations. Using the national lockdown in Italy from March to May 2020 as a case study, this work aims to deduce if and what lessons can be learned regarding the impact of emission reduction policies on air quality.
Variations in NO2, O3, PM10, and PM2.5 concentrations were calculated from numerical model simulations using both BAU (Business As Usual) emissions and emissions specific to the lockdown period.
Both simulations were performed at the national level with a horizontal resolution of 4 km and at the local level for the capital Rome with a resolution of 1 km. The simulated concentrations showed good agreement with in situ observations, confirming the ability of the modeling systems to reproduce the effects of emission reductions on concentration changes in the environment, which vary depending on the specific atmospheric pollutant; generally, a reduction in pollutant concentrations was observed, except for ozone, which increased in Rome and other urban areas, and decreased elsewhere.
The results suggest that addressing precursor emissions, even with significant reductions like those experienced during the lockdown period, can lead to meaningful, though complex, reductions in secondary pollutant concentrations. Therefore, to be more effective, reduction measures should be carefully selected, involving more sectors beyond mobility, such as residential and agricultural, and integrated across different scales.