Long time series analysis of air quality data in the Veneto region (Northern Italy) to support environmental policies

The world population is demonstrating an increasing awareness about the ecological impacts of air quality, including impacts on human health. The Veneto region and, more generally, the Po Valley (NE Italy), are characterised by frequent exceedance of limit values for air quality, in particular particulate matter (PM10), which causes these areas to be listed as hotspots; thus, this region has some of the worst air pollution in Europe. The aim of the current research was to analyse a 10 year-long time series of air quality data (2011–2021) in the Veneto region to investigate the influence of selected factors on air quality, such as natural processes (meteorological conditions), environmental policies, and health emergency measures due to the COVID-19 pandemic. Generally, the considered pollutants, PM10, NO, and NO2, presented a decreasing trend during the last ten years. The reduction in nitrogen oxides was clearly improved after the implementation of a specific environmental protocol (the “New Agreement of Po Valley Basin”). Conversely, the PM10 concentration seemed to be affected by other important emission sources, such as domestic heating systems, agricultural activities, and animal farms, which are not as strongly regulated as emission sources such as traffic. The 2020 lockdown mainly influenced nitrogen oxide concentrations