SLow Onset Disasters (SLOD) are responsible for the production of systemic effects on the urban ecosystem and can seriously harm people to be living in the cities. Among the environmental factors discussed by D2.2.1, air pollution is one of the most critical agents in this context. The actions carried out by D2.2.2 use open data provided by the Lombardy region on the main pollutants (Particulate Matter (PM) concentration, CO, SO2, O3, NO2, black carbon and Volatile Organic Compounds (VOC)) during the period of 2017-2020. An Air Quality Index (AQI) is calculated in this reference period by comparing their concentration with established healthy threshold limits. Only in this way, the definition of effective SLODs mitigation strategies will can be provided.