Association between short-term exposure to air pollutants and cause-specific daily mortality in Italy. A nationwide analysis

•Time-series analysis of cause-specific mortality occurred in Italy.•Machine learning estimated daily PM10, PM2.5 and NO2 concentrations.•PM10 and PM2.5 positive associated with the mortality from nervous system causes.•NO2 positively associated only with respiratory and metabolic mortality.•Associations found in highly urbanised areas but also in suburban and rural ones.