Statistical analysis of surface atmospheric pollutant measurement series for various sites across the Po valley

In order to assess recent changes in the concentration of pollutants in the Po valley, ten-year or longer time series of atmospheric pollutants have been analyzed, including both traffic and background sites (either urban, suburban or rural) at main towns and cities in the Po valley. The dataset comprise pollution data from Regional Environmental Agency monitoring networks; all data are referred to actual sampling condition, as by 2008/50/EC. Weekly pattern at each site has been estimated, in order to assess pollution condition and anthropogenic sources influence at each station. Time series have been checked for significant change in de-seasonalized mean monthly concentration and in annual median concentration. Mean daily concentration data have been tested for significant weekly (i.e. anthropogenic) cycles. Long term trend of atmospheric pollutants has been estimated via parametric and non-parametric methods. Finally, cluster analysis has been applied in order to highlight stations sharing similar pollution conditions over the reference period.