Analysis and Characterization of the Predominant Pollutants in the Catania's Air Quality Monitoring Stations

It is useful to know about whether one or more pollutants predominate in different parts of a city and contributes to evaluating the efficacy of a variety of counter-measures for lowering pollutants in urban areas. This paper compares Catania (Italy) air quality measured in 2003 with that in 2012. The investigation was carried out at four monitoring stations of the city's Air Quality Monitoring Network (AQMN). The monitoring station locations had not changed from 2003 to 2012.The impact of the city's primary and secondary pollutants was estimated from analyses of the daily concentrations of CO, SO2, PM10, NO2 andO3, and then by assembling the data into classes by applying Sturge's rule which provides the optimal number of intervals (or classes). Each class provides frequency density to make comparable intervals with different amplitudes. By analysing the frequency density intervals, the prevalence of a pollutant class could be highlighted and consequently linked to a range of representative concentrations in each urban area for each year analysed. Thus, after a decade, the decrease, stability or increase in a given pollutant could be defined providing a general overview of air quality traits in Catania and giving guidelines for pollution control policies.