CHARACTERIZATION OF THE AIR-POLLUTION IN THE URBAN AREA OF MADRID

An attempt is made to characterize for the first time the urban pollution of Madrid using the combination of conventional gas measurements and an ion beam analytical technique (PIXE) for aerosol monitoring. Different sets of samples were collected selecting different seasons of the year; winter and summer 1992, and also different sampling times; 3 h and 24 h. A group of 18 elements in the mass range from Si to Pb could be analyzed. Concentration of gases in the air was recorded for the following: CO, NOx) NO2, SO2 and CxHy. Four sources contributing to the air pollution were obtained by means of absolute principal component analysis where automotive transport emerges as the dominating one. The combination of aerosol (PIXE) and gas data as input to a receptor model proved to be fruitful for the understanding of the underlying chemical and physical processes governing the observed pollution levels. This is a preliminary study whose results will supply the trends and strategies for a more thorough characterization.