Source identification of trace elements emitted into Athens atmosphere

Abstract

The source identification of trace elements emitted into Athens (Greece) atmospheric environment has been studied by the Enrichment Factor (EF) and by Principal Component Analysis (PCA). The prevailing wind direction is related to EF data in order to identify the possible pathways of trace elements, in the Athens basin. As gas pollutants and trace elements could be emitted from the same source, the possible relation between these two groups is studied by PCA and correlation relations. According to EF data, the trace elements Fe, Sm, Th, Co, Sc, Cr and K have a crustal origin while the elements Zn, As, Sb, Ag, Br result of anthropogenic pollution. The study of the prevailing wind direction showed that the existing geophysical channel in the northern area of Athens basin could be a pathway for the entrance of Fe, La, Sm, Th, Co, Cr, Na and Ag into Athens atmosphere. On the contrary, the sea breeze could be a potential cleaner of the atmosphere from the same elements. Six source factors were resolved by PCA for all the Athens area explaining the 90% of the total variance. They could nominated as soil dust, central heating, movement of cars, car tires, car break abrasion and sea breeze. After the application of PCA and the linear regression model, the concentration of atmospheric ozone shows to have a positive significant correlation with Na and Zn and a negative significant correlation with As, Br, Ce, Co, Cr, Fe, La, Sb, Sc, Sm. A possible explanation of the mechanism for the decrease of atmospheric ozone concentration in relation to trace metals is given according to the existing literature data.