Author(s)

A. Baroncelli, F. Evangelist, F. Ravegnani, P. Bonasoni & G. Giovanelli

Abstract

Urban air pollution is determined as much by emission rates and source site- location in a given area as by chemical transformations and, to a very large extent, by meteorology. Milan, northern Italy's largest metropolitan area, is situated in the northwesternmost part of the Po Valley, being bounded by the Alps to the north and to the west and the Ligurian Apennines to the south. Because of its topography and orography, and in concomitance with the area's prevailing anticyclonic circulation, the city is marked by a persistent lack of breeze, a fact that promotes the accumulation and vertical layering over the city of gaseous pollutants. Frequent diurnal and nocturnal thermal inversions as well as fumigation phenomena lead to high pollutant concentrations at ground level and the consequent violation of air quality standards. A

Keywords