ABSTRACT
Residents and public officials in urban areas around the world are concerned about traffic congestion and air pollution. Traffic congestion and air pollution are exemplified in the city of Seville with a historic centre formed by very narrow streets. One of the streets conducting to the very centre of the city is Constitution Avenue, which is delimited in one of the sides by the cathedral. For more than five decades, exhaust emissions from gasoline-and diesel-powered vehicles contributed to the deterioration of the cathedral of Seville. The years 60-80 were particularly harmful for the cathedral, since the trams were substituted by diesel buses. Until the mid-90s the belt of narrow streets surrounding the cathedral was fully active, routing all the traffic of the city centre as well as serving the surrounding areas, with continuous traffic congestion. In addition, the squares facing the eastern and southeastern façades were used as parking lots. Today, the traffic has been partially restricted, but only under the northern, southern and eastern façades, while intense traffic continues on Constitution Avenue where the main façade and the Birth, Assumption and Baptism portals, with sculptures from the 15th and 19th centuries, are located. It is on this narrow street where the greatest concentrations of gases and aerosols are reached as it routed all downtown traffic. The particular situation of the western façade permits to investigate the impact of air pollution on the cathedral and with this aim an aerosol monitoring was carried out. The data obtained are reported by Cachier et al. (2004). This paper focuses on organic characterization of the sampled aerosols. A few weeks every year, in Holy
Week, the Sevillian municipality introduces traffic regulations resulting in partial or total closure of the street for religious processions. A study on the chemical composition of aerosols sampled at different periods of the year under distinct traffic regimes is presented. The aerosol composition was compared with previously studied black crusts from the cathedral.
