Using PM10 geochemical maps for defining the origin of atmospheric pollution in Andalusia (Southern Spain)

In this work we present a detailed study of atmospheric PM10 pollution in Andalusia (Southern Spain) based on geochemical maps. The study includes determination of PM10 levels and bulk chemical composition with samples from 17 representative monitoring stations (rural, urban background, traffic hot spot, and urban zones with industrial influence) during 2007. The knowledge of background levels and concentrations of relevant chemical compounds and elements allows the quantification of the main sources of pollution in relevant cities and sites of ecological interest.In comparison to other stations in Spain and mainland Europe, PM10 in Andalusia is characterized by high levels of crustal matter and secondary inorganic components (SIC). This has been attributed to the following causes: 1) High road traffic and industrial emissions, 2) High frequency of North African air mass outbreaks contributing between 3 and 4 μg m−3 in western Andalusia and 4–7 μg m−3 in eastern Andalusia, and 3) Climate factors such as low rainfall, dry soils favouring resuspension, and high photochemical activity.Atmospheric particulate matter in urban areas located in the vicinity of industrial estates is enriched in secondary inorganic compounds and metals. Three main hot spots have been identified according their high trace element concentrations: Huelva (As, Cu, Zn, Se, and Bi), Strait of Gibraltar (V, Ni, Cr, and Co) and Bailén (V and Ni). The transport of pollutants from cities and industrial estates to areas of ecological interest (e.g. Doñana National Park) has been found to cause the increase in background levels in a number of trace elements (e.g. As) in the air. An important outcome of this study is that geochemical maps of atmospheric matter are a powerful tool for illustrating spatial variation patterns of geochemical components and identifying specific pollution hot spots.