Carbonaceous and ionic compositional patterns of fine particles over an urban Mediterranean area

A carefully designed experimental study based on the monitoring of fine airborne particles, was carried out at three different locations (suburban background, traffic-industrial, coastal background) of an urban Mediterranean area, the Athens Basin. Understanding of the PM2.5 and PM1 nature has an important policy implication. In total, five hundred and nineteen samples were chemically analyzed with respect to carbonaceous (organic/elemental carbon) and ionic (NH4+, K+, Mg2 +, Ca2 +, NO3−, Cl−, SO42 −) species. The dataset consists one of the very few in the Mediterranean which simultaneously deals with the carbonaceous and ionic components of fine aerosol fractions, especially for PM1. Daily PM2.5 averages often exceeded the E.U. limit values, with their mass being mainly composed of PM1. The most important constituents of secondary particles were SO42 − and organic carbon, with both accounting for 56.4%-64.3% and 60.5%-62.3% of the total PM2.5 and PM1 mass, respectively. Regional sources, marine/crustal elements, combustion sources and traffic were indicated by factor analysis as the greatest contributors to the mass of both PM2.5 and PM1 fractions, accounting for 85.3% and 83.6%, respectively of the total variance in the system. It is worthy to note, the key role of the prevailing atmospheric conditions to the configuration of the obtained picture of the particulate pollution.

► One of the very few Mediterranean PM2.5, PM1 ionic and carbonaceous species datasets. ► Factor analysis indicated 4 sources. ► PM fractions are mainly composed of sulfates and organic carbon. ► Aerosols patterns are related to both regional and local sources. ► Atmospheric conditions have obvious impact on the pollution picture of an area.