Water-soluble components in PM10 aerosols over an urban and a suburban site in the city of Sfax (Tunisia)

Resumen

This study examines the influence of source and meteorological factors on the physico-chemical characteristics of atmospheric aerosols collected at two sampling sites, urban and suburban, in the city of Sfax (Tunisia) during the year of 2004. Atmospheric aerosols were further analyzed for their chemical composition and spatio-temporal evolution was investigated. Based on particle content distribution, the species studied were classified into distinct groups with different content and temporal distribution. A principal component analysis (PCA) revealed a clear relationship between the behavior of the constituents of each group and their corresponding source and meteorological factors. The findings provide sheer evidence for a marked intra-site enrichment that depended on the soil state, the frequency of exposition to the industrial plumes and the transport phenomena. Source apportionment revealed three major groupings. Group I consisted of a natural source including maritime (Cl- et Na+) and crustal (Ca++, Mg++, Fe(2;3)+ and K+) elements. Group II is associated with a ?primary? anthropic source attributed to the local effect of industrial plume fallouts which threatens the urban site. This mainly concerns the PO43- compound. The third group is explained by a ?secondary? anthropic source that included NH4+, NO3- and SO4= compounds resulting from the effect of gas/particles conversion processes.