Source characterisation of fine urban particles by multivariate analysis of trace metals speciation

A series of 41 samples of atmospheric particles below 0.61 μm were collected at 12 sites in a Mediterranean city. Meteorological data were related to analytical data. Direct observation technique was used to support the results. Total content and chemical form concentrations for 11 metals were determined, the chemical forms being determined through a specific speciation scheme for fine particles. All sampling sites were differentiated according to the level of metallic pollution. These levels were 40% higher on weekdays than at weekends. Organic-sulphidic chemical form levels of Cd, Pb, Mn and Ti were highest on weekdays. Sources from the sampling sites were influenced by local emissions more than by transferred pollution. Various sources were identified by a sequential principal component analysis as the resuspended soil particles, oil combustion, emissions from foundries and traffic.