Characterization of lead, cadmium, arsenic and nickel in PM(2.5) particles in the Athens atmosphere, Greece.

Concentrations of Pb, Cd, As and Ni in PM(2.5) particles were measured in samples collected, using low volume PM(2.5) samplers (Harvard Impactor system, HI) at two sites in Athens basin; Patission Street in Athens city center and Rentis, a semi-urban and industrial area, during March 1995-March 1996. Sample analysis for Pb, Cd, Ni and As was accomplished by electrothermal atomic absorption spectrometry after total digestion. Annual geometric mean values in 183 PM(2.5) particles samples were found to be: Pb: 143 nanogram(-3); Cd: 0.34 nanogram(-3); Ni: 4.55 nanogram(-3); As: 0.79 nanogram(-3). The geographical and temporal distribution patterns were investigated. Pb exhibited higher values during the winter period. For the other elements no significant seasonal variation was observed. Wind direction, air temperature and relative humidity affected element concentrations. Principal component analysis was applied on the data to enable source apportionment of toxic elements in PM(2.5) particles. It was found that Pb, As and Ni have common sources, which could be vehicles emissions/oil combustion and resuspended road dust. Cd and a portion of As originate from industrial activities.