The size-segregated concentrations for elements from Na to Th in the fine (particle equivalent aerodynamic diameter (EAD) < 2 ?m) and coarse (2 ?m < EAD < 10 ?m) fractions were obtained by SFU (stacked filter unit) sampling on Nuclepore polycarbonate filters coupled with PIXE (particle induced X-ray emission) and INAA (instrumental neutron activation analysis) analysis [Maenhaut and Zoller, 1977; Maenhaut and Raemdonck, 1984]. The collection time per sample varied between 1 and 2 days. BC concentrations were measured via a light reflection technique [Andreae, 1983; Andreae et al., 1984]. The organic carbon (OC) and elemental carbon (EC) concentrations were obtained via a thermal-optical transmission technique [Birch and Cary, 1996]) on Whatman QM-A quartz fiber filters.
Highly size-segregated aerosol samples (12 fractions in the size range 0.045–15 ?m EAD) were collected using a small-deposit-area low-pressure impactor (SDI) [Maenhaut et al., 1996a]. The SDI was operated at a flow rate of 11 L min–1. At this flow rate, cut points were 8.5, 4.1, 2.7, 1.7, 1.1, 0.77, 0.59, 0.34, 0.23, 0.15, 0.086 and 0.045 ?m. These cut points are to be interpreted as the lower limits for the size range collected by the stage. Samples were analyzed using PIXE only.