LONG-TERM ATMOSPHERIC AEROSOL STUDY AT URBAN AND RURAL SITES IN BELGIUM USING MULTIELEMENTAL ANALYSIS BY PARTICLE-INDUCED X-RAY-EMISSION SPECTROMETRY AND SHORT-IRRADIATION INSTRUMENTAL NEUTRON-ACTIVATION ANALYSIS

The Ghent PM10 stacked filter unit (SFU) sampler was used to collect s ize-fractionated atmospheric aerosol samples, first at an urban reside ntial site in Ghent, Belgium, and subsequently at a rural site (Waasmu nster, about half way between the cities of Ghent and Antwerp). The sa mplings at Ghent took place in 1993-34 (over a 14 month period) and a total of 118 daily SFU samples were collected. At Waasmunster, 142 dai ly SFU samples were taken in 1994-95 (over a 16 month period). All sam ples were analyzed for the particulate mass, black carbon, and up to 2 9 elements. The elements were measured by particle-induced x-ray emiss ion spectrometry (PIXE) and short-irradiation instrumental neutron act ivation analysis (INAA). The data for common elements measured by both techniques were compared. This permitted an assessment of the magnitu de of the particle size effect for the lighter elements in PIXE. The d ata sets were subjected to receptor modeling with absolute principal c omponent analysis, and relationships between the intensities of the co mponents (i.e. the component scores) and various meteorological variab les were examined. The anthropogenic and crustal components were consi stently negatively correlated with wind speed. Overall, the aerosol co ncentrations, compositions, sources and source contributions to the pa rticulate mass were remarkably similar for the urban and rural sites. (C) 1998 John Wiley & Sons, Ltd.