ELEMENTAL ANALYSIS OF PARTICULATE MATTER AND SOURCE IDENTIFICATION INLISBON

A Gent PM10 air sampler with stacked filter units was used to collect size-fractionated aerosol samples in Lisbon between October 1993 and J anuary 1995. Sampling was made on a twice-a-week basis (one weekend da y and one midweek day). The filter loads were measured by gravimetry a nd elemental analyses were carried out by PIXE and INAA techniques. Th e complementarity of the techniques allowed the determination of the c oncentrations of 22 elements in more than 30% of all samples. Monitori ng of NO, NO2, CO and SO2 concentrations was also performed. Time vari ations for both total particulate mass and elemental concentrations ar e presented Weekend and midweek data are compared. Enrichment factors were calculated for the fine and coarse fractions and the ratios betwe en the two fractions were derived. Principal components analysis was a pplied to the identification of aerosol sources. Correlations were fou nd between the gases and coarse particle elemental concentrations. A t endency for a concentration increase in the total suspended particle m ass was observed at the end of each year. The concentration pattern fo r the rare earth elements measured was altered owing to the activity o f a nearby refinery. (C) 1998 John Wiley & Sons, Ltd.