EDXRF characterisation of elemental contents in PM2.5 in a medium-sized Swedish city dominated by a modern waste incineration plant

Energy dispersive x-ray fluorescence (EDXRF) analysis of airborne particles has previously been shown to be a powerful technique for identifying key elements or elemental ratios for identification of important sources of air pollution. In the present work the technique was used for assignment of major sources of aerosol particles (PM2.5) in a medium sized Swedish city in southwestern Sweden, in which a new incinerator of household and industrial waste had recently been installed. Data on particle mass and black carbon contents in PM2.5 were also recorded together with SO2 and NO2 during the same study period. In spite of the small data set it was possible to identify five major sources for collected PM2.5, namely, waste incineration together with other local sources, oil incineration, biomass burning, long-distance transport and traffic emissions. Major characteristic elements for the respective sources were identified from regression analysis of the data and from information obtained in previous studies. A receptor model based on the use of trace observations was used for quantitative calculation of the source contribution to PM2.5. The relative strength of the identified sources was seen to change when the variables included in the analysis were varied in number and character, although the same sources remained. It must be noted that the quantitative contribution from the different sources maybe treated only as informative at present, since the number of observations are small compared to the number of variables. Copyright (C) 2007 John Wiley & Sons, Ltd.