Characterisation of individual atmospheric particles within the royal museum of the Wawel castle in Cracow, Poland

Aerosol particles collected inside the museum of the Wawel Castle in Cracow, Poland, were characterized with respect to their size and composition. Two micro-analytical techniques, electron probe microanalysis (EPMA) and micro Raman spectrometry (MRS) were applied. These techniques provide the elemental composition and the molecular identification of the particles, respectively. To distinguish between particle types, the hierarchical cluster analysis (HCA) was applied independently to each size fraction. The fine fraction consisted mostly of amorphous carbon (including soot), while in the micrometer fraction a significant amount of amorphous carbon agglomerated with the omnipresent ammonium sulphate appeared. Many of the larger particles were complex agglomerates. The larger particles contained more soil-derived particles. Organic particles were very important too, and an unexpected contribution by Cu-rich particles, probably from the wear of the huge Flemish tapestries exhibited in the museum, was observed.