PM2.5 and associated ionic component concentrations inside the archaeological museum of Thessaloniki, N. Greece

PM2.5 and its associated ionic component concentrations (Cl−, Br−, F−, NO3−, NO2−, SO42−, HCOO−, CH3COO−, H2PO4−, Na+, K+, NH4+, Ca2+, Mg2+) were determined in the Archaeological Museum of Thessaloniki (AMT), in Northern Greece, where sculptures and other antiquities dated from the Archaic, Classical, Hellenistic and Roman times are displayed. Indoor and outdoor PM2.5 samplings were concurrently carried out over a 3-month period. Both sites showed similar temporal variations with indoor PM2.5 concentrations exceeding outdoor levels. Resuspension of soil dust particles introduced by visitors and restoration works carried out during sampling campaign were concluded as being major indoor sources for fine particles and associated calcium. Sulfate was found to be the dominant ion in indoor aerosol originating from external penetration rather than indoor sources. Increased indoor acidity was also observed resulting from the potential presence of partially neutralized ammonium sulfate.