Statistical evaluation of elemental composition data of PM10 air particulate in Sofia

This study reviews the elemental composition data of PM10 obtained in six experimental campaigns run in February, July, October and December 2012 and in January-February and July 2013. The PM10 quartz fibre filters were collected with TECORA low volume PM10 sampler at the Central Meteorological Observatory in Sofia. The concentration of more than 20 macro and micro elements was measured by ED-XRF technique. The higher PM10 daily concentrations are related to the higher concentrations for most of the elements. Ag, K, Ca and Fe show high values in summer when PM10 concentration is low. The concentrations from element to element may vary in three orders of magnitude. HYSPLIT and FLEXTRA trajectory models were used to study the transport of air masses with higher silver concentrations, observed in July 2012 in Sofia. The multivariate techniques factor analysis (FA) and principle components analysis (PCA) were applied for source identification of the elemental composition data.