In this study we characterize the long-range transport of allergenic pollen to the North East of Spain. To this end, cluster analysis of back-trajectories and a source-receptor model was applied to a dataset of 10 years of airborne monitoring data corresponding to the period 2000-2009. The aim of the study is to examine and interpret the main transport routes and source areas affecting levels in Catalonia for a total of 20 pollen types. The cluster analysis of trajectories revealed that trajectories entering to the region by East France represent well the long distant transport of some taxa which are scarce in the Catalan territory or present only in limited areas (Ambrosia, Betula, Corylus and Fagus) together with other common in Catalonia (Fraxinus, Quercus deciduous type and Pistacia) showing agreement with the source areas obtained from the source-receptor methodology: Whereas, for taxa with local/regional sources (Artemisia, Castanea, total Poaceae, Plantago, total Polygonaceae, Olea, total Quercus and Quercus evergreen type) with high concentration levels associated to situations of recirculation over the Iberian Peninsula, the source-receptor model did not show reliable source regions.Peer Reviewe
