Atmospheric Chemistry and Physics Polycyclic aromatic hydrocarbons (PAHs) in the atmospheres of two French alpine valleys: sources and temporal patterns

Abstract. Alpine valleys represent some of the most impor-tant crossroads for international heavy-duty traffic in Europe, but the full impact of this traffic on air quality is not known due to a lack of data concerning these complex systems. As part of the program “Pollution des Vallées Alpines ” (POVA), we performed two sampling surveys of polycyclic aromatic hydrocarbons (PAHs) in two sensitive valleys: the Chamonix and Maurienne Valleys, between France and Italy. Sampling campaigns were performed during the summer of 2000 and the winter of 2001, with both periods taking place during the closure of the “Tunnel du Mont-Blanc”. The first objec-tive of this paper is to describe the relations between PAH concentrations, external parameters (sampling site localiza-tion, meteorological parameters, sources), and aerosol char-acteristics, including its carbonaceous fraction (OC and EC)