Author : Alexandre Albinet
Publisher :
ISBN 13 :
Total Pages : 4 pages
Book Rating : 4.:/5 (834 download)
Book Synopsis Hydrocarbures aromatiques polycycliques et leurs dérivés nitrés et oxygénés dans l'air ambiant by : Alexandre Albinet
Download or read book Hydrocarbures aromatiques polycycliques et leurs dérivés nitrés et oxygénés dans l'air ambiant written by Alexandre Albinet and published by . This book was released on 2006 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several studies on the toxicity of the particles in the ambient air show that the polar phase, which contains the oxygenated and nitrated polycyclic aromatic hydrocarbons (OPAHs and NPAHs), is more toxic than the aromatic fraction containing the PAH. In this context, the objective of this study was to chemically characterize the NPAHs and OPAHs in ambient air on various sites (traffic, urban, suburban, rural and altitude). Samplings were performed within the framework of the French research program POllution des Vallées Alpines (POVA) during the winter 2002-2003 and the summer 2003 and in the area of Marseilles in summer 2004. Both, ambient air particulate and gas phases were sampled and particle size distribution was also studied. The results obtained on the OPAHs and the NPAHs contribute to increase the data base even still limited on these compounds. First, we developed a routine analytical method for the simultaneous quantitative determination of NPAHs and OPAHs in complex environmental matrices, using GC/NICI-MS. Results from the field campaigns show that, OPAH concentration levels were of the same order of magnitude as PAHs while NPAH concentrations were one to two orders of magnitude lower. Carcinogenic risk was estimated using toxic equivalent factors. NPAHs could contribute to 20% of the total risk. Study of source specific ratios clearly showed these compounds have a primary origin at the sites close to the sources of pollution whereas production of secondary NPAHs by gas phase reactions was prevalent at the rural sites far to the direct sources of pollution and initiated by OH (day-time reactions). The study of NPAH and OPAH sources suggested that gasoline engines were an important source of such compounds. The OPAH 9,10-anthraquinone presents a double origin: primary diesel emission and photochemical processes without to be able to discriminate when the formation occurred (before or during the sampling). The fraction of PAHs, OPAHs and NPAHs associated with the particle phase was strongly depending on their vapour pressure and the ambient temperature. Sources of these compounds take a part in their gas/particle partitioning which can bring information on their primary or secondary origin. Finally, during both, the winter and summer period, PAHs, OPAHs and NPAHs were mainly associated (>80%) with fine particles (Dp