Organic content of particulate matter in the atmosphere of Ouargla city, Algeria

The particle-bound organic compounds comprising n-alkanes, n-alkanoic monoc arboxylic acids, polynuclear aromatic hydrocarbons (PAH) : and nitrated pol ynuclear aromatic hydrocarbons (NPAH) were investigated in ambient air of t he Ouargla city area (Algeria) during a short campaign performed in Novembe r 1999. The distribution profile of n-alkanes: was consistent with the petr ogenic origin of aerosols, suggesting that they were related to torching pr ocesses of crude oil refuses in the petroleum extraction field located not far from Ouargla. Instead, the: presence of n-alkanoic acids of low molecul ar weight was indicative of microbial activity experienced by the site. PAH levels were low when compared to other polluted areas. The presence of 2-n itrofluoranthene and 2-nitropyrene, which can result from in-situ nitration of fluoranthene and pyrene, was concurrent with the substantial depletion of the most reactive among PAH, suggesting that photochemical processes inf luence the composition of the Saharian atmosphere.