Annual variation of particulate organic compounds in PM10 in the urban atmosphere of Algiers

Measurements of the principle solvent extractable organic components associated with airborne particulates were conducted at two urban sites of Algiers, Algeria, between July 2005 and June 2006 to gain information about their ambient concentration levels and source impacts. The compounds identified included n-alkanes, n-alkanoic mono- and dicarboxylic acids, polycyclic aromatic hydrocarbons (PAHs), nitrated-PAHs (N-PAHs), and nitrogen/oxygen containing polycyclic aromatic compounds (PACs). The seasonal average concentrations for these chemical groups ranged from 42–193 ng m− 3, 292–2656 ng m− 3, 8–629 ng m− 3, 12–189 pg m− 3, and 2–9 ng m− 3, respectively. Maximum concentrations were recorded during the cold season for all groups except N-PAHs that peaked in summertime. Fatty acids accounted for more than 67% of total organic aerosol mass at both sites. The ratios between atmospheric concentrations of marker species as well as the evolution of the distribution of species in the chemical groups studied indicate that the organic aerosols are of vehicular origin.