Ambient air pollution by aromatic hydrocarbons in Algiers

The analysis of the C6–C16 semi-volatile organic compounds reveals the presence of numerous aromatic hydrocarbons in the ambient air of Algiers. Three representative sites were chosen for sample collection at roadside, urban background and semi-rural areas. The following major monocyclic aromatic hydrocarbons were found: benzene, toluene, ethylbenzene, (m, p)- and o-xylene, also referred to as BTEX. Near the road traffic, benzene and toluene mean concentrations were 27 and 39 μg m−3, respectively, with benzene concentration values higher than 40 μg m−3 often observed. At the urban site, the benzene concentration often exceeds the European regulatory limit of 10 μg m−3 while the compositional ratios of toluene to benzene and (m–p) xylene to ethylbenzene are within the typical range of values observed in urban atmospheres worldwide. The seasonal variation indicates a decrease in concentration during summer of the reactive o-xylene compound. It is suggested that Algiers’ source of high-level air pollution by aromatic hydrocarbons is related to car traffic emissions.