Seasonal and diurnal variations of atmospheric PAH concentrations between rural, suburban and urban areas

Atmospheric sampling (gas and particle‐phases) of 17 polycyclic aromatic hydrocarbons (PAHs) were performed between 2002 and 2004 in Strasbourg (east of France) and its vicinity. Sites were chosen to be representative of urban (Strasbourg), suburban (Schiltigheim) and rural (Erstein) conditions. Field campaigns were undertaken simultaneously in urban/suburban and urban/rural sites during three seasons. Moreover, air sampling has been performed in three 4–h time intervals per day (morning, midday/afternoon, and evening) to assess the diurnal variations in PAH concentrations.Mean total PAH concentrations were 92 ng m‐3 for the rural site, 127 ng m‐3 for the urban site and 149 ng m‐3 for the suburban site. There is a significant difference in concentrations between the three sites, independently of the seasons considered. At the three sites, the most abundant compounds determined were naphthalene followed by phenanthrene and acenaphtene. Moreover, a variation between warm period (spring) and cold period (autumn and winter) for the three sites was observed with higher PAH concentrations during the cold periods.The diurnal variations of PAH concentrations at the three sites, in warm period, have been observed in accordance with the intensity of the vehicle traffic, with highest concentrations during the morning and the evening. In cold period, there was no difference in concentrations between these two time intervals of high vehicle traffic in urban and suburban sites. It seems that the contribution of domestic heating influenced the diurnal variations of some compounds, especially in the rural site.