Polycyclic aromatic hydrocarbons in size-segregated particulate matter from six urban sites in Europe

Polycyclic aromatic hydrocarbons (PAHs) were investigated in size-segregated particulate samples collected in a series of 7-week sampling campaigns in Europe 2002–2003. The principal objective of the study was to provide new insight into the distribution of PAHs between ultrafine, fine and coarse particle size ranges during different particulate pollution situations in Europe. The samplings were conducted in urban background sites of six cities: Duisburg, Germany (autumn), Prague, Czech Republic (winter), Amsterdam, The Netherlands (winter), Helsinki, Finland (spring), Barcelona, Spain (spring) and Athens, Greece (summer). Particulate samples were collected in 3- and 4-day periods per week using a high volume cascade impactor (HVCI). 32 PAHs were analysed from pooled samples in ultrafine (PM0.2), fine (PM0.2–2.5) and coarse (PM2.5–10) size ranges. The campaigns showed different PAH profiles, not only by concentration but also by detailed PAH composition. The PAH concentrations were high (PM10-PAH 9.9–55 ng m−3) in the autumn and winter campaigns compared to spring and summer samples (PM10-PAH 2.9–5.2 ng m−3). In Prague, the PAH contribution was the highest in PM0.2, whereas in the five other cities the PAH contribution was the highest in PM0.2–2.5. PAHs with four rings had a large contribution (41–47% of total PAH concentration in PM10) to the total PAHs in each of the campaigns. In cold-season campaigns, the contributions of the 5- and 6-ring PAHs, many of which are suspected carcinogens or genotoxic agents, became prominent in the fine (28–45%) and ultrafine (41–65%) size ranges. The representativeness of benzo[a]pyrene as a marker of total and known carcinogenic PAHs was poorer than that of benzo[k]fluoranthene.