Case study analysis of PM burden at an urban and a rural site during the AUPHEP project

On several days during the 1 year measurement period the 24 h average EU concentration limit for PM10 of 50 mug m(-3) was exceeded at the urban site AUPHEP1 as well as at the rural site AUPHEP2. The exceedances occurred generally during the winter half-year, however, during the summer period the elevated values were recorded as well. At the urban site several days with concentrations above 70 mug m(-3) were observed. The highest 24-h concentration reached 130 mug m(-3) on 1 January 2000. Regional transport processes of polluted air mass were the influencing factor for the elevated PM burden at both sites, however, the rural site was often additionally polluted by the Vienna metropolitan area. The high pollution events generally occurred under weather condition with prevailing SE-SW air flow. The chemical composition of the PM fractions during "high PM" was clearly different than that during the days with "low PM" burden. The chemical composition obviously reflects different source regions, paths of the air masses as well as weather patterns. (C) 2004 Elsevier Ltd. All rights reserved.