New Measurement Site for Physical and Chemical Particle Characterization in Augsburg, Germany

P-010 Introduction: Since 1999 epidemiological studies on short-term effects of fine and ultrafine particles were performed in a medium-sized European city. The exposure to particles was characterized by particle mass (PM2.5) and total number concentration (TNC) taken at a single monitoring station. However, measurements of such sum parameters could only crude describe the complex and dynamic urban aerosol system. Therefore since autumn 2004 we operate a new fixed monitoring site in this city for more detailed physical-chemical particle characterization. Here we describe the measurements techniques and present the results of the ambient aerosol measurements for the first year. Methods: The new monitoring site is located 2 km south of the city center in Augsburg. Besides well established measurements method for particle mass and number distribution we introduced methods for other physical properties, such as particle length, density and total active surface. We equipped the Scanning Mobility Particle Sizer system with a thermodenuder to distinguish between the volatile and non volatile part of the particle fraction. Besides the physical characterization of the ambient aerosol, we collect data on chemical composition (particulate sulfate and nitrate, Black Smoke (as a function of absorption coefficient), organic and elemental carbon mass concentration for PM2.5) on semi-continuously base. Results: The annual mean for PM2.5 was 17.4 μg/m3, for sulfate, nitrate and black carbon 2.8, 3.2 and 2.3 μg/m3, respectively. Preliminary findings reveal day-to-day and seasonable variability in aerosol mass and composition. Whereas the correlation between PM2.5 and sulfate on hourly base is rather strong (r=0.79), the correlation between PM2.5 and organic carbon is moderately (r=0.42). It indicates that the short-term variability of PM2.5 is more driven by the anorganic components than by the organic fraction. Monthly averages and diurnal patterns in aerosol number concentration, aerosol sulfate, nitrate, organic and elemental carbon will be discussed in this presentation with emphasis on the process affecting them. Discussion and Conclusions: Semi-continuously and detailed physical and chemical characterization of ambient aerosol is done only on very few other sites around the world. On the basis of the collected data we will be able to further characterization of the urban aerosol in terms of source apportionment and the daily impact of the specific particle source to the particle concentration. The measurement site will also serve as a platform for further epidemiological research with a main focus on health effects of the cardiovascular system.