Volatility analysis is a method that makes use of different volatilisation temperatures of chemical compounds, thereby separating volatile compounds, such as.
Cite abstract as Author(s) (2007), Title, European Aerosol Conference 2007, Salzburg, Abstract T13A038
Urban particle number size distributions of ambient-state and non-volatile aerosols in Augsburg, Germany K. Heinke1, W. Birmili1, A. Wiedensohler1, M. Pitz2,3, J. Cyrys2,3, and A. Peters2 1
Leibniz Institute for Tropospheric Research, 04318 Leipzig, Germany 2 GSF National Research Center for Environment and Health, Institute of Epidemiology, 85758 Neuherberg/Munich, Germany 3 WZU - Environmental Science Center of the University Augsburg, 86159 Augsburg, Germany Keywords: aerosol size distribution, urban aerosols, soot particles
We will present a statistical summary of the 2year data set, including an analysis of the relationship between total and non-volatile particle size distributions, and the meteorological factors that cause high concentrations of total and non-volatile particle fractions, such as wind direction, mixed layer height, and remote transport.
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Fine and ultrafine (< 100 nm) aerosol particles in the environment have moved into the interest of public health research due to their presumed adverse effects upon human health, such as cardiovascular and respiratory disease. While the adverse effects of ambient particles are in general widely acknowledged, there has been only little epidemiological evidence on the role of particular sub-fractions of the aerosol. The city of Augsburg in Southern Germany hosts a centre of environmental medical research for the quantification of air pollutants and their effects on sensitive parts of the population (KORA; Holle et al. 2005). Specialized aerosol particle measurements were started in November 2004 in order to support future epidemiological studies within KORA. As ambient particles are a complex mixture of a myriad of chemical compounds, there is a growing need to characterise and isolate those particular subfractions that are relevant to human health. Volatility analysis is a method that makes use of different volatilisation temperatures of chemical compounds, thereby separating volatile compounds, such as organic matter, sulfates and nitrates, from nonvolatile compounds, such as soot and mineral dust. A volatilisation temperature of 300°C allows to identify soot particles in the ultrafine size range emitted from vehicular traffic (Wehner at al., 2004; Rose et al. 2006). At the GSF research station Augsburg ambient state and non-volatile particle size distributions (3- 800 nm) have been measured continuously since 11/2004 using a twin differential mobility particle sizer (TDMPS). Figure 1 presents median particle number size distribution for ambient and non-volatile compounds during the rush hour traffic; while the ambient particle number distribution peaks in the Aitken mode (~40 nm), the curve of non-volatile residues peaks in the nucleation mode (~10 nm) and in lessvolatile particle mode (~80 nm) which presents the externally mixed population of soot particles. These measurements imply that within the measurement accuracy, every ambient particle contains a nonvolatile core. The chemical composition of the nonvolatile residues < 20 nm is, however, not known yet.
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Figure 1: Median particle number size distribution of total (grey) and non-volatile (black) aerosol between 7:00 – 9:00 am.
Holle, R., Happich, M., Löwel, H., Wichmann, H. E. (2005): KORA – A Research platform for population based health research, Gesundheitswesen 2005, 67 Sonderheft 1, S19-S25. Wehner, B., Philippin, S., Wiedensohler, A., Scheer, V., Vogt, R. (2004): Variability of nonvolatile fractions of atmospheric aerosol particles with traffic influence, Atmos. Env., 38, 6081-6090. Rose, D., Wehner, B., Ketzel, M., Engler, C., Voigtländer, J., Tuch, T., Wiedensohler, A. (2006): Atmospheric number size distributions of soot particles and estimation of emission factors, Atmos. Chem. Phys., 6, 1021-1031.
