HR: 1330h
AN: U32A-0029    [PDF]
TI: Large Scale Numerical Modelling to Study the Dispersion of Persistent Toxic Substances Over Europe
AU: * Aulinger, A
EM: aulinger@gkss.de
AF: GKSS Research Center, Institute for Coastal Research, Max-Planck-Strasse 1, Geesthacht, 21502 Germany
AU: Petersen, G
EM: petersen@gkss.de
AF: GKSS Research Center, Institute for Coastal Research, Max-Planck-Strasse 1, Geesthacht, 21502 Germany
AB: For the past two decades environmental research at the GKSS Research Centre has been concerned with airborne pollutants with adverse effects on human health. The research was mainly focused on investigating the dispersion and deposition of heavy metals like lead and mercury over Europe by means of numerical modelling frameworks. Lead, in particular, served as a model substance to study the relationship between emissions and human exposition. The major source of airborne lead in Germany was fuel combustion until the 1980ies when its use as gasoline additive declined due to political decisions. Since then, the concentration of lead in ambient air and the deposition rates decreased in the same way as the consumption of leaded fuel. These observations could further be related to the decrease of lead concentrations in human blood measured during medical studies in several German cities. Based on the experience with models for heavy metal transport and deposition we have now started to turn our research focus to organic substances, e.g. PAHs. PAHs have been recognized as significant air borne carcinogens for several decades. However, it is not yet possible to precisely quantify the risk of human exposure to those compounds. Physical and chemical data, known from literature, describing the partitioning of the compounds between particle and gas phase and their degradation in the gas phase are implemented in a tropospheric chemistry module. In this way, the fate of PAHs in the atmosphere due to different particle type and size and different meteorological conditions is tested before carrying out large-scale and long-time studies. First model runs have been carried out for Benzo(a)Pyrene as one of the principal carcinogenic PAHs. Up to now, nearly nothing is known about degradation reactions of particle bound BaP. Thus, they could not be taken into account in the model so far. On the other hand, the proportion of BaP in the gas phase has to be considered at higher ambient temperatures. The gaseous BaP is known to be subject to various degradation and metabolisation reactions caused by oxidants and sunlight. The model will be used to assess human exposure to various PAHs and their metabolites depending on different emission and weather scenarios either directly via PAHs in ambient air or by accumulation in the food chain when they are deposited over agricultural or fishing areas.
DE: 0345 Pollution--urban and regional (0305)
SC: U
MN: 2003 Fall Meeting