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(190) DETERMINING PERSISTENCE AND SPATIAL RANGE OF SEMIVOLATILE ORGANIC COMPOUNDS BY GLOBAL CHEMISTRY-TRANPORT-MODELING. Lammel, Gerhard1,2, Leip, Adrian1, 1 2 ABSTRACT- Many chemicals, intentionally (such as pesticides) or unintentionally introduced into the environment are persistent or undergo long-range transport. In general, the environmental fate of xenobiotics is determined by chemical transformations in the compartments and inter-media and intra-media transports. Adequate modeling tools should include all relevant media, be geo-referenced and capable to study the fate of long-lived substances as well as substances with comparable characteristic times of transformation and transport. Global chemistry-transport-models have not been used for the description of the transport and the environmental chemistry of slowly decaying organic substances by now. We adapted a general circulation model of the atmosphere, ECHAM4, for the study of semivolatile compounds by representation of a number of inter-media exchange processes. First results show that this is a suitable tool to systematically study the influence of physico-chemical properties and time and location of introduction into the environment on the regional and global distribution of such substances. Characteristic travel distances and total residence times of pesticides studied are strongly influenced by the time and spatial patterns of application. Key words: environmental exposure, multicompartment model, persistent organic pollutants, global distribution |
