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(191) Modelling Continental Scale Contaminant Fate: Development and Application of Linked Regional Contaminant Fate Models. MacLeod, Matthew1, Woodfine, David1, Mackay, Don1, Sweetman, Andy2, Jones, Kevin2, 1 2 ABSTRACT- Contaminant fate modelling in sensitive ecosystems such as the Great Lakes Basin and the Canadian Arctic has shown that distant sources of chemical emissions may have impacts on regional environments. Quantitative assessment of the impact of chemical emissions on remote and sensitive areas therefore requires a large spatial scale model of interconnected regional environments. A national scale model based on the ChemCAN framework and consisting of 24 linked regional segments has been developed to describe contaminant migration within Canada. The model has been adapted and extended to encompass the entire North American continent. These models track the flow of air, water and contaminant between connected regions, and can provide a quantitative link between emissions and the observed continental background concentration of contaminants. Application of the models in steady-state form is illustrated for two chemicals: the current use pesticide lindane and the volatile chlorinated solvent trichloroethylene. The result of this modelling exercise is a detailed mass balance for these chemicals on a continental scale, which provides a quantitative link between emissions and concentrations that are measured in remote areas. A linked regional model for the European continent based on similar modelling principles that is under development at Lancaster University will also be described. Key words: Long Range Transport, Model, Continent Scale, POPs |
