PARENT SESSION
IP09 - Uncertainties in Life-Cycle and Comparative Risk Assessment
Chair: Pennington, David1, 1 GECOS-DGR, EPFL, Lausanne, Vaud, Switzerland
Co-chair: McKone, Tom 2, Jones, Kevin3, 2 University of California, Berkeley, CA3 Lancaster University, ON, LA1 4YQ
2:10 PM to 5:30 PM - Tuesday, 19 November 2002
Room Room 151 G
(IP70) Uncertainty insights from spatial versus non-spatial multimedia modelling for Western Europe.
Pennington, David*,1, Ammann, Christoph1, Pelichet, Thierry1, Margni, Manuele1, Jolliet, Olivier1, 1 Life Cycle Systems Group, EPFL, Lausanne, Switzerland
ABSTRACT- This presentation provides an overview of the uncertainties between spatial and more conventional non-spatial multimedia fate and exposure models for use in the calculation of human intake fractions in life cycle assessment (LCA) and chemical risk assessment (intake fraction - the fraction of mass of a chemical released into the environment that results in population-based human exposure). The spatial model for Western Europe consists of modules for chemical fate in each environmental medium (air, water, soil, ...) and a human exposure module. Each medium-specific fate module takes spatial variation, advective transport, intermedia exchange, and degradation processes into account. Fate processes are considered for hydrologically-defined surface water areas (watersheds), coastal waters, sediments, air zones, urban areas, soils and vegetation. The human exposure module includes consideration of the spatial variation of population density, the population supported by different water sources, and the distribution of food production. Intake fractions are calculated with and without the consideration of spatial distinctions using the same model and chemical input data. A discussion is provided of the magnitude of the differences, accounting for uncertainty, and the causes of these differences. Guidelines are suggested to help identify the relevant degree of spatial distinction for a given chemical, hence for appropriate model selection.
Key words: multimedia model, human intake fraction, uncertainty, life cycle and risk assessment