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WA12A Comparative Risk Studies and LCIA Toxicity Impacts
() BIOTRANSPEC-ERA: A model to estimate metal speciation-fate-bioaccumulation and toxicological hazard for LCIA.
Bhavsar, S1, Gandhi, N1, Archbold, J2, Diamond, M1, Goulet , R3, 1 University of Toronto, Toronto, ON, Canada2 CANTOX Environmental Inc., Mississauga, ON, Canada3 Environment Canada, Existing Substances Branch, Gatineau, PQ, Canada
ABSTRACT- When conducting a Life-Cycle Assessment (LCA) for metals, an important consideration is estimating the potential impact of metals released into the environment. Since Life-Cycle Impact Assessment (LCIA) aims to assess the relative or marginal impacts of activities or releases determined through the inventory stage of Life-Cycle Assessment, we require a tool that will quantify the potential toxicological hazard or possibility of an adverse health outcome, based on generic considerations. To address the need, we have developed a generic predictive model (BIOTRANSPEC-ERA) that integrates a coupled fate/TRANsport and SPECiation/complexation (TRANSPEC; Bhavsar et al. 2004) model with BIOaccumulation and Ecological Risk Assessment (ERA) modules for estimating the potential toxicological hazard posed by metals released into the environment. The model estimates the potential toxicological hazard of metals in several stages. Potential toxicological hazard to aquatic organisms is assessed from TRANSPEC results by means of comparing estimated concentrations with concentration benchmarks, where it is now possible to consider the concentration of the toxicologically relevant species. Alternatively or in conjunction with this estimate, potential toxicological hazard is estimated by incorporating the Biotic Ligand Model (BLM) rather than or in addition to a chemical speciation/complexation module. The biotic ligand model simultaneously accounts for metal distribution among all ligands, including the site of toxicity such as the gill of a fish. Another avenue to pursue is using a BIOaccumulation model that calculates dietary intake based on model estimates of species concentrations in water, sediment and prey, since this may be an important route of exposure. To address the dependence of metal speciation on ambient chemistry, and hence on fate and organism exposure, we have applied the model to a series of evaluative environments that are defined with characteristics that typify a range of environmental conditions.
Key words: metal speciation, metal fate and transport, LCIA of metals, coupled model
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