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6A - LCIA - Toxicity/RA (WEP/226) The toxicity of metals in the Life Cycle Impact Assessment on aquatic ecosystems. Payet, Jerome1, Birkved, Morten2, 1 Corresponding author: jerome.payet@epfl.ch - Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Ch-1015, Switzerland2 Presenting author - Technical University of Denmark, Kgs. Lyngby, Dk-2800, Denmark ABSTRACT- In Life Cycle Assessment studies including inorganic chemicals, the results are often outlining the importance of metals in terms of potential impacts, especially in aquatic environments. One of the reasons could be the overestimation of the actual toxicity of metals due to overestimation of the persistence of metals measured as the bioavailable time. Typically metals are included in the impact assessment as having either infinite or near infinite (more than 10 year) half-lives. Using models specifically designed to describe speciation of metals (PHREEQ C) and bioavailability of specific metal ions (WHAM) in standard ecotoxicity test results an estimation of the multidimensional relationship of the speciation pattern and dissolved organic matter was established. Based on the established modelled speciation pattern and bioavailability in relation to measured toxicity a comparative method, which assesses the median aquatic toxicity of metal compounds, has been developed. Copper is retained in order to illustrate the quantification of the potential impacts on the basis of the ecotoxicological tests results. Results obtained indicates that (1) metals cover a very large range of toxicity, (2) the confidence interval on the toxicity is on average twice larger for metals than for other chemicals; (3) some metals are used in pesticides, and therefore, the formulation in relation to the environmental conditions has a strong influence on the overall toxicity of the organic ion and the metal. The results are outlining the potential importance of taking speciation and bioavailability of metal species into account when evaluating their potential impacts in the aquatic ecosystems. Key words: metal toxicity, LCIA, metal species |
