Ecotoxicity | Ecotoxicité

[Departement_IRSTEA]Ecotechnologies [TR1_IRSTEA]INSPIRE

English. Ecotoxicity impact assessment of chemicals in life cycle assessment (LCA) adheres to a number of underlying principles and boundary conditions: 1) a large number of emitted substances to cover (at least 100,000 potentially relevant elementary flows with current models covering around 2500), 2) linearity of characterisation models, 3) conservation of mass and mass balance, 4) infinite time horizon, 5) additivity of toxicity, 6) assuming average conditions as best estimates to avoid bias in the comparison (including consideration of generic/average ecosystems and impacts). The cause-effect mechanism for ecotoxicity impacts of chemicals can be divided into four parts: 1) chemical fate (i.e. chemical behaviour/distribution in the environment), 2) exposure (i.e. bioavailability), 3) effects (i.e. affected species), and 4) severity (i.e. disappeared species). In terms of species represented, a freshwater ecosystem is described in this chapter by three trophic levels: 1) primary producers (e.g. algae), 2) primary consumers (i.e. invertebrates), and 3) secondary consumers (e.g. fish). Model uncertainty was estimated at about three orders of magnitude on top of important sources of parameter uncertainty such as degradation rates and effect factors. Current midpoint LCIA methodologies covering ecotoxicity include TRACI 2.0, and the ILCD recommended methodology, both employing the USEtox factors. Current LCIA methodologies covering midpoint and endpoint characterisation are ReCiPe, LIME, IMPACT 2002+, and IMPACT World+. Important research needs are 1) increasing substance coverage, 2) further developing marine and terrestrial ecotoxicity modelling for midpoint, 3) improving endpoint modelling for ecotoxicity towards biodiversity, 4) consideration of long-term emissions and impacts of metals, 5) importance of spatial and temporal variability, 6) mixture toxicity, and 7) decreasing model and parameter uncertainty.