title: Accounting for the dissociating properties of organic chemicals in LCIA: an uncertainty analysis applied to micropollutants in the assessment of freshwater ecotoxicity.
abstract: In life cycle impact assessment (LCIA) models, the sorption of the ionic fraction of dissociating organic chemicals is not adequately modeled because conventional non-polar partitioning models are applied. Therefore, high uncertainties are expected when modeling the mobility, as well as the bioavailability for uptake by exposed biota and degradation, of dissociating organic chemicals. Alternative regressions that account for the ionized fraction of a molecule to estimate fate parameters were applied to the USEtox model. The most sensitive model parameters in the estimation of ecotoxicological characterization factors (CFs) of micropollutants were evaluated by Monte Carlo analysis in both the default USEtox model and the alternative approach. Negligible differences of CFs values and 95% confidence limits between the two approaches were estimated for direct emissions to the freshwater compartment; however the default USEtox model overestimates CFs and the 95% confidence limits of basic compounds up to three orders and four orders of magnitude, respectively, relatively to the alternative approach for emissions to the agricultural soil compartment. For three emission scenarios, LCIA results show that the default USEtox model overestimates freshwater ecotoxicity impacts for the emission scenarios to agricultural soil by one order of magnitude, and larger confidence limits were estimated, relatively to the alternative approach.
authors: SosteniPrA (UAB-IRTA-Inèdit), Institut de Ciència i Tecnologia Ambientals (ICTA), Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Barcelona, Spain. sergioalberto.cruzmonteiro@uab.cat
authors: Sérgio Alberto
authors: SA
authors: Morais
authors: Cristina
authors: C
authors: Delerue-Matos
authors: Xavier
authors: X
authors: Gabarrell
mesh_terms: D000818:Animals; D055669:Ecological and Environmental Phenomena; D005399:Fishes; D005618:Fresh Water; D008962:Models, Theoretical; D009010:Monte Carlo Method; D009930:Organic Chemicals / Q000633:toxicity*; D018570:Risk Assessment; D035501:Uncertainty; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D009930:Organic Chemicals; D062065:Wastewater; D014874:Water Pollutants, Chemical