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(444) An ecological approach to QSAR-modelling of the toxicity of alkylated phenols and polycyclic aromatic hydrocarbons. Smith Varskog, Anita1, Gundersen, Jorunn2, Utvik, Toril3, 1 2 3 ABSTRACT- Most existing QSAR-models are valid in relatively narrow environmental domains, commonly restricted to a relatively small set of chemicals, one biological species, one lifestage, one type of biological endpoint, a fixed exposure time, and relatively constant environmental conditions (e.g. temperature and salinity). This presentation gives an example of how QSAR-methodology can be applied to develop models that are valid within a larger environmental domain, and at more environmental realistic conditions than most existing QSAR-models. QSAR-models have been developed for alkylated phenols (1.46 < log Pow < 3.65) and polycyclic aromatic hydrocarbons (3.35 < log Pow < 6.35). Prediction of toxic levels (EC/LC50-values in mmol/L) can be made for three trophic levels (algae, crustacean and fish), three different biological endpoint categories (mortality, growth, and reproduction) and for varying exposure time, temperature and salinity. This can be applied to predict more realistic PNECs (Predicted No Effects Concentrations) to be used for environmental risk assessments. However, ecological relevance is gained at the expense of accurate predictions of toxic levels for single aquatic species. The project has been a part of the project DREAM (Dose-related Risk and Effect Assessment Model), with the participants Statoil, Norsk Hydro, Elf Petroleum, Agip, Akvamiljo, Sintef and TNO. Key words: QSAR, aquatic environment, alkylated phenols, PAHs |
