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(83-04) Classical and multivariate QSARs for the toxicity of oil-tar components in terrestrial ecosystems. Thomsen, Marianne*,1, Scott-Fordsmand, Janeck1, Fauser, Patrik1, 1 National Environmental Research Institute, Roskilde, Denmark ABSTRACT- Polycyclic aromatic hydrocarbons (PAHs) are common environmental pollutants of special concern for many contaminated areas. Ecotoxicological experiments for the elucidation of the hazard potential of selected oil-tar constituents have been performed. The test organisms included some of the most common test species including plants and soil organisms. Besides the PAHs, the study also includes a number of N, S, and O-heteroatom analogues of the PAHs. A first approach developing multivariate oil-tar component QSARs for assessing terrestrial ecosystems are presented based on the mortality and reproduction endpoints. Conventional QSARs based on simple linear regression models are used for initial screening of the hazard potential of PAHs towards different specie types. The predictive ability of the conventional QSAR models are compared to multivariate QSARs based on three-dimensional quantum-chemical and semi-empirical descriptors. The multivariate QSAR models are used for exploring latent structural and electronic parameters explaining the toxic potential of the individual PAHs. Furthermore an evaluation of the significant parameters for explaining possible cause-related mechanisms, as well as species sensitivity analysis, is presented. Key words: QSAR, PAH, Toxicity, Terrestrial environment |
