Bioaccumulation of environmental organic pollutants in freshwater organisms - Biotransformation and its significance
Bioaccumulation, as a consequence of
interaction between organism and contaminants, is an unfavorable symptom for
individual organism or/and its population in view of ecotoxicology. As the
contaminants are accumulated, they are partly biologically transformed and then
excreted. This process leads to lower bioaccumulation and less toxicity in most
cases. Due to lack of data on biotransformation products (BTPs) and their
contributions to bioaccumulation in aquatic organisms, the entire processes of
bioaccumulation possibly explaining chemical fate and toxicity is still not
well understood. Fortunately, with highly developed analytical tools, i.e. high
resolution mass spectrometry, it becomes feasible to identify BTPs and track
their pathways through biological processes responding to chemical exposure. Information
about BTPs can be applicable to assess ecotoxicological risks posed on aquatic
organisms accumulating environmental pollutants. In addition rules governing
biotransformation can be developed and feed into appropriate predictive models.
The goal
of the present study is to estimate bioaccumulation factors of selected
environmental organic pollutants for freshwater organisms, e.g., Daphnia magna, Gammarus pulex, to
identify BTPs and their major pathways, and to evaluate contribution of
biotransformation to overall bioaccumulation.
Funding:
Swiss National Science foundation, Eawag
Publications:
Jeon, J., D. Kurth, J. Hollender. 2013. Biotransformation pathways of biocides and pharmaceuticals in freshwater crustaceans based on structure elucidation of metabolites using high resolution mass spectrometry, Chem. Res. Toxicol. 266: 313-324.
Kretschmann, A., R. Ashauer, J. Hollender, B. Escher. 2012. Toxicokinetic and Toxikodynamic Model for Diazinon Toxicity – Mechanistic Explanation of Differences in the Sensitivity of Daphnia magna and Gammarus pulex, Environ. Toxicol. Chem. 31: 2014–2022.
Kretschmann, A., R. Ashauer, K. Hitzfeld, P. Spaak, J. Hollender, B. Escher. 2011. Mechanistic Toxicodynamic Model for Receptor-mediated Toxicity of Diazoxon, the Active Metabolite of Diazinon, in Daphnia magna, Environ. Sci. Technol. 45: 4980-4987.
Kretschmann, A., R. Ashauer, T. Preuss, P. Spaak, B. Escher, J. Hollender. 2011. Toxicokinetic Model Describing Bioconcentration and Biotransformation of Diazinon in Daphnia magna, Environ. Sci Technol. 45:.4995-5002. (awarded by German Chemical Society (GDCh), Division Environmental Chemistry and Ecotoxicology)