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4C - Combined effects of contaminants and environmental stressors (MOP/182) ACE - Analysing combination effects of mixtures of estrogenic chemicals in marine and freshwater organisms. Harris, Catherine1, Consortium, the ACE, 1 Brunel University, Uxbridge, Middlesex, UK ABSTRACT- Increasing numbers of chemicals are being found to possess endocrine disrupting properties. Concern is growing that such chemicals may be capable of disturbing reproductive function in wildlife. Although significant numbers of studies have attempted to address this issue, the majority of data published thus far have emanated from studies conducted using single chemicals. In reality, wildlife are exposed to ill-defined mixtures of large numbers of chemicals throughout their lifetime. The objective of ACE is to contribute to the hazard assessment of endocrine disrupting chemicals in the aquatic environment by assessing the effects of mixtures of estrogenic chemicals on fish, as well as in a number of in vitro assays. The observed effects will be compared to the effects predicted by the model of Concentration Addition, in order to establish whether such a model might be used in future risk assessment practices. In addition, data from the in vitro assays will be compared to those of the in vivo assays, as an indication of whether effects in fish can be predicted by studies conducted in rapid, inexpensive cell-based assays (thus reducing the need for in vivo trials in such situations). Analytical chemistry support will be provided throughout the project. For this, existing methods will be optimised to allow analyses of extremely low concentrations of environmental estrogens (representative of the concentrations found in surface waters). In addition, methods will be developed for the simultaneous analysis of mixtures of estrogenic compounds in water samples. On completion of the project, we hope to have an improved understanding of the relevance of current environmental guidelines (based on single chemical effects), and the importance of accounting for joint effects of endocrine disrupters. Key words: estrogen, mixtures, fish, in vitro |
