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(M/EH064) Testing biodegradability and bacterial toxicity of pharmaceuticals in standardized methods - is there a conceptual problem? Ingerslev, Flemming1, Unger, Jörg2, Wiethan, Jürgen 2, Halling-Sørensen, Bent1, Kümmerer, Klaus 2, 1 2 ABSTRACT- Biodegradability and ecotoxicity are important properties characterizing a chemical compound in environmental risk assessment. A battery of standardized methods exists for testing industrial chemicals and pesticides. These methods are using mixed cultures of bacteria from activated sludge or other relevant environments. Recently a new class of pollutants namely the pharmaceuticals has been identified. The biodegradability and bacterial toxicity of these substances has been screened using existing standardized methods. In comparison with other environmental chemicals, medical compounds (e.g. antibiotics) have very specific modes of action. They may therefore have impact on only a few bacterial species in a mixed bacterial population. This may lead to drastic changes in the dynamics of the bacterial population in such mixed bacterial cultures. Certain organisms may be sensitive to the antibiotic whereas other bacteria are unaffected. The result could be that the sensitive organisms are removed from the system while other species benefits by the absence of other bacteria. Current study discusses how these changes may have impact on the behavior of the whole system and therefore have impact on the test results. Key words: Biodegradation, Standard tests, Pharmaceuticals, bacterial toxicity |
