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1H c (1) - Pharmaceuticals (WE6/15) Charaterizing an emerging environmental issues: Probabilistic risk assessment of the acute toxicity of pharmaceuticals present in water in the European Union and North America to fish, daphnids and algae by ECOSAR screening. Sanderson, Hans1, Brain, Richard 1, Wilson, Christian1, Johnson, David1, Solomon, Keith1, 1 Centre for Toxicology, University of Guelph, Guelph, Ontario, Canada ABSTRACT- Continued exponential growth in the human population and shifts in demographic structure in western countries, combined with the increasing wastewater production, use of sewage sludge and manure on agricultural farmland and the occurrence of pharmaceuticals and metabolites in the environment are connected issues. In Europe, analyses on pharmaceutical residuals in the environment have been performed for the past decade. The first nationwide survey reconnaissance of the occurrence of pharmaceuticals in water resources in the United States was published 2002. However, the risks associated with occurrence of pharmaceuticals in water resources are widely unknown. The ecotoxicological scale, characteristics and thus required analyses, administration and regulation of this emerging environmental concern is also widely unknown. The aim of this presentation is to characterize this issue in its ecotoxicological context. Hence, in the absence of toxicological data, we scanned all the compounds observed in the environment for toxicological properties by Structure Activity Relationship (SAR) analyses using software provided by the Syracuse Research Corporation for preliminary hazard assessment. These results should eventually be tested by experimentally assessed effect concentrations. The results of the probabilistic distribution of environmental and effect concentrations do not indicate significant acute risks. The distribution of hazard quotients were all les > 1 (median 10-5). However, eight percent of the scanned compounds fulfilled both the risk characteristics criteria in terms of high log Kow (> 3) and measured environmental concentrations > 1 mg L-1. The long-term effects of subtle and chronic changes, mixtures, additive or synergistic effects and effects on other endpoints e.g. bacteria resistance, reproduction, metabolism, behavior etc. are still uncertain. This preliminary probabilistic hazard SAR screening indicates that the ecotoxicological focus and regulation on pharmaceuticals is substation ally different from traditional risks from pesticides and other chemicals. There is a need for tailored environmental approach for dealing with pharmaceuticals. Key words: Probabilistic risk assessment, ECOSAR, Hazard qoutients, Charateristics |
