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2A - Mixture toxicity (MOP/69) Quantification of Total Body Residues for the prediction of ecotoxicity of chemical effluents. Sherren, Andrew1, Eadsforth, Charles 1, Boillot, Nicolas1, Worden, Joy1, 1 Shell Research Ltd., Chester, Cheshire, UK ABSTRACT- Lipophilic solid phase samplers were placed for up to 28 days in complex refinery and petrochemical effluents in order to simulate the uptake of organic contaminants into aquatic organisms. Uptake was quantified by the parameter Total Body Residue (TBR), which can be defined as the total molar concentration of organic compounds that can be absorbed by an organism when exposed to complex organic mixtures. Toxicity tests with Microtox (Vibrio fischeri) and Daphnia magna were conducted on the same process effluents at the start of the exposure period. The relationship between TBR and toxicity was then investigated to determine whether the measurement of TBRs may be used to predict the toxicity of complex effluents. A close correlation was found between toxicity and TBR when TBR values lay within the range 10-100 mmol/kg of lipid. Effluents giving a TBR>100 mmol/kg were always very toxic to the organisms tested and effluents giving a TBR<10 mmol/kg were not acutely toxic. Such samplers have sufficient potential as a tool for predicting the ecotoxicity of chemical effluents to warrant further development. An improved technique would have a method for deploying samplers in situ to provide an integrated assessment of effluents contamination and a streamlined extraction procedure to improve cost-effectiveness. Key words: total body residues, effluents, ecotoxicity , predictive tool |
