From microbiotest to decision support system: an assessment framework for surface water toxicity

A decision framework for the site-specific detection of toxic effects of contaminants in surface waters is presented. Although the main objective of the development of this framework aimed at supporting water quality boards in their studies on polluted waters and sediments, it could also be of wider use. The decision framework is illustrated by means of a case study on a ditch that is contaminated with heavy metals. From this study it appears that the designed framework considerably facilitates the choices to be made in the assessment of surface water toxicity. It also illustrates that biological techniques provide additional information on the biological availability and combined toxicity of all the contaminants present and not only of those which have been analyzed by chemical methods.