Alternative Assays for Routine Toxicity Assessments : a Review
Abstract : The number of available aquatic toxicity tests is large and increases every year. For certain types of applications such as the routine screening of large numbers of environmental samples, standard conventional tests may be perceived as being unpractical. This has lead to the development of a (increasing) number of alternative small-scale toxicity tests also called microbiotests. The present paper reviews the potential use and limitations of a number of these alternative assays. For bacteria, algae and invertebrates, a brief description of conventional assays is given followed by an analysis of the sensitivity, reproducibility, cost-efficiency and apllication potential of freshwater microbiotests. In addition, several of case studies are discussed is which alternative toxicity tests were evaluated as routine environmental monitoring tools.
From this review it can be concluded that microbiotests have an important role to play in the screening and ranking of the hazards of chemicals and environmental wastes. However, except for a few bacterial and invertebrates tests, there is a lack of published information on the various aspects of test development and especially on the application of these alternative assays. For most microbiotests, further research and test evaluation is needed before these methods will gain widespread acceptance as valid alternatives to currently use ‘conventional’ test procedures routine environmental monitoring.