Comparative acute toxicity of the first 50 multicentre evaluation of in vitro cytotoxicity chemicals to aquatic non-vertebrates

The acute toxicity data of the first 50 chemicals of the Multicentre Evaluation of in-vitro Cytotoxicity (MEIC) programme are compared for 3 cyst-based toxicity tests (Artoxkit M with Artemia salina, Streptoxkit F with Streptocephalus proboscideus, and Rotoxkit F with Brachionus calyciflorus), and 2 other tests (the Daphnia magna and the Photobacterium phosphoreum Microtox tests) commonly used in ecotoxicology. The difference in sensitivity for the 50 chemicals was as high as 19 orders of magnitude (on a molecular weight basis) between the most and least sensitive species. A similar toxicity ranking of the 5 test species was found for most of the chemicals and the interspecies correlations were high. Results from principal component analysis (PCA) and cluster analysis indicated that the groupings were not related to a clear and defined chemical structure. However, the loading plot of the first 2 principal components might aid in selecting the minimal number and type of tests that had to be included in a battery which encompasses a broad spectrum of toxicity levels. The use of a selected battery of tests to evaluate ecotoxicity is supported and its possible importance for screening of biologically-active compounds from natural sources is suggested. There are 73 references.