A test battery for the ecotoxicological evaluation of the agri-chemical Environ

The ecotoxicological effects of the agri-chemical Environ were evaluated using a test battery comprising organisms representing three trophic levels of the aquatic ecosystem. The sensitivities of the test species to Environ were as follows: Microtox>Daphnia magna>Pseudokirchneriella subcapitata= Thamnocephalus platyurus=Oncorhynchus mykiss>Artemia salina>Tetrahymena thermophilia. An order of magnitude sensitivity between the test species was observed which emphasizes the importance of a test battery approach in the assessment of possible ecological consequences of agri-chemicals. In addition, the aquatic bioassays were found to be more sensitive (e.g., greater than three orders of magnitude for D. magna) than previously reported mammalian toxicity data for Environ. Toxicity of Environ was also investigated using fish (RTG-2) and human fibroblast cell lines (HepG2 cells) and juvenile O. mykiss. Environ was shown to have greater toxicity in the acute lethality test than with the fish cell line. However, in vivo/in vitro comparisons in this instance we feel would be premature and imprecise owing to valid concerns regarding fish loading rates for the in vivo test, and exposure duration with the in vitro test.