Study on Fate and Ecotoxicity Evaluation of Hard-decompositive Toxic Chemicals in Ecosystems

点击翻译按钮获取中文摘要

Pullution of ecosystems by dioxine, agricultural chemicals etc. has become recognized to be an global and very serious issues on a matter of life or death of mankind.The object of this study is to analyze the fate and to evaluate ecotoxicity toxic chemicals released into environments. We clarified the origin of toxic chemicals, the fate of chemicals in an aquatic ecosystem, ecotoxicity, antifouling chemicals in the Inland Sea of Seto and interaction effects of chemicals.At first, we took up the landfill leachate of industrial wastes and evaluated cytotoxicity, genetic toxicity, endocrine disruption. Cytotoxicity for swimming inhibition of Daphnia magna was determined for all sampling cites of leachates. We determined genetic toxicity from a few sampling cites. However, endocrine disrupting effect was determined from 40 fold concentrated leachates of almost all sites. We examined the fate of toxic organic-chemicals along a river in Okayama Prefecture. Hard-dissolved chemicals by water w … More as adsorbed to river sediments and existed more in sediments than in water. Therefore, the toxicity of sediments was stronger than that of water.The quantitative structure-activity relationship analysis was performed for 13 kinds of Chlorophenols using Saccharomyces cerevisiae. The relationships were established between EC50's and a number of molecular proparties. When molecular parameters were used alone, there were high correlations for octanol-water partition coefficient, These results showed that QSAR is a very effective tool in predicting the toxicity of chlorophenols to Saccharomyces cerevisiae as well as to other organisms. Interactive effects among heavy metals and agricultural chemicals, Imidacloprid, were investigated using Daphnia magna. Synergistic and antagonistic effects were observed for heavy metals. Antagonistic and additive effects were observed for Imidacloprid and heavy metals. We could get a high correlation between a traditional swimming inhibition test and a newly developed mobility inhibition test using D. magna. Recently a new antifouling agent Irgarol 1051 has been used. It was found that the Inland Sea of Seto has already been polluted by the new antifouling agent. The decomposed chemicals M1 of irgarol 1051 was also determined in the sea water. The toxicity of the daughter chemicals was weaker than the parent chemicals, but it had hard disintegration. It suggested that the daughter chemicals M1 should be taken care for environmental pollution of sea water in the long run. Less