苯酚及其氯代物对大型溞的毒性效应和微观机理探讨

Investigation of toxicity mechanisms of phenol & chlorophenols to Daphnia Magna

采用静态生物急性试验的方法,研究了5种酚类化合物对大型溞的急性毒性效应,并利用正辛醇/水分配系数(Kow)对实验测得的毒性数值进行了统计分析,得到了有效的毒性估测模型。研究结果表明,大型溞的幼溞接触不同化合物的不同浓度,活动会受到抑制,甚至死亡,苯酚、4-氯酚、2,4-二氯酚、2,3,4-三氯酚和五氯酚的48hEC50分别为9.15、4.64、4.40、1.92、0.37mg/L;根据化学物质对溞类的毒性评价标准,这5种化合物都属高毒物质,其中五氯酚具有极高毒性。另外,五氯酚对大型溞的致毒关键步骤不仅包括传输分配过程还有生化反应。

The acute toxicity of five phenol compounds to Daphnia magna was studied,and safety assessment was also made in the aquatic ecosystem. Combined with the data using the octanol-water partition coefficient （Kow）, an effective model was deduced to evaluate the cytotoxicity of these chemicals. Furthermore, the relationship between the structures of phenol chemicals and their cytotoxicity was proposed. It also came to that the tested chemicals remarkably restrained the mobilization of D. rnagna ,which may cause them death. EC50 （48 h） values of phenol,4-chlo- rophenol,2,4-dichlorophenol, 2,3,4-trichlorophenol and pentachlorophenol for D. rnagna were 9. 15,4. 64,4. 40, 1.92,0.37 mg/L,respeetively. In addition, the results showed that to D. rnagna the chemicals were the pollutants with high toxicity based on these EC50 values,in which pentachlorophenol had the highest toxicity. These results established a good experimental base both for developing the comparative evaluation of toxicity of phenols and for elucidating the toxicity mechanisms of them.