环境因子影响三氯生对蝌蚪毒性作用研究

Influence Analysis of Environmental Factors on Toxicity of Triclosan to Tadpole

针对环境中残留的医药品在不同条件下对水生环境生物的毒性变化,选取水体pH值、水温、紫外线照射3种环境因子为评价因子,分别研究三氯生对环境生物东北林蛙幼体蝌蚪的急性毒性作用。结果显示,温度升高时,源于药物毒理动力学的改变和试验生物新陈代谢的加速,三氯生对蝌蚪毒性增大;由于在酸性条件下,不带电的分子态三氯生百分比相对碱性条件下更高,更易透过生物膜,继而产生生物毒性,导致在较低pH条件下三氯生毒性较大;在紫外线照射条件下三氯生对蝌蚪的LC50较避光条件下有明显降低,表明在紫外线下三氯生光降解产物较母体毒性高。

The toxicity of chemicals may different form the change of their environmental expo- sure conditions. Therefore, under the circumstances of constantly global environmental changes, it is very necessary to re - evaluate the toxicity of pharmaceutical residues in the environment. Triclosan, as a broad- spectrum antimicrobial agent which is widely used in personal care and hygiene products, has shown significant toxicity to organisms in the study, three environmental factors including water pH, temperature, aquatic environment. In this and U~ irradiation were se- lected as the evaluation factors to investigate the effect of acute toxicity of triclosan on tadpoles of Northeast Rana chensinensis. The results demonstrated that when temperature increased, due to the change of drug toxico - kinetic and the acceleration of metabolism of the test organisms, the toxicity of triclosan on tadpoles increased. Under acidic conditions, because the percentage of unionized triclosan molecules was higher than that in basic conditions, triclosan molecules could easily go through biological membrane which would produce toxicity; as a result, the toxicity of triclosan was even higher at low pH. It was also observed that the LD50 of tadpoles was de- creased dramatically under UV irradiation compared to bank samples, which indicated that toxic- ity of degradation products of triclosan was greater than that of the parent compound under UV light. To investigate the toxicity change in various environmental conditions is really of great sig- nificance for the safety control of pharmaceutical chemicals.