Pb2+、Cd2+对3种水生动物致毒效应影响的比较研究

在特定时间（12、24、48、72h）内,研究了Pb^2＋和Cd^2＋对草履虫（Paramecium caudatum）、三角涡虫（Dugesia japonica）和中华圆田螺（Cipangopaludia viviparrus）3种水生动物的单一和联合毒性效应.结果表明：在同等条件下,Cd^2＋对三者的致毒效应都明显强于Pb^2＋;3种动物中,草履虫最敏感,而圆田螺耐受能力最强;随单一毒物浓度的增大以及暴露时间的延长,两者的致毒效应都显著增大,表现出明显的浓度—效应和时间—效应关系;二者复合作用时,对3种动物的致毒效应主要表现为与二组分的浓度比例有关.复合致毒效应也表现出了明显的浓度—效应关系,并且浓度和暴露时间的交互作用对3种水生动物毒性都有显著的影响.

The Toxic Effects of Pb2+ and Cd2+ Pollutants on Three Kinds of Aquatic Organisms

The single and combined toxicity effects on Paramecium caudatum,Dugesia japonica and Cipangopaludia cathayensis exposed for special period(12,24,48 and 72 h) in different Pb2+ and Cd2+ concentrations were studied by using toxic experiment techniques.The results showed:for the toxicity of two kinds of pollutants,the Cd2+ is more poisonous than the Pb2+. For the sensitivity to the pollutants,the P.caudatum,C. cathayensi and D. japonica increase evidently in turn.The statistical analyses indicated that the single and combined toxicity effects both increase with the exposed time extended,especially for the combined toxicity(P < 0.05),showing a marked time-effect relation. As for the single effect,it increase prominently with Pb2+ and Cd2+ concentrations(P < 0.05);But in the case of binary effect,the results showed obviously a time-effect(P < 0.01) as well as a concentraction-effect relations. In addition,there also existed remarkabce correlations between the proportion of the pollutants and the exposed time on the three kinds of aquatic organisms (P < 0.01).