Cu2+、Zn2+和Cd2+对蟾蜍蝌蚪的联合毒性

以蟾蜍蝌蚪为试验材料,采用联合指数相加法,研究了重金属铜(Cu)、锌(Zn)和镉(Cd)离子对蟾蜍蝌蚪的急性毒性和联合毒性效应.结果表明,Cu2 、Zn2 和Cd2 对蟾蜍蝌蚪的毒性顺序为Cu2 >Cd2 >Zn2 ,48 h的半致死浓度LC50分别为0.514、9.224、33.56 mg L-1;96 h的半致死浓度LC50分别为0.288、8.142、30.76 mg L-1.联合毒性试验结果表明,Cu2 与Zn2 及Zn2 与Cd2 共存时的联合毒性为拮抗作用;Cu2 与Cd2 共存时的联合毒性为毒性剧增的协同作用;Cu2 、Zn2 与Cd2 三者联合时的毒性为协同作用.表6参18

Joint Toxicity of Cu2+ , Zn2+ and Cd2+ to Tadpole of Bufo bufo gargarizans

The joint toxicity of copper(Cu),cadmium(Cd) and zinc(Zn) ions to tadpole of Bufo bufo gargarizans was determined using additive index method.The acute toxicities of Cu~(2 ),Zn~(2 ) and Cd~(2 ) were in the sequence of Cu~(2 )>Cd~(2 )>Zn~(2 ).The 48 h median lethal concentrations of Cu~(2 ),Cd~(2 ) and Zn~(2 ) were 0.514,9.224 and 33.56 mg L~(-1),and the 96 h median lethal concentrations of Cu~(2 ),Cd~(2 ) and Zn~(2 ) were 0.288,8.142 and 30.76 mg L~(-1),respectively.When the tadpoles were exposed to equitoxic mixtures,the results showed that the joint toxicities of Cu~(2 ) with Zn~(2 ) and Zn~(2 ) with Cd~(2 ) were antagonistic,while the joint toxicity of Cu~(2 ) with Cd~(2 ) was synergistic.The joint toxicity was synergistic when Cu~(2 ),Cd~(2 ) and Zn~(2 ) were together.Tab 6,Ref 18