Cu^(2+)、Zn^(2+)和Cd^(2+)对蟾蜍蝌蚪的联合毒性

Joint Toxicity of Cu^(2+),Zn^(2+)and Cd^(2+) to Tadpole of Bufo bufo gargarizans

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.

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