重金属铜、铅、锌对尾草履虫的联合毒性

Joint Toxicity of Copper, Lead and Zinc to Paramecium caudatum

为了解重金属混合物对尾草履虫(Paramecium caudatum)的联合毒性,本研究采用急性静水式生物测试法,以12 h的半致死浓度(lethal concentration 50,LC_(50))作为毒性评价标准,运用水生毒理联合效应相加指数法对重金属的联合毒性进行评价,测试了铜离子(Cu^(2+))、铅离子(Pb^(2+))与锌离子(Zn^(2+))对尾草履虫的联合毒性。结果表明:Cu^(2+)、Pb^(2+)与Zn^(2+)对尾草履虫单一毒性的12 h-LC_(50)分别为0.45μmol/L(0.0288 mg/L)、1.46μmol/L(0.3025 mg/L)、3.06μmol/L(0.2001 mg/L),单一毒性作用强弱关系为:Cu^(2+)>ZnCu^(2+)>Pb^(2+);Cu^(2+)/Pb^(2+)、Cu^(2+)/Zn^(2+)、Pb^(2+)/Zn^(2+)二元联合对尾草履虫的联合毒性均表现为拮抗作用。研究结果为重金属对水生物的联合毒性提供数据,也为制定水体重金属安全浓度提供参考。

In order to research the joint toxicity of heavy metal mixtures to Paramecium caudatum,acute static bioassays were conducted to determine the joint toxic effects of Cu^(2+),Pb^(2+)and Zn^(2+)on P.caudatum,the Lethal Concentration50(LC_(50))at 12 hour(h)was used as the evaluation standard of toxicity and the joint toxicity of heavy metals was evaluated by aquatic toxicology effect additive index method.Results showed that the 12 h-LC_(50)s of Cu^(2+),Pb^(2+),and Zn^(2+)on P.caudatum were 0.45μmol/L(0.0288 mg/L),1.46μmol/L(0.3025 mg/L),3.06μmol/L(0.2001 mg/L),the toxicity degree ofthree heavymetals were Cu^(2+)>Zn^(2+)>Pb^(2+),and the binarycombinations of Cu^(2+)/Pb^(2+),Cu^(2+)/Zn^(2+),Pb^(2+)/Zn^(2+)had an antagonistic toxic effect on P.caudatum.This research provides data for the research of joint toxicity of heavy metals to organisms,and also provides a reference for the set of the safe concentration of heavy metal in the water.