克百威、镉和铜对费氏弧菌的联合毒性效应

通过费氏弧菌急性毒性实验,研究克百威、镉(Cd)和铜(Cu)三种受试样本及其混合样本(克百威-Cd和克百威-Cu的等毒性单位比为1∶1、1∶2、2∶1,克百威-Cd-Cu的等毒性单位比为1∶1∶1、1∶1∶2、1∶2∶1、2∶1∶1)对费氏弧菌15 min和30 min的急性毒性效应,计算克百威、Cd和Cu的单一和混合样本的半数效应浓度(Median effective concentration,EC50)。克百威、Cd和Cu暴露15 min的EC50值分别为101.29、13.11、47.06 mg·L~(-1),暴露30 min的EC50值分别为107.88、11.17、39.73 mg·L~(-1)。利用毒性单位(Toxicity unit,TU)法、相加指数(Additive index,AI)法和混合毒性指数(Mixtures toxicity index,MTI)法对混合样本进行了定性评价,结果表明:克百威与Cu和Cd两种重金属二元和三元复合作用后主要表现为部分相加和协同作用,说明二元和三元复合毒性较单一毒性增强,且不同混合比例下,联合毒性效应具有差异。TU法与MTI法的评价结果一致,而AI法的结果略有差异。

Joint toxic effects of carbofuran, Cd and Cu to Vibrio fischeri

Toxicity tests were conducted to evaluate the 15 min and 30 min acute toxicity effects of single and mixed samples of carbofuran, cadmium (Cd) and copper (Cu) (carbofuran-Cd and carbofuran-Cu toxicity mixed ratios of 1:1, 1:2 and 2:1, carbofuran-Cd-Cu toxicity mixed ratios of 1:1:1, 1:1:2, 1:2:1 and 2:1:1) to Vibrio fischeri, and to calculate the median effective concentration (EC₅₀) of the single and mixed samples. EC₅₀ values of carbofuran, Cd and Cu for 15 min tests are 101.29, 13.11 and 47.06 mg·L^-1, and that for 30 min tests are 107.88, 11.17 and 39.73 mg·L^-1 respectively. Toxicity unit (TU) method, mixtures toxicity index (MTI) method and additive index (AI) method were used to evaluate the joint toxicity of carbofuran, Cd and Cu to Vibrio fischeri. The results show that the joint toxicity of carbofuran-Cd, carbofuran-Cu and carbofuran-Cd-Cu are partial additive and synergistic effects, which present that the joint toxicity are higher than the single toxicity. The joint toxicity of binary and ternary mixtures to Vibrio fischeri depend on the different mixed ratios. Even though the type are the same, the strength may be different. The evaluation results of TU and MTI method are consistent, while AI method shows slight different from the other two methods.