腈苯唑与铜对不同生命阶段斑马鱼的联合急性毒性效应

Combined acute toxic effects of fenbuconazole and copper on zebrafish(Danio rerio)at different life stages

为明确杀菌剂腈苯唑与铜对不同生命阶段斑马鱼的联合急性毒性效应,分别测定了腈苯唑与铜单独暴露,以及二者按照等毒性配比、不同质量浓度配比下的混合体系对斑马鱼不同生命阶段的急性毒性,并分别采用相加指数(AI)法、共毒系数(CTC)法对其联合急性毒性效应进行了评价。结果表明:腈苯唑对斑马鱼成鱼、胚胎、仔鱼的96 h-LC_(50)值分别为2.615、4.121和4.140 mg/L,而铜对该不同阶段斑马鱼的96 h-LC_(50)值分别为0.235、0.353和0.429 mg/L,急性毒性大小均为成鱼>胚胎>仔鱼。两者混配后,对斑马鱼仔鱼与胚胎的毒性效应均呈现出增强的趋势。在等毒性配比中,腈苯唑与铜对仔鱼和胚胎的96 h-LC_(50)值分别为2.051和2.207 mg/L,AI法与CTC法评价结果均为加和作用;对成鱼的96 h-LC_(50)值为1.755 mg/L,但评价结果有差异,分别为拮抗和加和效应。在不同质量浓度配比中,腈苯唑与铜的2:8、5:5、8:2混配组合对胚胎96 h-LC_(50)值分别为0.272、0.378和0.785 mg/L,均表现为协同作用;对仔鱼的96 h-LC_(50)值分别为0.532、0.621和0.934 mg/L,为协同或加和作用,且两种方法评价结果一致;对成鱼的96 h-LC_(50)值分别为0.434、0.653和1.053 mg/L,除了在8:2比例下两种方法的评价结果分别为拮抗和加和效应外,其余比例下均为拮抗效应。由此表明:腈苯唑与铜混配后对于斑马鱼早期生命阶段具有更强的急性毒性,这一发现有助于我们更好地评估腈苯唑与铜混合污染对水生生物的影响。

In order to clarify the combined acute toxic effects of the fungicide fenbuconazole and copper to zebrafish,the acute toxicity of fenbuconazole and copper alone,as well as their combination at equaltoxicity ratio or at different mass concentration ratios to zebrafish during different life stages were determined.The combined acute toxic effects were evaluated using the additional index(AI)method and co-toxicity coefficient(CTC)method.The results showed that the 96 h-LC_(50) values of fenbuconazole for adults,embryos,and larvae of zebrafish were 2.615,4.121 and 4.140 mg/L,respectively,while that of copper were 0.235,0.353,and 0.429 mg/L,respectively.The order of the acute toxicity was adult>embryo>larvae.The toxic effects of the mixtures on both zebrafish larvae and embryos showed an enhancement tendency.At equitoxicity ratio,the 96 h-LC_(50) of the mixed fenbuconazole and copper for larvae and embryos was 2.051 and 2.207 mg/L,respectively,and the evaluation results with AI and CTC methods were both additive;while the 96 h-LC_(50) of the mixture for adults was 1.755 mg/L,and the evaluation results of the two methods were different,which were antagonistic and additive effects,respectively.At different mass concentration ratios,the 96 h-LC_(50) values of fenbuconazole and copper mixed at 2:8,5:5,and 8:2 were 0.272,0.378 and 0.785 mg/L for embryos,respectively,which showed synergistic effects;the 96 h-LC_(50) values were 0.532,0.621 and 0.934 mg/L for larvae,respectively,which showed either synergistic or additive effects.The results of the two methods were consistent for the embryos and larvae.As for the adults zebrafish,the 96 h-LC_(50) values were 0.434、0.653 and 1.053 mg/L,respectively,and the mixtures showed antagonistic effects except that it showed antagonistic and additive effects at 8:2 ratio with the two different methods.The results suggested that the acute toxicity of the mixture of fenbuconazole and copper was stronger to zebrafish at early life stages.This finding will help us to better evaluate the impact of contamination of fenbuconazole and copper on aquatic organisms.