School of Veterinary Medicine, Department of Anatomy, Physiology, and Cell Biology, Aquatic Health Program Laboratory, University of California, Davis, California, USA.
Environ Toxicol Chem. 2020 Jul;39(7):1375-1381. doi: 10.1002/etc.4725. Epub 2020 Jun 3.
Herbicides have recently been designated as one of the most frequently detected chemical types in aquatic systems. We evaluated the effect of the herbicide formulations Clearcast® (active ingredient imazamox) and Galleon® SC (active ingredient penoxsulam), in conjunction with the adjuvant Agri-dex®, on the diatom Thalassiosira pseudonana and the copepod Eurytemora affinis and whether their application in invasive aquatic weed control has acutely negative effects on important delta food web species. Herbicide-adjuvant mixtures were more toxic than herbicide formulations alone. For the diatom, 50% inhibition concentration (IC50) were 84.4 mg/L for Clearcast, >100 mg/L for Galleon SC, and 38.5 mg/L for Agri-dex. In the herbicide mixture diatom tests, IC50s decreased to 2.8 mg/L for Clearcast + 64 mg/L Agri-dex and to 6.6 mg/L for Galleon SC + 41 mg/L Agri-dex. In the copepod tests, 50% effect concentrations (EC50s) were 45.4 mg/L for Agri-dex, 31.2 mg/L for Galleon SC, and >100 mg/L for Clearcast. When tested together, EC50s were reduced to 24.1 for Galleon SC and 67.6 mg/L for Clearcast in the presence of 50 mg/L Agri-dex. Environmentally relevant herbicide-adjuvant mixture ratios were at the no-observed-effect level. Mixture interactions between herbicides and adjuvants indicate the potential for increased toxicity in herbicide formulations and tank mixes, especially in consideration of the unlisted, proprietary ingredients which are included in herbicide formulations, making predicting nontarget effects challenging. Environ Toxicol Chem 2020;39:1375-1381. © 2020 SETAC.
最近，除草剂被指定为水生系统中检测到的最常见化学类型之一。我们评估了除草剂配方 Clearcast®（有效成分咪草烟）和 Galleon® SC（有效成分吡氟酰草胺）与助剂 Agri-dex®联合使用对硅藻塔玛多利假海链藻和桡足类动物 Euryte mora affinis 的影响，以及它们在入侵性水生杂草控制中的应用是否对重要的三角洲食物网物种产生急性负面影响。除草剂-助剂混合物比单独的除草剂配方更具毒性。对于硅藻，Clearcast 的 50%抑制浓度 (IC50) 为 84.4mg/L，Galleon SC 的 IC50 大于 100mg/L，Agri-dex 的 IC50 为 38.5mg/L。在除草剂混合物硅藻测试中，IC50 降低至 Clearcast+64mg/L Agri-dex 的 2.8mg/L 和 Galleon SC+41mg/L Agri-dex 的 6.6mg/L。在桡足类动物测试中，Agri-dex 的 50%有效浓度 (EC50) 为 45.4mg/L，Galleon SC 的 EC50 为 31.2mg/L，Clearcast 的 EC50 大于 100mg/L。当一起测试时，在 50mg/L Agri-dex 的存在下，Galleon SC 的 EC50 降低至 24.1，Clearcast 的 EC50 降低至 67.6mg/L。环境相关的除草剂-助剂混合物比例处于无观察效应水平。除草剂和助剂之间的混合物相互作用表明，在除草剂配方和罐混物中可能会增加毒性，特别是考虑到未列入清单的专有成分，这些成分包含在除草剂配方中，这使得预测非目标效应具有挑战性。Environ Toxicol Chem 2020;39:1375-1381. © 2020 SETAC.
