Chlorothalonil is an active biocide applied in antifouling paints, and also used as fungicide in agricultural activities with the purpose to protect plants from foliar and seed diseases. Thus, the aim of this study was to evaluate the effects of chlorothalonil exposure on biochemical biomarkers of oxidative metabolism as well as on cholinesterases in the estuarine polychaete Laeonereis acuta. Animals were exposed for 24 and 96 h to the following nominal concentrations of chlorothalonil: 0.1, 10.0 and 100.0 μg/L. The antioxidant capacity against peroxyl radicals (ACAP) and the activity of the enzymes catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), glutamate cysteine ligase (GCL), acetylcholinesterase (AChE) and propionylcholinesterase (PChE) were evaluated in whole-body tissue. In addition, the levels of reduced glutathione (GSH), lipid peroxidation (LPO), glycogen and lactate levels were also analyzed. A reduction in ACAP levels was observed in animals exposed to the higher chlorothalonil concentration, concomitantly with an induction of GST activity as well as diminution in GSH content in these animals. This disturbance in the redox state of animal tissues leads to an oxidative stress situation, resulting in an induction in LPO levels. It was also demonstrated that chlorothalonil exposure causes alteration in AChE activity, possibly related to damage to membrane lipids. These results demonstrated that chlorothalonil possesses harmful effects to estuarine animals and its use as antifouling biocide has to be carefully reconsidered in risk analysis studies.

氯噻酮是一种活性杀生物剂，用于防污涂料中，还用作农业活动中的杀菌剂，目的是保护植物免受叶面和种子疾病的侵害。因此，本研究的目的是评估百菌清暴露对河口多毛La类古猿Laeonereis acuta氧化代谢的生化生物标志物以及胆碱酯酶的影响。。使动物暴露于以下百菌清的标准浓度：0.1、10.0和100.0μg/ L。抗过氧自由基（ACAP）的抗氧化能力以及过氧化氢酶（CAT），超氧化物歧化酶（SOD），谷胱甘肽S-转移酶（GST），谷氨酸半胱氨酸连接酶（GCL），乙酰胆碱酯酶（AChE）和丙酰胆碱酯酶（PChE）的活性在全身组织中进行了评估。此外，还分析了还原型谷胱甘肽（GSH），脂质过氧化（LPO），糖原和乳酸的水平。在暴露于百菌清浓度较高的动物中，观察到ACAP水平降低，并伴随这些动物GST活性的诱导以及GSH含量的减少。动物组织氧化还原状态的这种紊乱会导致氧化应激情况，导致LPO水平升高。还证明百菌清的暴露会引起AChE活性的改变，可能与膜脂质的损害有关。这些结果表明百菌清对河口动物具有有害作用，在风险分析研究中必须仔细考虑将百菌清用作防污杀生物剂。