Ecossa, Starnberg, Germany.
Eurofins Agroscience Services EAG Laboratories, Ulm, Germany.
Environ Toxicol Chem. 2022 Oct;41(10):2420-2430. doi: 10.1002/etc.5427. Epub 2022 Aug 24.
Fungicides make up the largest part of total pesticide use, with the dithiocarbamate mancozeb being widely applied as a nonsystemic contact pesticide to protect a wide range of field crops against fungal diseases. Although nematodes are key drivers of soil functioning, data on effects of fungicides, and especially mancozeb, on these nontarget organisms are scarce. Therefore, the effects of mancozeb on a soil nematode community from a natural grassland were assessed in small-scale soil microcosms. Nematodes were exposed to mancozeb-spiked soil in six nominal concentrations (7-133 mg/kg dry soil) and analyzed after 14, 56, and 84 days in terms of densities, genus composition, and functional traits. Because this fungicide is known to quickly degrade in soils (50% degradation time <1 day), mancozeb concentrations were analyzed for all sampling occasions. Chemical analysis revealed considerably lower measured concentrations compared with the aimed nominal soil concentrations at the beginning of the exposure (1-18 mg/kg dry soil), suggesting fast degradation during the spiking process. Nevertheless, the native nematode community responded sensitively to the fungicide mancozeb, revealing lower no-observed-effect concentration and 10% effect concentration (EC10) values than reported for other soil invertebrates such as springtails and earthworms. Using the EC10 for the most sensitive nematode community endpoint (percentage of predators and omnivores: 1.2 mg/kg dry soil), the risk assessment exhibited a toxicity exposure ratio of 0.66 and, thus, a high risk of mancozeb for soil nematodes. Keeping in mind their abundance and their central roles in soil food-web functioning, the demonstrated sensitivity to a widely applied fungicide underscores the relevance of the inclusion of nematodes into routine risk-assessment programs for pesticides. Environ Toxicol Chem 2022;41:2420-2430. © 2022 SETAC.
杀真菌剂在总农药使用中占最大部分，代森锰锌作为一种非系统性接触杀虫剂被广泛应用，以保护广泛的大田作物免受真菌病侵害。尽管线虫是土壤功能的关键驱动因素，但关于杀真菌剂，特别是代森锰锌对这些非靶标生物的影响的数据仍然很少。因此，在小型土壤微生境中评估了代森锰锌对天然草原土壤线虫群落的影响。将线虫暴露于代森锰锌污染土壤中，浓度分别为 6 个名义浓度（7-133mg/kg 干土），在 14、56 和 84 天时，根据密度、属组成和功能特征进行分析。由于已知这种杀真菌剂在土壤中迅速降解（50%降解时间<1 天），因此在所有采样点都分析了代森锰锌的浓度。化学分析显示，与暴露开始时的目标名义土壤浓度相比，测量浓度明显较低（1-18mg/kg 干土），表明在添加过程中快速降解。尽管如此，原生线虫群落对杀真菌剂代森锰锌仍表现出高度敏感，其无观察效应浓度（NOEC）和 10%效应浓度（EC10）值均低于跳虫和蚯蚓等其他土壤无脊椎动物的报道。使用最敏感的线虫群落终点（捕食者和杂食者的百分比：1.2mg/kg 干土）的 EC10，风险评估显示毒性暴露比为 0.66，因此代森锰锌对土壤线虫具有高风险。考虑到它们的丰度及其在土壤食物网功能中的核心作用，对线虫对广泛应用的杀真菌剂的敏感性表明，在农药常规风险评估计划中纳入线虫具有重要意义。Environ Toxicol Chem 2022;41:2420-2430。©2022 SETAC。
