Key Laboratory of Wet Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.
Key Laboratory of Wet Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Ecotoxicol Environ Saf. 2018 Oct;161:662-668. doi: 10.1016/j.ecoenv.2018.06.041. Epub 2018 Jun 20.
Because the extensive use of Cu-based fungicides, the accumulation of Cu in agricultural soil has been widely reported. However, little information is known about the bioavailability of Cu deriving from different fungicides in soil. This paper investigated both the distribution behaviors of Cu from two commonly used fungicides (Bordeaux mixture and copper oxychloride) during the aging process and the toxicological effects of Cu on earthworms. Copper nitrate was selected as a comparison during the aging process. The distribution process of exogenous Cu into different soil fractions involved an initial rapid retention (the first 8 weeks) and a following slow continuous retention. Moreover, Cu mainly moved from exchangeable and carbonate fractions to Fe-Mn oxides-combined fraction during the aging process. The Elovich model fit well with the available Cu aging process, and the transformation rate was in the order of Cu(NO) > Bordeaux mixture > copper oxychloride. On the other hand, the biological responses of earthworms showed that catalase activities and malondialdehyde contents of the copper oxychloride treated earthworms were significantly higher than those of Bordeaux mixture treated earthworms. Also, body Cu loads of earthworms from different Cu compounds spiked soils were in the following order: copper oxychloride > Bordeaux mixture. Thus, the bioavailability of Cu from copper oxychloride in soil was significantly higher than that of Bordeaux mixture, and different Cu compounds should be taken into consideration when studying the bioavailability of Cu-based fungicides in the soil.
由于铜基杀菌剂的广泛使用，农业土壤中铜的积累已得到广泛报道。然而，关于土壤中不同杀菌剂来源的铜的生物可利用性知之甚少。本文研究了两种常用杀菌剂（波尔多混合物和碱式氯化铜）在老化过程中的铜分布行为以及铜对蚯蚓的毒理效应。在老化过程中，选择硝酸铜作为比较。外源铜进入不同土壤组分的分布过程涉及初始快速保留（前 8 周）和随后的缓慢持续保留。此外，在老化过程中，铜主要从可交换态和碳酸盐态向铁锰氧化物结合态迁移。Elovich 模型很好地拟合了有效铜的老化过程，转化速率的顺序为 Cu(NO₃)₂＞波尔多混合物＞碱式氯化铜。另一方面，蚯蚓的生物响应表明，铜处理的蚯蚓的过氧化氢酶活性和丙二醛含量明显高于波尔多混合物处理的蚯蚓。此外，来自不同含铜化合物添加土壤的蚯蚓的体内铜负荷顺序为：碱式氯化铜＞波尔多混合物。因此，土壤中碱式氯化铜中的铜的生物可利用性明显高于波尔多混合物，在研究土壤中铜基杀菌剂的铜生物可利用性时，应考虑不同的铜化合物。
