A review of the pesticide MCPA in the land‐water environment and emerging research needs
A review of the pesticide MCPA in the land‐water environment and emerging research needs
复制标题
陆地水环境中农药 MCPA 的综述和新的研究需求
作者：
Phoebe A. Morton;C. Fennell;R. Cassidy;D. Doody;O. Fenton;P. Mellander;P. Jordan
由于其高溶解度和对土壤基质的吸附性差，2‐甲基‐4‐氯苯氧乙酸（MCPA）很容易被输送到地表水和地下水中，从而导致水质受损和违反立法标准。然而，对集水区尺度动态和运移的理解仍然很差，特别是在非均质水文地质背景下。虽然已知MCPA在好氧条件下降解，但在厌氧环境中可能发生可忽略不计的分解，可能在饱和土壤中留下遗产。应用后的快速径流路径可能是运输路线，但从厌氧区动员遗留MCPA的相对贡献尚未被量化，这使得在监测程序中遇到的MCPA来源的描述具有挑战性。虽然已经研究了生态毒理学效应，但对于MCPA（及其降解产物）与其他农药、营养物质或胶体的相互作用，以及这些相互作用如何与环境条件结合而导致多重应激源效应，人们知之甚少。我们研究了MCPA知识的状态，使用来自爱尔兰的案例研究示例，并考虑其在水体和饮用水供应中广泛检测的含义。本文确定了在不断发展的农业、社会和政治环境中确保可持续和安全使用MCPA所需的研究主题。其中包括需要确定缓解措施和（或）替代疗法，深入了解影响动员和衰减的条件，绘制迁移路径图，并确定直接、协同和拮抗的生态毒理学效应。
Due to its high solubility and poor adsorption to the soil matrix, the post‐emergence herbicide 2‐methyl‐4‐chlorophenoxyacetic acid (MCPA) is susceptible to transport into surface and groundwater bodies, where it can result in compromised water quality and breaches of legislative standards. However, there is still poor understanding of catchment scale dynamics and transport, particularly across heterogeneous hydrogeological settings. While it is known that MCPA degrades under aerobic conditions, negligible breakdown can occur in anaerobic environments, potentially creating a legacy in saturated soils. Fast runoff pathways post application are likely transport routes, but the relative contribution from the mobilization of legacy MCPA from anaerobic zones has yet to be quantified, making the delineation of MCPA sources encountered during monitoring programs challenging. While ecotoxicological effects have been examined, little is known about the interaction of MCPA (and its degradation products) with other pesticides, with nutrients or with colloids, and how this combines with environmental conditions to contribute to multiple stressor effects. We examine the state of MCPA knowledge, using case study examples from Ireland, and consider the implications of its widespread detection in waterbodies and drinking water supplies. Research themes required to ensure the sustainable and safe use of MCPA in an evolving agricultural, social and political landscape are identified here. These include the need to identify mitigation measures and/or alternative treatments, to gain insights into the conditions governing mobilization and attenuation, to map pathways of migration and to identify direct, synergistic and antagonistic ecotoxicological effects.