Department of Environmental Sciences, University of California, Riverside, CA 92521, USA.
Department of Environmental Sciences, University of California, Riverside, CA 92521, USA.
Sci Total Environ. 2022 Mar 25;814:152527. doi: 10.1016/j.scitotenv.2021.152527. Epub 2021 Dec 22.
Recycled water (RW) has been increasingly recognized as a valuable source of water for alleviating the global water crisis. When RW is used for agricultural irrigation, many contaminants of emerging concern (CECs) are introduced into the agroecosystem. The ubiquity of CECs in field soil, combined with the toxic, carcinogenic, or endocrine-disrupting nature of some CECs, raises significant concerns over their potential risks to the environment and human health. Understanding such risks and delineating the fate processes of CECs in the water-soil-plant continuum contributes to the safe reuse of RW in agriculture. This review summarizes recent findings and provides an overview of CECs in the water-soil-plant continuum, including their occurrence in RW and irrigated soil, fate processes in agricultural soil, offsite transport including runoff and leaching, and plant uptake, metabolism, and accumulation. The potential ecological and human health risks of CECs are also discussed. Studies to date have shown limited accumulation of CECs in irrigated soils and plants, which may be attributed to multiple attenuation processes in the rhizosphere and plant, suggesting minimal health risks from RW-fed food crops. However, our collective understanding of CECs is rather limited and knowledge of their offsite movement and plant accumulation is particularly scarce for field conditions. Given a large number of CECs and their occurrence at trace levels, it is urgent to develop strategies to prioritize CECs so that future research efforts are focused on CECs with elevated risks for offsite contamination or plant accumulation. Irrigating specific crops such as feed crops and fruit trees may be a viable option to further minimize potential plant accumulation under field conditions. To promote the beneficial reuse of RW in agriculture, it is essential to understand the human health and ecological risks imposed by CEC mixtures and metabolites.
再生水（RW）已被越来越多地视为缓解全球水资源危机的宝贵水源。当 RW 用于农业灌溉时，许多新兴关注污染物（CECs）会被引入农业生态系统。CECs 在田间土壤中普遍存在，再加上一些 CECs 的毒性、致癌性或内分泌干扰特性，引起了人们对其对环境和人类健康的潜在风险的极大关注。了解这些风险并描绘 CECs 在水-土-植物连续体中的归宿过程有助于 RW 在农业中的安全再利用。本综述总结了最近的发现，并概述了水-土-植物连续体中的 CECs，包括它们在 RW 和灌溉土壤中的存在、在农业土壤中的归宿过程、包括径流和淋溶在内的场外迁移，以及植物吸收、代谢和积累。还讨论了 CECs 的潜在生态和人类健康风险。迄今为止的研究表明，CECs 在灌溉土壤和植物中的积累有限，这可能归因于根际和植物中的多种衰减过程，表明 RW 喂养的粮食作物的健康风险最小。然而，我们对 CECs 的集体认识相当有限，并且对它们的场外迁移和植物积累的了解在田间条件下尤其缺乏。鉴于 CECs 的数量众多且痕量存在，因此迫切需要制定优先考虑 CECs 的策略，以便未来的研究工作集中在具有场外污染或植物积累风险升高的 CECs 上。在田间条件下，灌溉特定作物，如饲料作物和果树，可能是进一步最小化潜在植物积累的可行选择。为了促进 RW 在农业中的有益再利用，必须了解 CEC 混合物和代谢物对人类健康和生态风险的影响。
