Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824, United States of America.
Department of Environmental Engineering, National Cheng Kung University, Tainan 70701, Taiwan.
Environ Int. 2019 May;126:46-53. doi: 10.1016/j.envint.2019.02.020. Epub 2019 Feb 16.
There has been an on-going pursuit for relations between the levels of chemicals in plants/crops and the source levels in soil or water in order to address impacts of toxic substances on human health and ecological quality. In this research, we applied the quasi-equilibrium partition model to analyze the relations for nonionic organic contaminants between plant/crop roots and external soil/water media. The model relates the in-situ root concentration factors of chemicals from external water into plant/crop roots (RCF) with the system physicochemical parameters and the chemical quasi-equilibrium states with plant/crop roots (α ≤1). With known RCF values, root lipid contents (f), and octanol-water K's, the chemical-plant α values and their ranges of variation at given fK could be calculated. Because of the inherent relation between α and fK, a highly distinct correlation emerges between log RCF and log fK (R = 0.825; n = 368), with the supporting data drawn from 19 disparate soil-plant studies covering some 6 orders of magnitude in fK and 4 orders of magnitude in RCF. This correlation performs far better than any relationship previously developed for predicting the contamination levels of pesticides and toxic organic chemicals in plant/crop roots for assessing risks on food safety.
人们一直在研究植物/作物中化学物质的水平与土壤或水中源水平之间的关系，以解决有毒物质对人类健康和生态质量的影响。在这项研究中，我们应用准平衡分配模型来分析非离子有机污染物在植物/作物根系与外部土壤/水介质之间的关系。该模型将化学物质从外部水中进入植物/作物根系的原位根浓度系数（RCF）与系统物理化学参数以及与植物/作物根系的化学准平衡状态（α≤1）相关联。已知 RCF 值、根脂含量（f）和辛醇-水 K 值，可以计算出给定 fK 下的化学-植物 α 值及其变化范围。由于 α 和 fK 之间存在内在关系，logRCF 和 logfK 之间呈现出高度显著的相关性（R=0.825；n=368），这些数据来自 19 项不同的土壤-植物研究，涵盖了 fK 的 6 个数量级和 RCF 的 4 个数量级。这种相关性比以前为评估食品安全风险而开发的任何预测农药和有毒有机化学物质在植物/作物根系中污染水平的关系都要好得多。
