Abstract

Increasing uranium (U) content in soils due to anthropogenic U contamination causes accumulation of U in plants, which greatly increases human health risks. This review identified the diverse sources of soil U contamination and their significant spatial variations in surface soils globally based on 789 soil sampling sites collected from 76 studies. The relationships between U biogeochemical transformation and its bioavailability in soil are significantly affected by soil redox potential, pH, metal (hydr)oxides, organic matter, and microorganisms. The toxicity/detoxification mechanisms of U in plants and microorganisms have been extensively studied, and further studies should combine with omics techniques (proteomics, genomics, and metabolomics) to narrow the knowledge gaps in molecular mechanisms. Moreover, the mechanisms and applicability of phytoremediation and microbial bioremediation in U-contaminated soils were summarized. Based on the present review, we further propose several critical challenges and directions for improving our knowledge and remediation strategies of U contamination in the soil-plant system. This review would help us better understand the geochemical behavior of U in soil-plant systems and its potential risks to human health.

摘要

由于人为 U 污染导致土壤中铀 (U) 含量增加，导致植物中 U 的积累，从而大大增加了人类健康风险。本综述基于从 76 项研究中收集的 789 个土壤采样点，确定了土壤 U 污染的不同来源及其在全球表层土壤中的显着空间变化。U 生物地球化学转化与其在土壤中的生物有效性之间的关系受土壤氧化还原电位、pH、金属（氢）氧化物、有机质和微生物的显着影响。U在植物和微生物中的毒性/解毒机制已被广泛研究，进一步的研究应结合组学技术（蛋白质组学、基因组学和代谢组学）来缩小分子机制方面的知识空白。而且，总结了植物修复和微生物生物修复在U污染土壤中的机理和适用性。基于目前的综述，我们进一步提出了几个关键挑战和方向，以提高我们对土壤-植物系统中 U 污染的认识和修复策略。这篇综述将帮助我们更好地了解 U 在土壤-植物系统中的地球化学行为及其对人类健康的潜在风险。