Earth and Enivornmental Sciences, CUNY Graduate Center, New York, NY, USA.
Environmental Sciences Initiative, CUNY Advanced Science Research Center at the Graduate Center, New York, NY, USA.
Int J Phytoremediation. 2020;22(9):916-930. doi: 10.1080/15226514.2020.1774501. Epub 2020 Jul 17.
This review article focuses on lead (Pb), one of the most ubiquitous and harmful toxicants found in soil. Our objective is to address misconceptions regarding the ability of plants to uptake Pb through their roots and translocate it to above-ground tissues, and their ability to act as hyperaccumulators and thereby phytoextract Pb. In accordance with a number of cited definitions, we suggest that species capable of Pb phytoextraction can be rated with the following three criteria: (1) root uptake above a nominal threshold of 1,000 mg Pb/kg, (2) bioconcentration factor (BCF or shoot/soil concentration) >1, and (3) translocation factor (TF or shoot/root concentration) > 1. We review the literature in the updated USDA Phytoremediation Database and conclude that without amendments: no plant has met all three criteria; no plant has been confirmed as a Pb hyperaccumulator. Our analysis suggests that Pb phytoextraction is not a viable remediation option. Pb phytostabilization, however, may be an effective remediation tool in a variety of settings. Planting some of the many species capable of tolerating soil Pb exposure and sequestering it in or around the root zone will limit Pb movement into other ecosystems, prevent resuspended dusts, and mitigate Pb exposure.
这篇综述文章重点介绍了土壤中最普遍存在和危害最大的有毒物质之一——铅（Pb）。我们的目的是纠正人们对于植物通过根部吸收 Pb 并将其转运到地上组织的能力，以及它们作为超积累植物从而将 Pb 植物提取的能力的误解。根据一些引用的定义，我们建议能够进行 Pb 植物提取的物种可以用以下三个标准进行评估：（1）根部吸收超过名义阈值 1000 mg Pb/kg，（2）生物浓缩系数（BCF 或茎叶/土壤浓度）>1，以及（3）转运系数（TF 或茎叶/根浓度）>1。我们在更新的美国农业部植物修复数据库中审查了文献，并得出结论，没有一种植物符合所有三个标准；没有一种植物被确认为 Pb 超积累植物。我们的分析表明，Pb 植物提取不是一种可行的修复选择。然而，Pb 植物稳定化可能是各种环境下一种有效的修复工具。种植许多能够耐受土壤 Pb 暴露并将其隔离在根区或周围的物种，将限制 Pb 向其他生态系统的迁移，防止再悬浮灰尘，并减轻 Pb 暴露。
