Amending Soils With Phosphate As Means To Mitigate Soil Lead Hazard: A Critical Review Of The State Of The Science
Amending Soils With Phosphate As Means To Mitigate Soil Lead Hazard: A Critical Review Of The State Of The Science
复制标题
DOI：
10.1080/10937404.2013.825216
复制
发表时间：
2013-08
期刊：
影响因子：
--
通讯作者：
K. Scheckel;G. Diamond;Michele Burgess;J. Klotzbach;M. Maddaloni;B. Miller;C. Partridge;S. Serda
中科院分区：
文献类型：
--
作者：
K. Scheckel;G. Diamond;Michele Burgess;J. Klotzbach;M. Maddaloni;B. Miller;C. Partridge;S. Serda
摄入的土壤和表面灰尘可能是暴露于铅污染环境的儿童血铅 (Pb) 水平升高的重要原因。缓解策略通常侧重于挖掘和清除受污染的土壤。然而，这对于解决城市环境中经常遇到的人口稠密地区广泛传播的污染问题并不总是可行。用磷酸盐改良土壤的基本原理是，磷酸盐会促进土壤中高度不溶性铅物种（例如，磷氯铅矿矿物）的形成，这些铅物种在摄入后将保持不溶性，因此无法进入胃肠道（GIT）的吸收机制。用磷酸盐改良土壤可能会与其他减少污染土壤接触或迁移的方法结合使用，例如用草皮等绿色覆盖物覆盖土壤，用覆盖物、凸起的花园床或砾石覆盖干净的土壤。这些修复策略可能比挖掘和清除土壤成本更低，破坏性也小得多。本综述评估了磷酸盐改良剂降低土壤铅生物利用率的功效证据。审查了以下方面的证据：(1) 预计会影响生物有效性的铅和磷酸盐的物理和化学相互作用，(2) 磷酸盐改良剂对土壤铅生物可及性的影响（即，预测的胃肠道中铅的溶解度），以及 (3) 在人类和动物模型中进行的改良土壤的生物有效性生物测定结果。还讨论了实际实施问题，例如评估功效的标准和方法，以及磷酸盐对土壤中共污染物的流动性和生物利用度的潜在影响。
Ingested soil and surface dust may be important contributors to elevated blood lead (Pb) levels in children exposed to Pb contaminated environments. Mitigation strategies have typically focused on excavation and removal of the contaminated soil. However, this is not always feasible for addressing widely disseminated contamination in populated areas often encountered in urban environments. The rationale for amending soils with phosphate is that phosphate will promote formation of highly insoluble Pb species (e.g., pyromorphite minerals) in soil, which will remain insoluble after ingestion and, therefore, inaccessible to absorption mechanisms in the gastrointestinal tract (GIT). Amending soil with phosphate might potentially be used in combination with other methods that reduce contact with or migration of contaminated soils, such as covering the soil with a green cap such as sod, clean soil with mulch, raised garden beds, or gravel. These remediation strategies may be less expensive and far less disruptive than excavation and removal of soil. This review evaluates evidence for efficacy of phosphate amendments for decreasing soil Pb bioavailability. Evidence is reviewed for (1) physical and chemical interactions of Pb and phosphate that would be expected to influence bioavailability, (2) effects of phosphate amendments on soil Pb bioaccessibility (i.e., predicted solubility of Pb in the GIT), and (3) results of bioavailability bioassays of amended soils conducted in humans and animal models. Practical implementation issues, such as criteria and methods for evaluating efficacy, and potential effects of phosphate on mobility and bioavailability of co-contaminants in soil are also discussed.