ATC Building, Global Centre for Environmental Remediation, Faculty of Science, University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan, NSW 2308, Australia.
School of Space and Environment, Beihang University, Beijing, China.
J Hazard Mater. 2020 Apr 15;388:121744. doi: 10.1016/j.jhazmat.2019.121744. Epub 2019 Nov 22.
In this study, the predominant Pb minerals prior to and after Pb relative bioavailability (Pb-RBA) and Pb bioaccessibility (Pb-BAc) tests were identified using SEM (scanning electron microscopy), XANES (X-ray absorption near edge structure) and XRD (X-ray diffraction). The correlations between in vitro Pb-BAc (using the UBM (Unified BARGE Method) and RBALP (Relative BioAccessibility Leaching Procedure) models) and in vivo Pb-RBA (using endpoints of kidney and liver in an mice model) were determined. The results demonstrated that both RBALP and UBM (gastric phase) reliably indicate Pb-RBA (Pb-RBA). However, raising the solid:liquid ratio of the gastric phase of UBM is necessary to determine Pb-BAc if the soils contain total Pb >10,000 mg/kg. The comparison of Pb minerals prior to and after in vitro extractions demonstrated that the relatively soluble forms of Pb (PbSO, PbO and MgO Pb) start to dissolve than other forms of Pb minerals, suggesting there was no difference in Pb release between chemical-based (RBALP) and physiologically-based (UBM) models. The identification of the Pb minerals of Pb(PO)Cl and organically-complexed Pb in mice excreta demonstrated that a portion of Pb combined with food and humic acid to generate organically-complexed Pb in mice excreta, and that Pb(PO)Cl is not bioavailable.
在这项研究中，使用 SEM（扫描电子显微镜）、XANES（X 射线吸收近边结构）和 XRD（X 射线衍射）确定了 Pb 相对生物可给性（Pb-RBA）和 Pb 生物可利用性（Pb-BAc）测试前后的主要 Pb 矿物。确定了体外 Pb-BAc（使用 UBM（统一 BARGE 方法）和 RBALP（相对生物可利用性浸出程序）模型）和体内 Pb-RBA（使用小鼠模型中的肾脏和肝脏终点）之间的相关性。结果表明，RBALP 和 UBM（胃相）都能可靠地指示 Pb-RBA（Pb-RBA）。然而，如果土壤中总 Pb 含量>10000mg/kg，则需要提高 UBM 胃相的固液比，以确定 Pb-BAc。体外提取前后 Pb 矿物的比较表明，相对可溶性的 Pb 形式（PbSO、PbO 和 MgOPb）开始溶解，而其他形式的 Pb 矿物则开始溶解，这表明化学基（RBALP）和生理基（UBM）模型之间的 Pb 释放没有差异。在小鼠排泄物中鉴定 Pb（PO）Cl 和有机络合 Pb 的 Pb 矿物表明，一部分 Pb 与食物和腐殖酸结合，在小鼠排泄物中生成有机络合 Pb，而 Pb（PO）Cl 是不可生物利用的。
