Programa de Edafología, Colegio de Postgraduados, Carretera, México-Texcoco 36.5 km, Texcoco, 56230, Mexico.
Programa de Estadística, Colegio de Postgraduados, Carretera, México-Texcoco 36.5 km, Texcoco, 56230, Mexico.
Environ Sci Process Impacts. 2021 Mar 4;23(2):367-380. doi: 10.1039/d0em00447b.
Mining companies used to abandon tailing heaps in countryside regions of Mexico and other countries. Mine residues (MRs) contain a high concentration of potentially toxic elements (PTE). The wind can disperse dust particles (<100 μm) and once suspended in the atmosphere, can be ingested or inhaled; this is a common situation in arid climates. Nowadays, there is little information on the risk of exposure to PTEs from particulate matter dispersed by wind. The pseudo-total PTE in bulk and fractionated MR after aqua regia digestion, the inhalable bioaccessibility with Gamble solution (pH = 7.4), and the gastric bioaccessibility with 0.4 M glycine solution at pH 1.5 were determined. As and Pb chemical species were identified by X-ray absorption near-edge structure (XANES) spectroscopy. The highest rate of dispersion was observed with 74-100 μm particles (104 mg m-2 s-1); in contrast, particles <44 μm had the lowest rate (26 mg m-2 s-1). The highest pseudo-total As (35 961 mg kg-1), Pb (3326 mg kg-1), Cd (44 mg kg-1) and Zn (up to 4678 mg kg-1) concentration was in the <20 μm particles and As in the 50-74 μm (40 236 mg kg-1) particles. The highest concentration of inhaled bioaccessible As (343 mg kg-1) was observed in the <20 μm fraction and the gastric bioaccessible As was 744 mg kg-1, Pb was 1396 mg kg-1, Cd was 19.2 mg kg-1, and Zn was 2048 mg kg-1. The predominant chemical As species was arsenopyrite (92%), while 54% of Pb was in the adsorbed form. Erodible particle matter is a potential risk for humans in case of inhalation or ingestion.
矿业公司过去常常在墨西哥和其他国家的农村地区废弃尾矿堆。矿山尾矿（MRs）中含有高浓度的潜在有毒元素（PTE）。风可以吹散尘埃颗粒（<100μm），一旦悬浮在大气中，就可以被摄入或吸入；这种情况在干旱气候中很常见。如今，关于风散布的颗粒物中 PTE 暴露风险的信息很少。采用王水消解后，测定了大块和分级 MR 中的伪总量 PTE、 Gamble 溶液（pH=7.4）下的可吸入生物利用度和 0.4 M 甘氨酸溶液在 pH 1.5 下的胃生物利用度。利用 X 射线吸收近边结构（XANES）光谱法确定了 As 和 Pb 化学形态。74-100μm 颗粒的分散率最高（104mg m-2 s-1）；相比之下，<44μm 颗粒的分散率最低（26mg m-2 s-1）。<20μm 颗粒中伪总量 As（35961mg kg-1）、Pb（3326mg kg-1）、Cd（44mg kg-1）和 Zn（高达 4678mg kg-1）浓度最高，50-74μm 颗粒中 As 浓度最高（40236mg kg-1）。<20μm 级中可吸入生物利用态 As 浓度最高（343mg kg-1），胃可利用态 As 为 744mg kg-1、Pb 为 1396mg kg-1、Cd 为 19.2mg kg-1、Zn 为 2048mg kg-1。主要的 As 化学形态是毒砂（92%），而 54%的 Pb 以吸附态存在。可侵蚀性颗粒物对人类来说，无论是吸入还是摄入，都是一种潜在的风险。
