Environmental contamination from legacy mine waste deposits is a persistent problem due to the long history of hard‐rock mining. Sulfide ore deposits can contain elevated levels of toxic metal(loid)s that, when mobilized by weathering upon O₂ and H₂O infusion, can result in groundwater contamination. Dry climate and lack of vegetative cover result in near‐surface pedogenic processes that produce fine‐particulate secondary minerals that can be translocated as geodusts leading to ingestion or inhalation exposure in nearby communities. In this study, in vitro bioassays were combined with synchrotron‐based X‐ray spectroscopy and diffraction to determine the potential risk for toxic element release from dust (PM₁₀) samples into biofluid simulants. PM₁₀ were isolated from across the oxidative reaction front in the top meter of tailings subjected to 50 years of weathering under semiarid climate and introduced to synthetic gastric and alveolar fluids. Aqueous concentrations were measured as a function of reaction time to determine release kinetics. X‐ray diffraction and absorption spectroscopy analyses were performed to assess associated changes in mineralogy and elemental speciation. In vitro bioaccessibility of arsenic and lead was highest in less‐weathered tailings samples (80–110 cm) and lowest in samples from the suboxic transition zone (40–52 cm). Conversely, zinc release to biofluids was greatest in the highly weathered near‐surface tailings. Results indicate that bioaccessibility of As and Pb was controlled by (i) the solubility of Fe²⁺‐bearing solids, (ii) the prevalence of soluble SO₄²⁻, and (iii) the presence of poorly crystalline Fe(III) oxide sorbents, whereas Zn bioaccessibility was controlled by the pH‐dependent solubility of the stable solid phase.

中文翻译：

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氧化风化作用会降低硫化矿尾矿中PM10排放中有毒金属（金属）的生物可及性。

由于硬岩开采的悠久历史，遗留矿山废物沉积造成的环境污染一直是一个问题。硫化物矿床中可能含有高含量的有毒金属（胶体），当通过注入O ₂和H ₂ O使其风化而动员时，会导致地下水污染。干燥的气候和缺乏植物覆盖导致近地表成岩过程，产生细颗粒的次生矿物质，这些次生矿物质可以作为土尘转移，导致附近社区的摄入或吸入暴露。在这项研究中，将体外生物测定与基于同步加速器的X射线光谱和衍射相结合，以确定从粉尘（PM ₁₀）样品释放到生物流体模拟物中的有毒元素的潜在风险。下午在半干旱气候下经过50年风化的尾矿顶米中，从氧化反应前沿的顶部分离出_10个，并引入合成的胃液和肺泡液中。测量水溶液浓度作为反应时间的函数，以确定释放动力学。进行了X射线衍射和吸收光谱分析，以评估矿物学和元素形态的相关变化。在较少风化的尾矿样品中，砷和铅的体外生物可及性最高（80-110 cm），在亚氧过渡区的样品中最低（40-52 cm）。相反，在高度风化的近地表尾矿中，锌向生物流体的释放最大。结果表明，As和Pb的生物可及性受（i）Fe ²⁺的溶解度控制（ii）可溶性SO ₄ ^2-的流行，以及（iii）结晶性较弱的Fe（III）氧化物吸附剂的存在，而Zn的生物可及性受稳定固相的pH依赖性溶解度控制。