Ettler Vojtěch, Raus Karel, Mihaljevič Martin, Kříbek Bohdan, Vaněk Aleš, Penížek Vít, Sracek Ondra, Koubová Magdalena, Mapani Ben
Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Albertov 6, 128 00, Prague 2, Czech Republic.
Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Albertov 6, 128 00, Prague 2, Czech Republic.
Chemosphere. 2023 Dec;345:140498. doi: 10.1016/j.chemosphere.2023.140498. Epub 2023 Oct 20.
Mining and processing of ores in arid (desert) areas generates high amounts of dust, which might be enriched in potentially harmful elements. We studied dust fractions of ores, soils, and technological materials from mining and related hydrometallurgical operation at former Skorpion Zinc non-sulfide Zn deposit in southern Namibia (closed and placed under maintenance in 2020). Chemical and mineralogical investigation was combined with oral bioaccessibility testing of fine dust fractions (<48 μm and <10 μm) in simulated gastric fluid (SGF) to assess potential risk of intake of metallic contaminants (Cd, Cu, Pb, Zn) for staff operating in the area. The bulk metals concentrations were largely variable and ranked as follows: soils < tailings ≪ Skorpion ores < imported ores and dross used for feed ore blending. Maximum contaminant concentrations in the original granular materials were 927 mg Cd/kg, 9150 mg Cu/kg, 50 g Pb/kg and 706 g Zn/kg, respectively, and generally increased as a function of decreasing grain size. The highest bioaccessible concentrations of Cd and Pb yielded imported ores from Taiwan and Turkey and, together with the milled dross, these samples also exhibited the highest Zn bioaccessibilities. The exposure estimates calculated for a worker (weighing 70 kg) in this mining/ore processing operation at a dust ingestion rate of 100 mg/day indicated that most dust samples (soils, tailings, Skorpion ores) exhibited metals intake values far below tolerable daily intake limits. The overall health risk was limited in all mining and ore processing areas except for the ore blending area, where imported ores and recycled dross enriched in bioaccessible Cd, Pb and/or Zn were used for the ore blending. Safety measures required by the mine operator (wearing of masks by the operating staff) helped to prevent the staff's exposure to potentially contaminated dust even in this blending ore area.
在干旱（沙漠）地区进行矿石开采和加工会产生大量粉尘，这些粉尘中可能富含潜在有害元素。我们研究了纳米比亚南部原斯科尔皮昂锌非硫化锌矿（已于2020年关闭并进入维护状态）采矿及相关湿法冶金作业产生的矿石、土壤和工艺材料中的粉尘组分。化学和矿物学研究与模拟胃液（SGF）中细粉尘组分（<48μm和<10μm）的口腔生物可及性测试相结合，以评估该地区作业人员摄入金属污染物（镉、铜、铅、锌）的潜在风险。大量金属浓度变化很大，排序如下：土壤<尾矿≪斯科尔皮昂矿石<用于配矿的进口矿石和矿渣。原始颗粒材料中的最大污染物浓度分别为927mg镉/千克、9150mg铜/千克、50g铅/千克和706g锌/千克，一般随粒度减小而增加。镉和铅的最高生物可及浓度来自台湾和土耳其的进口矿石，这些样品以及研磨后的矿渣也表现出最高的锌生物可及性。对于该采矿/矿石加工作业中一名体重70千克的工人，按每日100mg的粉尘摄入量计算的暴露估计值表明，大多数粉尘样品（土壤、尾矿、斯科尔皮昂矿石）的金属摄入量远低于每日可耐受摄入量限值。除了配矿区外，所有采矿和矿石加工区域的总体健康风险都有限，在配矿区使用了富含生物可及镉、铅和/或锌的进口矿石和回收矿渣。即使在这个配矿区，矿场经营者要求的安全措施（操作人员佩戴口罩）也有助于防止员工接触潜在污染的粉尘。
