Estación Regional del Noroeste, Instituto de Geología, Universidad Nacional Autónoma de México, Colosio y Madrid s/n, 83000, Hermosillo, Sonora, México.
Laboratorio Nacional de Geoquímica y Mineralogía-LANGEM, 04510, Ciudad de México, México.
Environ Geochem Health. 2024 Aug 24;46(10):395. doi: 10.1007/s10653-024-02180-3.
Dispersion of potentially toxic elements associated with efflorescent crusts and mine tailings materials from historical mine sites threaten the environment and human health. Limited research has been done on traceability from historical mining sites in arid and semi-arid regions. Pb isotope systematics was applied to decipher the importance of identifying the mixing of lead sources involved in forming efflorescent salts and the repercussions on traceability. This research assessed mine waste (sulfide-rich and oxide-rich tailings material and efflorescent salts) and street dust from surrounding settlements at a historical mining site in northwestern Mexico, focusing on Pb isotope composition. The isotope data of tailings materials defined a trending line (R = 0.9); the sulfide-rich tailings materials and respective efflorescent salts yielded less radiogenic Pb composition, whereas the oxide-rich tailings and respective efflorescent salts yielded relatively more radiogenic compositions, similar to the geogenic component. The isotope composition of street dust suggests the dispersion of tailings materials into the surroundings. This investigation found that the variability of Pb isotope composition in tailings materials because of the geochemical heterogeneity, ranging from less radiogenic to more radiogenic, can add complexity during environmental assessments because the composition of oxidized materials and efflorescent salts can mask the geogenic component, potentially underestimating the influence on the environmental media.
与历史矿区风化壳和尾矿材料相关的潜在有毒元素的分散对环境和人类健康构成了威胁。在干旱和半干旱地区，对历史矿区的溯源研究还很有限。本研究应用铅同位素系统学来解析在形成风化盐过程中识别相关铅源混合的重要性及其对溯源的影响。本研究评估了墨西哥西北部一个历史矿区的废弃矿（富硫化物和富氧化物尾矿材料及风化盐）和周围定居点的街道灰尘，重点是铅同位素组成。尾矿材料的同位素数据定义了一条趋势线（R=0.9）；富硫化物尾矿材料及其相应的风化盐产生了放射性成因较低的铅组成，而富氧化物尾矿材料及其相应的风化盐则产生了相对更放射性成因的组成，类似于地球成因成分。街道灰尘的同位素组成表明尾矿材料向周围环境的扩散。本研究发现，由于地球化学的非均质性，尾矿材料的铅同位素组成具有很大的可变性，从放射性成因较低到放射性成因较高，这可能会给环境评估带来复杂性，因为氧化材料和风化盐的组成可能会掩盖地球成因成分，从而低估对环境介质的影响。
