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Bioaccessibility of potentially toxic elements in mine residue particles
Citation:
Jesus Eulisis, C., M. Gonzalez-Chavez, R. Carrillo-Gonzalez, J. Garcia-Cue, D. Fernandez-Reynoso, M. Noerpel, AND K. Scheckel. Bioaccessibility of potentially toxic elements in mine residue particles. Environmental Science: Processes & Impacts. RSC Publishing, Cambridge, Uk, 23(2):367-380, (2021). https://doi.org/10.1039/D0EM00447B
Impact/Purpose:
After a soil field survey in a mining area and experimentation with a wind tunnel, highly erodible particles, by wind, were identified. The pseudo-total, pulmonary, and gastric bioaccessible concentrations of As, Pb, Cd, and Zn were measured. We also identified the chemical species in the small fractions of mine residues by XANES. The atmospheric dispersion of mine residue particles may have direct implications for human health in the neighborhood due to the reactivity of the chemical species contained in the particles.
Description:
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 mm) 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 ¼ 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 mm particles (104 mg m?2 s?1); in contrast, particles <44 mm 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 mm particles and As in the 50–74 mm (40 236 mg kg?1) particles. The highest concentration of inhaled bioaccessible As (343 mg kg?1) was observed in the <20 mm 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.
URLs/Downloads:
DOI: Bioaccessibility of potentially toxic elements in mine residue particles
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