Unravelling arsenic bioavailability in floodplain soils impacted by mining activities.

Autor: Urango-Cárdenas I; Department of Chemistry, Faculty of Sciences, University of Cordoba, Montería, Colombia., Enamorado-Montes G; Department of Chemistry, Faculty of Sciences, University of Cordoba, Montería, Colombia., Burgos-Nuñez S; Department of Chemistry, Faculty of Sciences, University of Cordoba, Montería, Colombia., Marrugo-Madrid S; Department of Chemistry, Faculty of Sciences, University of Cordoba, Montería, Colombia., Paternina-Uribe R; Department of Chemistry, Faculty of Sciences, University of Cordoba, Montería, Colombia., Marrugo-Negrete J; Department of Chemistry, Faculty of Sciences, University of Cordoba, Montería, Colombia. Electronic address: jmarrugo@correo.unicordoba.edu.co., Díez S; Environmental Chemistry Department, Institute of Environmental Assessment and Water Research, IDAEA-CSIC, E-08034 Barcelona, Spain. Electronic address: sergi.diez@idaea.csic.es.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2024 Oct 15; Vol. 947, pp. 174193. Date of Electronic Publication: 2024 Jun 22.
DOI: 10.1016/j.scitotenv.2024.174193
Abstrakt: Gold mining not only introduces mercury (Hg) contamination to soils but also facilitates the mobilization of other toxic substances, including arsenic (As). This study assessed the total content, chemical species, and bioavailable fraction of As in surface soils impacted by mining residues during frequent flooding. Analysis of 207 soil samples across the floodplain region of La Mojana, Colombia, screened to 2 mm with polyethylene mesh, revealed significant correlations (p < 0.05) between inorganic As, the residual phase, sulphur (S), iron (Fe), manganese (Mn), and aluminum (Al), indicating associations with sulfides and oxyhydroxides of Fe and Mn. The origin of toxicity was linked to suspended materials transported by rivers during flooding in areas with intense mining activity. Sites with better oxidizing conditions exhibited a higher presence of phases associated with amorphous and crystalline oxides in non-flooded areas. Although the bioavailable fraction was minimal in flooded sites, reducing conditions facilitated As mobility, resulting in higher concentrations in deeper soil layers, particularly as As(III). The contamination factor (CF) ranged from 1.3 to 11.1, and the geochemical index (Igeo) ranged from -0.2 to 2.9, indicating a moderate to high As contamination level in soils. This poses potential health risks, considering the agricultural use of these soils.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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