Contaminant bioaccessibility in abandoned mine tailings in Namibia changes along a climatic gradient

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60460709%3A41210%2F25%3A101858" target="_blank" >RIV/60460709:41210/25:101858 - isvavai.cz</a>

Výsledek na webu

<a href="https://pubs.rsc.org/en/content/articlehtml/2025/em/d5em00060b" target="_blank" >https://pubs.rsc.org/en/content/articlehtml/2025/em/d5em00060b</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/d5em00060b" target="_blank" >10.1039/d5em00060b</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Contaminant bioaccessibility in abandoned mine tailings in Namibia changes along a climatic gradient

Popis výsledku v původním jazyce

Fine-grained dust from tailing storage facilities in abandoned sulfide-ore mining areas represents an important source of environmental contamination. Fine fractions (<48 µm and <10 µm) of tailings from three old mining sites situated along a climatic gradient from hot semiarid to cold desert conditions in Namibia were studied: Kombat (Cu–Pb–Zn; rainfall ~500 mm), Oamites (Cu; ~120 mm), Namib Lead & Zinc (Pb–Zn; ~0 mm). Multi-method mineralogical and geochemical investigations were adopted to assess the binding and gastric bioaccessibility of the metal(loid)s and to evaluate the associated human health risks. The total concentrations of contaminants in the tailings generally increased with the decreasing particle size (up to 134 mg As kg-1, 14[thin space (1/6-em)]900 mg Cu kg-1, 8880 mg Pb kg-1, 13[thin space (1/6-em)]300 mg Zn kg-1). The mean bioaccessible fractions varied substantially between the sites and were significantly higher for the tailings from the sites with a higher rainfall (73–82% versus 22%). The mineralogical composition of the tailings, reflecting the original mineralogy and the degree of the weathering process, is the main driver controlling the bioaccessibility of the metal(loid)s. In desert environments, metal(loid)s in tailings are bound in sulfides or sequestered in secondary Fe oxyhydroxides and/or Fe hydroxysulfates, all of which are insoluble in simulated gastric fluid. In contrast, tailings from areas with higher precipitation contain metal(loid)s hosted in carbonate phases (malachite, cerussite), which are highly soluble under gastric conditions. Based on the higher contaminant bioaccessibility, the vicinity of the settlement and farmlands, and a higher percentage of wind-erodible fine particles, a higher risk for human health has thus been identified for the Kombat site, where further remediation of the existing tailings storage facility is highly recommended.

Název v anglickém jazyce

Contaminant bioaccessibility in abandoned mine tailings in Namibia changes along a climatic gradient

Popis výsledku anglicky

Fine-grained dust from tailing storage facilities in abandoned sulfide-ore mining areas represents an important source of environmental contamination. Fine fractions (<48 µm and <10 µm) of tailings from three old mining sites situated along a climatic gradient from hot semiarid to cold desert conditions in Namibia were studied: Kombat (Cu–Pb–Zn; rainfall ~500 mm), Oamites (Cu; ~120 mm), Namib Lead & Zinc (Pb–Zn; ~0 mm). Multi-method mineralogical and geochemical investigations were adopted to assess the binding and gastric bioaccessibility of the metal(loid)s and to evaluate the associated human health risks. The total concentrations of contaminants in the tailings generally increased with the decreasing particle size (up to 134 mg As kg-1, 14[thin space (1/6-em)]900 mg Cu kg-1, 8880 mg Pb kg-1, 13[thin space (1/6-em)]300 mg Zn kg-1). The mean bioaccessible fractions varied substantially between the sites and were significantly higher for the tailings from the sites with a higher rainfall (73–82% versus 22%). The mineralogical composition of the tailings, reflecting the original mineralogy and the degree of the weathering process, is the main driver controlling the bioaccessibility of the metal(loid)s. In desert environments, metal(loid)s in tailings are bound in sulfides or sequestered in secondary Fe oxyhydroxides and/or Fe hydroxysulfates, all of which are insoluble in simulated gastric fluid. In contrast, tailings from areas with higher precipitation contain metal(loid)s hosted in carbonate phases (malachite, cerussite), which are highly soluble under gastric conditions. Based on the higher contaminant bioaccessibility, the vicinity of the settlement and farmlands, and a higher percentage of wind-erodible fine particles, a higher risk for human health has thus been identified for the Kombat site, where further remediation of the existing tailings storage facility is highly recommended.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20701 - Environmental and geological engineering, geotechnics

Projekt

<a href="/cs/project/GA23-05051S" target="_blank" >GA23-05051S: Kovy a jejich izotopy v prostředí aktivních a opuštěných důlních oblastí subsaharské Afriky – pochopení jejich geochemie a environmentálních dopadů</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Environmental Science-Processes & Impacts

ISSN

2050-7895

e-ISSN

2050-7895

Svazek periodika

27

Číslo periodika v rámci svazku

4

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

15

Strana od-do

1088-1102

Kód UT WoS článku

001451109000001

EID výsledku v databázi Scopus

2-s2.0-105001188347