title: Dust from Zambian smelters: mineralogy and contaminant bioaccessibility.
abstract: Metal smelting is often responsible for local contamination of environmental compartments. Dust materials escaping from the smelting facilities not only settle in the soil, but can also have direct effects on populations living close to these operations (by ingestion or inhalation). In this particular study, we investigate dusts from Cu-Co metal smelters in the Zambian Copperbelt, using a combination of mineralogical techniques (XRD, SEM/EDS, and TEM/EDS), in order to understand the solid speciation of the contaminants, as well as their bioaccessibility using in vitro tests in simulated gastric and lung fluids to assess the exposure risk for humans. The leaching of metals was mainly dependent on the contaminant mineralogy. Based on our results, a potential risk can be recognized, particularly from ingestion of the dust, with bioaccessible fractions ranging from 21 to 89% of the total contaminant concentrations. In contrast, relatively low bioaccessible fractions were observed for simulated lung fluid extracts, with values ranging from 0.01% (Pb) up to 16.5% (Co) of total contaminant concentrations. Daily intakes via oral exposure, calculated for an adult (70 kg, ingestion rate 50 mg dust per day), slightly exceeded the tolerable daily intake limits for Co (1.66× for fly ash and 1.19× for slag dust) and occasionally also for Pb (1.49×, fly ash) and As (1.64×, electrostatic precipitator dust). Cobalt has been suggested as the most important pollutant, and the direct pathways of the population's exposures to dust particles in the industrial parts of the Zambian Copperbelt should be further studied in interdisciplinary investigations.
authors.affiliation: Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University in Prague, Albertov 6, 128 43, Prague 2, Czech Republic, ettler@natur.cuni.cz.
authors.forename: Vojtěch
authors.initials: V
authors.lastname: Ettler
authors.forename: Martina
authors.initials: M
authors.lastname: Vítková
authors.forename: Martin
authors.initials: M
authors.lastname: Mihaljevič
authors.forename: Ondřej
authors.initials: O
authors.lastname: Šebek
authors.forename: Mariana
authors.initials: M
authors.lastname: Klementová
authors.forename: František
authors.initials: F
authors.lastname: Veselovský
authors.forename: Pavel
authors.initials: P
authors.lastname: Vybíral
authors.forename: Bohdan
authors.initials: B
authors.lastname: Kříbek
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000032:analysis*; D001151:Arsenic / Q000032:analysis; D004391:Dust / Q000032:analysis*; D004784:Environmental Monitoring; D006801:Humans; D066298:In Vitro Techniques; D007221:Industry; D008669:Metallurgy; D019216:Metals, Heavy / Q000032:analysis*; D008954:Models, Biological; D010316:Particle Size; D018570:Risk Assessment; D015024:Zambia
chemical_list: D000393:Air Pollutants; D004391:Dust; D019216:Metals, Heavy; D001151:Arsenic
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