title: Size-dependent characterisation of historical gold mine wastes to examine human pathways of exposure to arsenic and other potentially toxic elements.
abstract: Abandoned historical gold mining wastes often exist as geographically extensive, unremediated, and poorly contained deposits that contain elevated levels of As and other potentially toxic elements (PTEs). One of the key variables governing human exposure to PTEs in mine waste is particle size. By applying a size-resolved approach to mine waste characterisation, this study reports on the proportions of mine waste relevant to human exposure and mobility, as well as their corresponding PTE concentrations, in four distinct historical mine wastes from the gold province in Central Victoria, Australia. To the best of our knowledge, such a detailed investigation and comparison of historical mining wastes has not been conducted in this mining-affected region. Mass distribution analysis revealed notable proportions of waste material in the readily ingestible size fraction (≤250 µm; 36.1-75.6 %) and the dust size fraction (≤100 µm; 5.9-45.6 %), suggesting a high potential for human exposure and dust mobilisation. Common to all mine waste types were statistically significant inverse trends between particle size and levels of As and Zn. Enrichment of As in the finest investigated size fraction (≤53 µm) is of particular concern as these particles are highly susceptible to long-distance atmospheric transport. Human populations that reside in the prevailing wind direction from a mine waste deposit may be at risk of As exposure via inhalation and/or ingestion pathways. Enrichment of PTEs in the finer size fractions indicates that human health risk assessments based on bulk contaminant concentrations may underestimate potential exposure intensities.
authors.affiliation: Faculty of Science and Technology, Federation University Australia, Mount Helen, VIC, Australia. r.matin@federation.edu.au.
authors.forename: Rachael
authors.identifier: http://orcid.org/0000-0003-2656-4288
authors.initials: R
authors.lastname: Martin
authors.affiliation: Faculty of Science and Technology, Federation University Australia, Mount Helen, VIC, Australia.
authors.forename: Kim
authors.initials: K
authors.lastname: Dowling
authors.affiliation: Faculty of Science and Technology, Federation University Australia, Mount Helen, VIC, Australia.|Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC, Australia.
authors.forename: Dora C
authors.initials: DC
authors.lastname: Pearce
authors.affiliation: Faculty of Science and Technology, Federation University Australia, Mount Helen, VIC, Australia.
authors.forename: Singarayer
authors.initials: S
authors.lastname: Florentine
authors.affiliation: Neutron Activation Group, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, Australia.
authors.forename: John W
authors.initials: JW
authors.lastname: Bennett
authors.affiliation: Neutron Activation Group, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, Australia.
authors.forename: Attila
authors.initials: A
authors.lastname: Stopic
mesh_terms: D001151:Arsenic / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods; D004785:Environmental Pollutants / Q000032:analysis* / Q000737:chemistry; D006046:Gold; D006801:Humans; D007220:Industrial Waste / Q000032:analysis; D008906:Mining; D010316:Particle Size; D018570:Risk Assessment; D014739:Victoria; D015032:Zinc / Q000032:analysis / Q000737:chemistry
chemical_list: D004785:Environmental Pollutants; D007220:Industrial Waste; D006046:Gold; D015032:Zinc; D001151:Arsenic
keywords: Arsenic; Dust; Human exposure; Mining waste; Particle size; Tailings