title: Assessment of arsenic speciation and bioaccessibility in mine-impacted materials.
abstract: Mine-impacted materials were collected from Victoria, Australia and categorized into three source materials; tailings (n=35), calcinated (n=10) and grey slimes (n=5). Arsenic (As) concentrations in these materials varied over several orders of magnitude (30-47,000mgkg(-1)), with median concentrations of 500, 10,800 and 1500mgkg(-1), respectively. When As bioaccessibility was assessed using the Solubility Bioaccessibility Research Consortium (SBRC) assay, As bioaccessibility ranged between 4 and 90%, with mean gastric phase values of 30%, 49% and 82% for tailings, calcinated and grey slimes, respectively. An analysis of variance (ANOVA) determined that As bioaccessibility was significantly different (P<0.05) between source materials. This was due to differences in As mineralogy, soil particle size as well as the concentration and nature of Fe present. X-ray Absorption Near Edge Structure (XANES) analysis identified arseniosiderite, yukonite, realgar, loellingite and mineral sorbed arsenate species in mine-impacted materials. Despite differences in physicochemical properties, 'mine wastes' are often reported under a generic descriptor. Outcomes from this research highlight that variability in As bioaccessibility can be prescribed to As mineralogy and matrix physicochemical properties, while categorizing samples into sub-groups can provide some notional indication of potential exposure.
authors.affiliation: Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia. Electronic address: cameron.ollson@mymail.unisa.edu.au.
authors.forename: Cameron J
authors.initials: CJ
authors.lastname: Ollson
authors.affiliation: Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia.
authors.forename: Euan
authors.initials: E
authors.lastname: Smith
authors.affiliation: United States Environmental Protection Agency, National Risk Management Research Laboratory, Land Remediation and Pollution Control Division, Cincinnati, OH 45224-1701 USA.
authors.forename: Kirk G
authors.initials: KG
authors.lastname: Scheckel
authors.affiliation: United States Environmental Protection Agency, National Risk Management Research Laboratory, Land Remediation and Pollution Control Division, Cincinnati, OH 45224-1701 USA.
authors.forename: Aaron R
authors.initials: AR
authors.lastname: Betts
authors.affiliation: Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia.
authors.forename: Albert L
authors.initials: AL
authors.lastname: Juhasz
mesh_terms: D001151:Arsenic / Q000032:analysis*; D001315:Australia; D001682:Biological Availability; D008906:Mining; D010316:Particle Size; D012987:Soil; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D001151:Arsenic
keywords: Arsenic; Bioaccessibility; Calcinate; Slime; Tailings