title: Nanoparticulate mineral matter from basalt dust wastes.
abstract: Ultra-fine and nano-particles derived from basalt dust wastes (BDW) during "stonemeal" soil fertilizer application have been the subject of some concern recently around the world for their possible adverse effects on human health and environmental pollution. Samples of BDW utilized were obtained from companies in the mining district of Nova Prata in southern Brazil for chemical characterization and nano-mineralogy investigation, using an integrated application of advanced characterization techniques such as X-ray diffraction (XRD), High Resolution-Transmission Electron microscopy (HR-TEM)/(Energy Dispersive Spectroscopy) EDS/(selected-area diffraction pattern) SAED, Field Emission-Scanning Electron Microscopy (FE-SEM)/EDS and granulometric distribution analysis. The investigation has revealed that BDW materials are dominated by SiO2, Al2O3 and Fe2O3, with a complex micromineralogy including alkali feldspar, augite, barite, labradorite, hematite, heulandrite, gypsum, kaolinite, quartz, and smectite. In addition we have identified a number of trace metals such as Cd, Cu, Cr, Zn that are preferentially concentrated into the finer, inhalable, dust fraction and could so present a health hazard in the urban areas around the basalt mining zone. The implication of this observation is that use of these nanometric-sized particulates as soil fertilizer may present different health challenges to those of conventional fertilizers, inviting future work regarding the relative toxicities of these materials. Our investigation on the particle size distribution, nano-particle mineralogy and chemical composition in typical BDW samples highlights the need to develop cleaning procedures to minimise exposure to these natural fertilizing basalt dust wastes and is thus of direct relevance to both the industrial sector of basalt mining and to agriculture in the region.
authors.affiliation: Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil.
authors.forename: Adilson C
authors.initials: AC
authors.lastname: Dalmora
authors.affiliation: Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil.
authors.forename: Claudete G
authors.initials: CG
authors.lastname: Ramos
authors.affiliation: Institute for Environmental Assessment and Water Studies (IDÆA), Spanish National Research Council (CSIC), C/ Jordi Girona 18-26, 08034 Barcelona, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Querol
authors.affiliation: Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil.
authors.forename: Rubens M
authors.initials: RM
authors.lastname: Kautzmann
authors.affiliation: Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil.
authors.forename: Marcos L S
authors.initials: ML
authors.lastname: Oliveira
authors.affiliation: Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil.
authors.forename: Silvio R
authors.initials: SR
authors.lastname: Taffarel
authors.affiliation: Institute for Environmental Assessment and Water Studies (IDÆA), Spanish National Research Council (CSIC), C/ Jordi Girona 18-26, 08034 Barcelona, Spain.
authors.forename: Teresa
authors.initials: T
authors.lastname: Moreno
authors.affiliation: Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS, Brazil. Electronic address: felipeqma@hotmail.com.
authors.forename: Luis F O
authors.initials: LF
authors.lastname: Silva
mesh_terms: D001938:Brazil; D004391:Dust / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods; D005308:Fertilizers; D007220:Industrial Waste; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008903:Minerals / Q000032:analysis*; D008906:Mining; D053758:Nanoparticles / Q000032:analysis* / Q000648:ultrastructure; D010316:Particle Size; D017640:Silicates; D013052:Spectrometry, X-Ray Emission; D014961:X-Ray Diffraction
chemical_list: D004391:Dust; D005308:Fertilizers; D007220:Industrial Waste; D008903:Minerals; D017640:Silicates; C060346:basalt
keywords: Advanced techniques; Brazilian basalt; Nano-mineralogy; Safe environmental; Waste geochemistry