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Keywords = asbestiform

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16 pages, 6704 KiB  
Article
Marble Waste Dump Yard in Rajasthan, India Revealed as a Potential Asbestos Exposure Hazard
by Raja Singh, Sean Fitzgerald, Rima Dada and Arthur L. Frank
Int. J. Environ. Res. Public Health 2025, 22(2), 215; https://doi.org/10.3390/ijerph22020215 - 4 Feb 2025
Viewed by 2421
Abstract
Asbestos is a fibrous variety of certain minerals, some of which occur naturally as an accessory to a wide variety of mineral resources. Although asbestos itself has been historically mined for various useful properties, the negative health effects of asbestos dust have greatly [...] Read more.
Asbestos is a fibrous variety of certain minerals, some of which occur naturally as an accessory to a wide variety of mineral resources. Although asbestos itself has been historically mined for various useful properties, the negative health effects of asbestos dust have greatly diminished it as a useful earth material, as many countries have banned the use of these fibrous minerals based on those health concerns. Resulting regulations of asbestos have focused primarily on intentionally mined material used in product manufacturing, such as building materials made with beneficiated asbestos and their derivative exposures, e.g., airborne asbestos in schools with asbestos-containing materials. The hazards of asbestos as unintended byproducts have not been as extensively considered, although this “contamination” has been repeatedly observed in common earth materials including talc, vermiculite, sand, and gravel. This study reveals such contamination of ornamental and dimension stone commonly referred to as “marble”. Asbestos types that can be associated with certain Indian marble reserves include asbestiform tremolite, actinolite, anthophyllite, and chrysotile asbestos. This case reveals such contamination in a marble reserve in Rajsamand, Rajasthan. At this location, marble dust in slurry is disposed at waste collection points, unfortunately including a location now open to the public that has become a tourist destination. Using Transmission Electron Microscopy (TEM) in this study, dust from this location revealed abundant tremolite asbestos fibres in the disaggregated dust. This poses potential health risks to the workers, bystanders, and tourists that may be exposed to this recognized carcinogen, a known cause of mesothelioma, lung cancer, and other asbestos-related diseases. Full article
(This article belongs to the Section Environmental Health)
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10 pages, 3164 KiB  
Article
Assessment of Optical and Scanning Electron Microscopies for the Identification and Quantification of Asbestos Fibers and Typical Asbestos Bodies in Human Colorectal Cancer Tissues
by Alessandro Croce, Marinella Bertolotti, Donata Bellis, Alex Glorioso, Carlotta Bertolina, Marianna Farotto, Fabio Giacchero, Annalisa Roveta and Antonio Maconi
Chemosensors 2024, 12(10), 200; https://doi.org/10.3390/chemosensors12100200 - 1 Oct 2024
Viewed by 1514
Abstract
Asbestos research, identification, and quantification have been performed over the years, and the relationship between fiber inhalation and lung disease development is well defined. The same cannot be said for the gastroenteric system: the International Agency for Research on Cancer (IARC) believes that [...] Read more.
Asbestos research, identification, and quantification have been performed over the years, and the relationship between fiber inhalation and lung disease development is well defined. The same cannot be said for the gastroenteric system: the International Agency for Research on Cancer (IARC) believes that colorectal cancer (CRC) could be associated with asbestos exposure, but research has not demonstrated a casual nexus between exposure and CRC, despite highlighting an association tendency. The combination of scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) is the most applied technique in asbestos fiber identification in tissues and intestinal mucosa. In this study, SEM/EDS was applied to evaluate the presence of asbestos fibers and bodies (ABs) inside the tissue of eleven patients affected by CRC who had undergone environmental exposure due to living in an asbestos-polluted area where an Eternit plant had been active in the past. This technique was coupled with optical microscopy (OM) to verify whether the latter could be applied to evaluate the presence of these mineral phases, with the goal of understanding its suitability for identifying fibers and ABs in colon tissues. In addition to verifying the presence of fibers, this study allowed us to identify the deposition site of said fibers within the sample and possibly detect associated tissue reactions using OM, over a shorter time and at lower costs. Despite being a preliminary and descriptive work, the obtained results allowed us to propose a method involving first-sample OM observation to identify regulated (fibers with a length ≥ 5 μm, a thickness ≤ 3 μm, and a length/thickness ratio > 3) asbestos phases and ABs in the extra-respiratory system. In fact, OM and SEM/EDS provided similar information: no asbestiform morphology or ABs were found, but phyllosilicates and other inorganic materials were identified. This research needs to be continued using higher-resolution techniques to definitively rule out the presence of these fibers inside tissues whilst also increasing the number of patients involved. Full article
(This article belongs to the Section Imaging for (Bio)chemical Sensing)
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18 pages, 3937 KiB  
Article
Localization and Dimensional Range of Amphibole Particles Retrieved from Human Alveolar Epithelial Cells
by Ruggero Vigliaturo, Maja Jamnik, Goran Dražić, Marjetka Podobnik, Magda Tušek Žnidarič, Giancarlo Della Ventura, Günther J. Redhammer, Nada Žnidaršič, Simon Caserman and Reto Gieré
Minerals 2024, 14(1), 101; https://doi.org/10.3390/min14010101 - 16 Jan 2024
Cited by 1 | Viewed by 1750
Abstract
Amphibole asbestos is related to multiple diseases, mainly those targeting the lungs. Asbestos-related malignancies can also be caused by non-regulated asbestiform minerals and some elongated mineral particles (EMPs). In particular, the role of nano- and micro-sized EMPs internalized by lung epithelial cells must [...] Read more.
Amphibole asbestos is related to multiple diseases, mainly those targeting the lungs. Asbestos-related malignancies can also be caused by non-regulated asbestiform minerals and some elongated mineral particles (EMPs). In particular, the role of nano- and micro-sized EMPs internalized by lung epithelial cells must be clarified. This is of major importance when considering that EMPs to which humans are exposed are likely a highly heterogeneous mix of different mineral types, shapes, and sizes. Here, we document that particles smaller than 4.54 µm in length and smaller than 0.89 µm in width (e.g., particles that do not fit the regulatory categories to be identified as asbestos) are easily internalized because of their specific dimensions, surface charge, and shape (mostly dictated by the aspect ratio L/w). Once internalized, these particles can be found in proximity to the cell nucleus, in vesicles, and in the cytoplasm. Examining the localization of particles in cells provides important information, which helps in determining the physicochemical environment found inside the biological compartment, thus allowing for a better comprehension of the mineralogical transformation that might happen after internalization by cells. Full article
(This article belongs to the Section Environmental Mineralogy and Biogeochemistry)
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5 pages, 3161 KiB  
Proceeding Paper
Mineralogical Characterization of PM10 over the Central Himalayan Region
by Sakshi Gupta, Priyanka Srivastava, Manish Naja, Nikki Choudhary and Sudhir Kumar Sharma
Environ. Sci. Proc. 2023, 27(1), 10; https://doi.org/10.3390/ecas2023-15923 - 8 Nov 2023
Viewed by 789
Abstract
The air quality of the Himalayan region of India is deteriorating due to the increasing load of particulate matter that is emitted from various local and regional sources, as well as to the transit of dust-related pollutants from the Indo-Gangetic Plain (IGP) and [...] Read more.
The air quality of the Himalayan region of India is deteriorating due to the increasing load of particulate matter that is emitted from various local and regional sources, as well as to the transit of dust-related pollutants from the Indo-Gangetic Plain (IGP) and surrounding areas. In this study, the mineralogical characteristics of coarse mode particulate matter (PM10) was analyzed using the X-ray diffraction (XRD) technique from January to December 2019 over Nainital (29.39° N, 79.45° E; altitude: 1958 m above mean sea level), a central Himalayan region of India. XRD analysis of PM10 samples showed the presence of clay minerals, crystalline silicate minerals, carbonate minerals, and asbestiform minerals. It was shown that quartz minerals with significant levels of crystallinity were present in all the samples. Other minerals that are contributing to the soil dust were also observed in the analysis (CaFe2O4, CaCO3, CaMg(CO3)2, calcium ammonium silicate hydrate (C-A-S-H), gypsum, kaolinite, illite, augite, and montmorillonite). The minerals ammonium sulphate, hematite, and magnetite were also found in the samples and are suggested to be from biogenic and anthropogenic activities, including biomass burning, fuel combustion, vehicle exhaust, construction activities, etc. This study indicated that the majority of the minerals in PM10 that were present in this Himalayan region are from soil/crustal dust. Full article
(This article belongs to the Proceedings of The 6th International Electronic Conference on Atmospheric Sciences)
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19 pages, 21682 KiB  
Review
A Review of the Mineralogy, Petrography, and Geochemistry of Serpentinite from Calabria Regions (Southern Italy): Problem or Georesource?
by Rosalda Punturo, Roberto Visalli and Rosolino Cirrincione
Minerals 2023, 13(9), 1132; https://doi.org/10.3390/min13091132 - 26 Aug 2023
Cited by 5 | Viewed by 2633
Abstract
Serpentinite rocks testify to the ocean-floor metamorphism that took place and transformed the original mineralogy and fabric of previous ultramafic rocks. Due to their tectonic and petrological importance, in recent decades, there has been increasing interest in serpentinites. From the economic point of [...] Read more.
Serpentinite rocks testify to the ocean-floor metamorphism that took place and transformed the original mineralogy and fabric of previous ultramafic rocks. Due to their tectonic and petrological importance, in recent decades, there has been increasing interest in serpentinites. From the economic point of view, it is worth noting that, due to their beauty and attractiveness, serpentinite rocks have been exploited and traded as building and ornamental stones since prehistorical times worldwide. In this work, we provide a comprehensive report of the petrographic, mineralogical, petrophysical, and geochemical features of the serpentinites cropping out in the northern sector of the Calabria–Peloritani Orogen (Italy), where the historical quarries are located. Since these serpentinite rocks have been traded for a long time and employed as an excellent building material, their detailed knowledge may provide a useful tool to understand their behavior when they are employed as building materials, to predict their performances upon emplacement in monuments, and to plan correct restoration by considering the provenance of the lithotypes employed. Moreover, comprehensive characterization is also particularly important because it has been reported that serpentinites from Calabria may contain asbestiform and other fibrous minerals, as testified by the occurrence of chrysotile, tremolite, and actinolite asbestos located within the veins, which could lead to health problems due to asbestos fiber exposure. Finally, serpentinite may be considered as an important potential CO2 sequestration sink. Full article
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16 pages, 2932 KiB  
Article
Pathogenic Potential of Respirable Spodumene Cleavage Fragments following Application of Regulatory Counting Criteria for Asbestiform Fibres
by Melinda Gardner, Martyn Cross, Sue Reed, Maggie Davidson, Rick Hughes and Jacques Oosthuizen
Int. J. Environ. Res. Public Health 2022, 19(24), 16649; https://doi.org/10.3390/ijerph192416649 - 11 Dec 2022
Viewed by 3049
Abstract
Health risks from exposure to lithium-bearing spodumene cleavage fragments are unknown. While asbestiform fibres can lead to fibrosis, mesothelioma and lung cancer, controversy remains whether non-asbestiform cleavage fragments, having equivalent dimensions, elicit similar pathologic responses. The mineralogy of respirable particles from two alpha [...] Read more.
Health risks from exposure to lithium-bearing spodumene cleavage fragments are unknown. While asbestiform fibres can lead to fibrosis, mesothelioma and lung cancer, controversy remains whether non-asbestiform cleavage fragments, having equivalent dimensions, elicit similar pathologic responses. The mineralogy of respirable particles from two alpha (α)-spodumene concentrate grades (chemical and technical) were characterised using semi-quantitative X-ray diffraction (XRD). Particles were measured using scanning electron microscopy (SEM) and the dimensions (length [L], diameter [D], aspect ratio [AR]) applied to regulatory counting criteria for asbestiform fibres. Application of the current World Health Organization (WHO) and National Occupational Health and Safety Commission (NOHSC) counting criteria, L ˃ 5 µm, D ˂ 3 µm, AR ˃ 3:1, to 10 SEM images of each grade identified 47 countable particles in the chemical and 37 in the technical concentrate test samples. Of these particles, 17 and 16 in the chemical and technical test samples, respectively, satisfied the more rigorous, previously used Mines Safety and Inspection Regulations 1995 (Western Australia [WA]) criteria, L ˃ 5 µm and D ≤ 1 µm. The majority of the countable particles were consistent with α-spodumene cleavage fragments. These results suggest elongated α-spodumene particles may pose a health risk. It is recommended the precautionary principle be applied to respirable α-spodumene particles and the identification and control of dust hazards in spodumene extraction, handling and processing industries be implemented. Full article
(This article belongs to the Section Toxicology and Public Health)
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17 pages, 1329 KiB  
Review
Asbestos and Other Hazardous Fibrous Minerals: Potential Exposure Pathways and Associated Health Risks
by Terri-Ann Berry, Elena Belluso, Ruggero Vigliaturo, Reto Gieré, Edward A. Emmett, Joseph R. Testa, Gregor Steinhorn and Shannon L. Wallis
Int. J. Environ. Res. Public Health 2022, 19(7), 4031; https://doi.org/10.3390/ijerph19074031 - 29 Mar 2022
Cited by 35 | Viewed by 7514
Abstract
There are six elongate mineral particles (EMPs) corresponding to specific dimensional and morphological criteria, known as asbestos. Responsible for health issues including asbestosis, and malignant mesothelioma, asbestos has been well researched. Despite this, significant exposure continues to occur throughout the world, potentially affecting [...] Read more.
There are six elongate mineral particles (EMPs) corresponding to specific dimensional and morphological criteria, known as asbestos. Responsible for health issues including asbestosis, and malignant mesothelioma, asbestos has been well researched. Despite this, significant exposure continues to occur throughout the world, potentially affecting 125 million people in the workplace and causing thousands of deaths annually from exposure in homes. However, there are other EMPS, such as fibrous/asbestiform erionite, that are classified as carcinogens and have been linked to cancers in areas where it has been incorporated into local building materials or released into the environment through earthmoving activities. Erionite is a more potent carcinogen than asbestos but as it is seldom used for commercial purposes, exposure pathways have been less well studied. Despite the apparent similarities between asbestos and fibrous erionite, their health risks and exposure pathways are quite different. This article examines the hazards presented by EMPs with a particular focus on fibrous erionite. It includes a discussion of the global locations of erionite and similar hazardous minerals, a comparison of the multiple exposure pathways for asbestos and fibrous erionite, a brief discussion of the confusing nomenclature associated with EMPs, and considerations of increasing global mesothelioma cases. Full article
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13 pages, 1977 KiB  
Article
Diagnostic and Prognostic Value of Three microRNAs in Environmental Asbestiform Fibers-Associated Malignant Mesothelioma
by Veronica Filetti, Carla Loreto, Luca Falzone, Claudia Lombardo, Emanuele Cannizzaro, Sergio Castorina, Caterina Ledda and Venerando Rapisarda
J. Pers. Med. 2021, 11(11), 1205; https://doi.org/10.3390/jpm11111205 - 15 Nov 2021
Cited by 16 | Viewed by 2283
Abstract
Fluoro-edenite (FE) is an asbestiform fiber identified in Biancavilla (Sicily, Italy). Environmental exposure to FE has been associated with a higher incidence of malignant mesothelioma (MM). The present study aimed to validate the predicted diagnostic significance of hsa-miR-323a-3p, hsa-miR-101-3p, and hsa-miR-20b-5p on a [...] Read more.
Fluoro-edenite (FE) is an asbestiform fiber identified in Biancavilla (Sicily, Italy). Environmental exposure to FE has been associated with a higher incidence of malignant mesothelioma (MM). The present study aimed to validate the predicted diagnostic significance of hsa-miR-323a-3p, hsa-miR-101-3p, and hsa-miR-20b-5p on a subset of MM patients exposed to FE and matched with healthy controls. For this purpose, MM tissues vs. nonmalignant pleura tissues were analyzed through droplet digital PCR (ddPCR) to evaluate differences in the expression levels of the selected miRNAs and their MM diagnostic potential. In addition, further computational analysis has been performed to establish the correlation of these miRNAs with the available online asbestos exposure data and clinic-pathological parameters to verify the potential role of these miRNAs as prognostic tools. ddPCR results showed that the three analyzed miRNAs were significantly down-regulated in MM cases vs. controls. Receiver operating characteristic (ROC) analysis revealed high specificity and sensitivity rates for both hsa-miR-323a-3p and hsa-miR-20b-5p, which thus acquire a diagnostic value for MM. In silico results showed a potential prognostic role of hsa-miR-101-3p due to a significant association of its higher expression and increased overall survival (OS) of MM patients. Full article
(This article belongs to the Special Issue Role of MicroRNA in Cancer Development and Treatment)
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21 pages, 2196 KiB  
Article
Late Inflammation Induced by Asbestiform Fibers in Mice Is Ameliorated by a Small Molecule Synthetic Lignan
by Reagan Badger, Kyewon Park, Ralph A. Pietrofesa, Melpo Christofidou-Solomidou and Kinta M. Serve
Int. J. Mol. Sci. 2021, 22(20), 10982; https://doi.org/10.3390/ijms222010982 - 12 Oct 2021
Cited by 3 | Viewed by 2666
Abstract
Exposure to Libby amphibole (LA) asbestos-like fibers is associated with increased risk of asbestosis, mesothelioma, pulmonary disease, and systemic autoimmune disease. LGM2605 is a small molecule antioxidant and free radical scavenger, with anti-inflammatory effects in various disease models. The current study aimed to [...] Read more.
Exposure to Libby amphibole (LA) asbestos-like fibers is associated with increased risk of asbestosis, mesothelioma, pulmonary disease, and systemic autoimmune disease. LGM2605 is a small molecule antioxidant and free radical scavenger, with anti-inflammatory effects in various disease models. The current study aimed to determine whether the protective effects of LGM2605 persist during the late inflammatory phase post-LA exposure. Male and female C57BL/6 mice were administered daily LGM2605 (100 mg/kg) via gel cups for 3 days before and 14 days after a 200 µg LA given via intraperitoneal (i.p.) injection. Control mice were given unsupplemented gel cups and an equivalent dose of i.p. saline. On day 14 post-LA treatment, peritoneal lavage was assessed for immune cell influx, cytokine concentrations, oxidative stress biomarkers, and immunoglobulins. During the late inflammatory phase post-LA exposure, we noted an alteration in trafficking of both innate and adaptive immune cells, increased pro-inflammatory cytokine concentrations, induction of immunoglobulin isotype switching, and increased oxidized guanine species. LGM2605 countered these changes similarly among male and female mice, ameliorating late inflammation and altering immune responses in late post-LA exposure. These data support possible efficacy of LGM2605 in the prolonged treatment of LA-associated disease and other inflammatory conditions. Full article
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15 pages, 1579 KiB  
Review
Asbestiform Amphiboles and Cleavage Fragments Analogues: Overview of Critical Dimensions, Aspect Ratios, Exposure and Health Effects
by Gaia M. Militello, Laura Gaggero and Sebastiano La Maestra
Minerals 2021, 11(5), 525; https://doi.org/10.3390/min11050525 - 16 May 2021
Cited by 21 | Viewed by 5632
Abstract
The term asbestos refers to a group of serpentine (chrysotile) and amphibole (amosite, crocidolite, anthophyllite, tremolite and actinolite) minerals with a fibrous habit. Their chemical-physical properties make them one of the most important inorganic materials for industrial purposes and technological applications. However, the [...] Read more.
The term asbestos refers to a group of serpentine (chrysotile) and amphibole (amosite, crocidolite, anthophyllite, tremolite and actinolite) minerals with a fibrous habit. Their chemical-physical properties make them one of the most important inorganic materials for industrial purposes and technological applications. However, the extraction, use and marketing of these minerals have been prohibited due to proven harmful effects, mainly involving the respiratory system. In addition to the known six minerals classified as asbestos, the natural amphiboles and serpentine polymorphs antigorite and lizardite, despite having the same composition of asbestos, do not have the same morphology. These minerals develop chemical and geometric (length > 5 μm, width < 3 μm and length: diameter > 3:1), but not morphological, analogies with asbestos, which is regulated by the WHO. The debate about their potential hazardous properties is open and ongoing; therefore, their morphological characterization has a key role in establishing a reliable asbestos hazard scenario. This review focuses on evaluating the most relevant papers, evidencing the need for a reappraisal. Different in vitro, in vivo and epidemiological studies report information about cleavage fragments with critical dimensions similar to asbestos fibres, but very few works target fragments below 5 µm in length. Breathable smaller fibres could have deleterious effects on human health and cannot be disregarded from the risk assessment process. Furthermore, a few studies suggest that the carcinogenic nature of short fibres is not excluded. This review highlights that it is worth investigating the effects of this size range of elongated mineral particles and fibres. Full article
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10 pages, 1113 KiB  
Article
Quantitative Analysis of Asbestos-Containing Materials Using Various Test Methods
by Kiho Yang, Kyu-Cheul Yoo and Jaewoo Jung
Minerals 2020, 10(6), 568; https://doi.org/10.3390/min10060568 - 24 Jun 2020
Cited by 5 | Viewed by 5204
Abstract
The advantages of X-ray powder diffraction (XRPD) analysis are its non-destructive nature, reliability, fast and easy sample preparation, and low costs. XRPD analysis has been used for mineral identification and the quantitative/qualitative determination of various types of fibrous minerals in asbestos-containing materials (ACMs). [...] Read more.
The advantages of X-ray powder diffraction (XRPD) analysis are its non-destructive nature, reliability, fast and easy sample preparation, and low costs. XRPD analysis has been used for mineral identification and the quantitative/qualitative determination of various types of fibrous minerals in asbestos-containing materials (ACMs). In order to test the detection limit of ACMs by XRPDD, standard samples with various concentrations of ACMs (0.1%, 1%, and 3%) were fabricated using three matrix materials (talc, vermiculite, and sepiolite). Asbestiform tremolite and chrysotile were identified in the XRPD profiles of the samples with 1% and 3% ACMs. Their integral intensities were positively correlated with the concentrations. However, the XRPD peak of asbestos was not found in the samples with 0.1% ACMs. Therefore, scanning and transmission electron microscopy were utilized to investigate the samples with a very low concentration of ACMs. Although the ACM concentration (0.1%) was negligible and its direct observation was time-consuming, electron microscopy allowed for the detection of asbestos in several matrix materials. Thus, a combination of XRPD and electron microscopy improve analytical performance and data reliability. Full article
(This article belongs to the Special Issue Application of Mineral-Based Amendments)
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16 pages, 4581 KiB  
Article
Mineralogical and Geochemical Characterization of Asbestiform Todorokite, Birnessite, and Ranciéite, and Their host Mn-Rich Deposits from Serra D’Aiello (Southern Italy)
by Andrea Bloise, Domenico Miriello, Rosanna De Rosa, Giovanni Vespasiano, Ilaria Fuoco, Raffaella De Luca, Eugenio Barrese and Carmine Apollaro
Fibers 2020, 8(2), 9; https://doi.org/10.3390/fib8020009 - 28 Jan 2020
Cited by 6 | Viewed by 5513
Abstract
Manganese ores, especially the oxyhydroxides in their different forms, are the dominant Mn-bearing minerals that occur in marine and terrestrial environments, where they are typically found as poorly crystalline and intermixed phases. Mn oxyhydroxides have a huge range of industrial applications and are [...] Read more.
Manganese ores, especially the oxyhydroxides in their different forms, are the dominant Mn-bearing minerals that occur in marine and terrestrial environments, where they are typically found as poorly crystalline and intermixed phases. Mn oxyhydroxides have a huge range of industrial applications and are able to exert a strong control on the mobility of trace metals. This paper reports the results of a detailed study on the Mn oxyhydroxides occurring in the manganiferous deposit outcropping in the Messinian sediments from Serra D’Aiello (Southern Italy). Nine Mn samples were characterized in detail using X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), thermogravimetry (TG), transmission electron microscopy combined with energy dispersive spectrometry (TEM/EDS), and X-ray fluorescence (XRF). The results indicated that the Mn deposit included the oxyhydroxide mineral species birnessite, todorokite, and rancièite. The size, morphology, and chemical composition of Mn oxyhydroxide samples were investigated in order to define their impact on the environment and human health. Todorokite displayed asbestiform shapes and could disperse fibers of breathable size in the air. Furthermore, since in-depth characterization of minerals within Mn deposits may be the first step toward understanding the genetic processes of manganese deposits, hypotheses about the genesis of the Mn oxyhydroxide deposits were discussed. Full article
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10 pages, 7204 KiB  
Article
The First Occurrence of Asbestiform Magnesio-Riebeckite in Schists in the Frido Unit (Pollino Unesco Global Geopark, Southern Italy)
by Salvatore Laurita and Giovanna Rizzo
Fibers 2019, 7(9), 79; https://doi.org/10.3390/fib7090079 - 31 Aug 2019
Cited by 4 | Viewed by 5543
Abstract
In this paper, new mineralogical and petrographical data of asbestiform Magnesio-riebeckite from ophiolite cropping out in the Pollino Unesco Global Geopark (southern Italy) are presented. Magnesio-riebeckite schists with HP-LT index mineral assemblage recorded metamorphic events in blueschist facies in the Frido Unit. Previous [...] Read more.
In this paper, new mineralogical and petrographical data of asbestiform Magnesio-riebeckite from ophiolite cropping out in the Pollino Unesco Global Geopark (southern Italy) are presented. Magnesio-riebeckite schists with HP-LT index mineral assemblage recorded metamorphic events in blueschist facies in the Frido Unit. Previous toxicological studies showed that asbestiform Magnesio-riebeckite species exhibited high carcinogenicity in previous intraperitoneal injection experiments with rats. The results have been obtained using different analytical techniques such as X-ray fluorescence (XRF), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), and electron probe micro analysis (EPMA). Results show that all the samples contain fibrous Magnesio-riebeckite and/or prismatic, acicular crystals in aggregates. The concentration of elements in Magnesio-riebeckite crystals is: Na2O (4.12–6.26 wt%), MgO (8.22–10.87 wt%), FeO (19.07–23.81 wt%), SiO2 (52.05–56.06 wt%), CaO (1.12–4.53 wt%), Al2O3 (1.34–1.93 wt%), and MnO (0.10–0.34 wt%). Magnesio-riebeckite crystals are documented in the Pollino Unesco Global Geopark for the first time. For this reason, the aim of this paper is the characterization of Magnesio-riebeckite to improve the knowledge of this mineral in the studied area, because the release of fibers into the environment is dangerous for human health. Full article
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12 pages, 3509 KiB  
Review
Micro-Raman Spectroscopy, a Powerful Technique Allowing Sure Identification and Complete Characterization of Asbestiform Minerals
by Caterina Rinaudo and Alessandro Croce
Appl. Sci. 2019, 9(15), 3092; https://doi.org/10.3390/app9153092 - 31 Jul 2019
Cited by 15 | Viewed by 4375
Abstract
Micro-Raman spectroscopy has been applied to fibrous minerals regulated as “asbestos”—anthophyllite, actinolite, amosite, crocidolite, tremolite, and chrysotile—responsible of severe diseases affecting mainly, but not only, the respiratory system. The technique proved to be powerful in the identification of the mineral phase and in [...] Read more.
Micro-Raman spectroscopy has been applied to fibrous minerals regulated as “asbestos”—anthophyllite, actinolite, amosite, crocidolite, tremolite, and chrysotile—responsible of severe diseases affecting mainly, but not only, the respiratory system. The technique proved to be powerful in the identification of the mineral phase and in the recognition of particles of carbonaceous materials (CMs) lying on the “asbestos” fibers surface. Also, erionite, a zeolite mineral, from different outcrops has been analyzed. To erionite has been ascribed the peak of mesothelioma noticed in Cappadocia (Turkey) during the 1970s. On the fibers, micro-Raman spectroscopy allowed to recognize many grains, micrometric in size, of iron oxy-hydroxides or potassium iron sulphate, in erionite from Oregon, or particles of CMs, in erionite from North Dakota, lying on the crystal surface. Raman spectroscopy appears therefore to be the technique allowing, without preparation of the sample, a complete characterization of the minerals and of the associated phases. Full article
(This article belongs to the Special Issue Novel Insights to Raman Spectroscopy: Advances and Prospects)
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15 pages, 5328 KiB  
Article
Grinding Test on Tremolite with Fibrous and Prismatic Habit
by Oliviero Baietto, Mariangela Diano, Giovanna Zanetti and Paola Marini
Fibers 2019, 7(6), 52; https://doi.org/10.3390/fib7060052 - 1 Jun 2019
Cited by 6 | Viewed by 5906
Abstract
The main objective of this work is the evaluation of the morphology change in tremolite particles before and after a grinding process. The crushing action simulates anthropic alteration of the rock, such as excavation in rocks containing tremolite during a tunneling operation. The [...] Read more.
The main objective of this work is the evaluation of the morphology change in tremolite particles before and after a grinding process. The crushing action simulates anthropic alteration of the rock, such as excavation in rocks containing tremolite during a tunneling operation. The crystallization habit of these amphibolic minerals can exert hazardous effects on humans. The investigated amphibolic minerals are four tremolite samples, from the Piedmont and Aosta Valley regions, with different crystallization habits. The habits can be described as asbestiform (fibrous) for longer and thinner fibers and non-asbestiform (prismatic) for prismatic fragments, also known as “cleavage” fragments. In order to identify the morphological variation before and after the grinding, both a phase contrast optical microscope (PCOM) and a scanning electron microscope (SEM) were used. The identification procedure for fibrous and prismatic elements is related to a dimensional parameter (length–diameter ratio) defined by the Health and Safety Executive. The results highlight how mineral comminution leads to a rise of prismatic fragments and, therefore, to a potentially safer situation for worker and inhabitants. Full article
(This article belongs to the Special Issue Mineral Fibres)
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