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Paolo Ballirano - One of the best experts on this subject based on the ideXlab platform.

  • crystal chemical and structural characterization of natural and cation exchanged mexican Erionite
    Minerals, 2020
    Co-Authors: Karla Quirozestrada, Paolo Ballirano, Alessandro Pacella, Miguel Angel Hernandezespinosa, Carlos Felipe, Marcos Esparzaschulz
    Abstract:

    In this work, the chemical structural characterization of the Erionite-type zeolite from Agua Prieta, Sonora, Mexico, was performed on both pristine and Na, Ca, and Mg exchanged samples in order to identify the various modifications due to cation exchange. The samples investigated were those that showed the best behaviour of CO2 and CH4 adsorption at zero coverage levels and the higher values of surface area reported in our previous studies. According to the crystal-chemical formula (Na3.44K1.96Mg0.63Ca0.62)[Al8.21Si27.79O71.85]·29.63H2O, the pristine sample has been classified as Erionite-Na. Morphological FE-SEM investigation performed on both pristine (ERIN) and Na-exchanged samples (ERINa3) showed a similar range of fiber diameters (27–37 nm). The chemical analyses of the ion-exchanged samples evidenced the upload of Ca and Mg following ion exchange with Na. Rietveld analysis results allowed the identification of the chemical structural modification caused by the ion exchange process, occurring mainly at the Ca1 site.

  • thermally induced behavior of the k exchanged Erionite a further step in understanding the structural modifications of the Erionite group upon heating
    Periodico Di Mineralogia, 2018
    Co-Authors: Paolo Ballirano, Andrea Bloise, Carlo Cremisini, Elisa Nardi, Maria Rita Montereali, Alessandro Pacella
    Abstract:

    Fibrous Erionite is a naturally occurring zeolite considered to be highly carcinogenic upon inhalation, even more than crocidolite. Since no iron is typically present in Erionite, its toxicity has been attributed to ion-exchanged Fe participating in Fenton chemistry. Recently, a study aimed at investigating possible fiber inactivation routes surprisingly showed that, despite having completely occluded all available pores with K ions, the Erionite-Na sample preserved the property to upload Fe (II) within the structure. In this work, the thermal behavior of the K-exchanged Erionite-Na was investigated by TG/ DSC and  in situ  XRPD analyses in order to provide relevant information for modeling the thermally induced behavior of the Erionite group. Rietveld refinement results evidenced a general trend of cell parameters and volume with temperature similar to that observed for Erionite-K from Rome (Oregon, USA). However, the dependence of T dehydr  and T break  from Si/Si+Al ratio observed in zeolites (high Si content favours a lower T dehydr  and a higher T break ) is not observed, possibly due to the effect of the relevant amount of large K ions dispersed within the Erionite cage, acting as reinforcing blocks for the framework. Heating produces a progressive emptying of the Ca sites, common effect previously observed in Erionite samples showing different chemistry. In addition, K1  s.s.  remains unchanged evidencing the absence of any “internal ion exchange” process, whereas  s.s.  at K2 increases in the range 438-573 K and then slowly decreases in the range 700-1218 K. Both Rietveld and DSC data suggest the motion of K ions from OW sites toward the walls of the Erionite cavity during dehydration.

  • thermal stability of woolly Erionite k and considerations about the heat induced behaviour of the Erionite group
    Minerals, 2018
    Co-Authors: Paolo Ballirano, Alessandro Pacella, Matteo Giordani, Andrea Bloise, Michele Mattioli
    Abstract:

    The thermal behavior of a woolly Erionite-K sample (Lander County, NV, USA), chemical formula (Ca2.03Na0.73K2.52Mg0.26)[Al8.22Si27.78O71.80]·35.94H2O, was investigated in the 303–1173 K thermal range by in situ X-ray powder diffraction. Present data suggest a general thermally-induced volume contraction whose magnitude increases as S i S i + A l ratio becomes smaller. An inverse correlation between S i S i + A l ratio and Tdehydr is observed because higher S i S i + A l ratio values are associated to lower dehydration temperatures. A positive dependence exists between S i S i + A l ratio and Tbreak. A higher Si content results in a greater thermal stability, in agreement with the general trend observed in zeolites. On the contrary, no correlation has been found between Tbreak and weighted ionic potential (Z/r)wt as suggested by reference data. Heating produces a general depletion of the Ca1, Ca2, Ca3, and K1 sites, which is counterbalanced by an increase of the K2 site scattering, even though the latter is not populated at RT. No “internal ion exchange” mechanism was apparently acting in the present sample differently from other Erionite samples analysed in the past. At 303 K approximately 20 e− allocated at the OW H2O sites might be assigned to (extra-framework) EF cations. Such fraction increases due to their migration from the extra-framework cation sites following the same mechanism reported in reference data.

  • the mechanism of iron binding processes in Erionite fibres
    Scientific Reports, 2017
    Co-Authors: Alessandro Pacella, Carlo Cremisini, Elisa Nardi, Maria Rita Montereali, Ida Pettiti, Paolo Ballirano
    Abstract:

    Fibrous Erionite-Na from Rome (Oregon, USA) was K-exchanged and characterized from the structural point of view. In addition, the modifications experienced after contact with a Fe(II) source were investigated for evaluating if the large potassium ions, blocking off nearly all the Erionite cavity openings, might prevent the Fe(II) binding process, which is currently assumed to be one of the reasons of the toxicity of Erionite. The K-exchanged sample had a 95% reduction of the BET surface area indicating that it behaves as a mesoporous material. Exchanged K is segregated at K2 and at OW sites commonly occupied by H2O. The latter K cations provide a relevant contribution to the reduction of the surface area. Surprisingly, despite the collapse of its surface area the sample preserves the tendency to bind Fe(II). Therefore, yet in the case of a peculiar and potentially hostile structural environment the Fe(II) ion-exchange process has essentially the same kinetics observed in a typical Erionite sample. This is a clear evidence of the very limited effect of the chemical composition of Erionite on the Fe(II) binding process and reasonably it does not play a significant role in its toxicity.

  • Geological occurrence, mineralogical characterization, and risk assessment of potentially carcinogenic Erionite in Italy.
    Journal of toxicology and environmental health. Part B Critical reviews, 2017
    Co-Authors: Matteo Giordani, Paolo Ballirano, Alessandro Pacella, Michele Mattioli, Marco Cenni, Matteo Boscardin, Laura Valentini
    Abstract:

    Erionite is a zeolite representing a well-known health hazard. In fact, exposure of humans to its fibers has been unequivocally associated with occurrence of malignant mesothelioma. For this reason, a multi-methodological approach, based upon field investigation, morphological characterization, scanning electron microscopy (SEM)/energy-dispersive spectroscopy (EDS) chemical analysis, and structure refinement through X-ray powder diffraction (XRPD), was applied to different samples of potentially carcinogenic Erionite from Northern Italy. The studied crystals have a chemical composition ranging from Erionite-Ca to Erionite-Na and display variable morphologies, varying from prismatic, through acicular and fibrous, to extremely fibrous asbestiform habits. The fibrous samples were characterized by an unusual preferred partition of aluminum (Al) at tetrahedral site T1 instead of tetrahedral site T2. Further, a mismatch between the a-parameter of Erionite-Ca and levyne-Ca that are intergrown in the asbestiform sample was detected. This misfit was coupled to a relevant micro-strain to maintain structure coherency at the boundary. Erionite occurs in 65% of the investigated sites, with an estimated quantity of 10 to 40 vol% of the associated minerals. The presence of this mineral is of concern for risk to human health, especially if one considers the vast number of quarries and mining-related activities that are operating in the zeolite host rocks. The discovery of fibrous and asbestiform Erionite in Northern Italy suggests the need for a detailed risk assessment in all Italian areas showing the same potential hazard, with specific studies such as a quantification of the potentially respirable airborne fibers and targeted epidemiological surveillance.

Umran A Dogan - One of the best experts on this subject based on the ideXlab platform.

  • micro raman spectroscopy identifies crocidolite and Erionite fibers in tissue sections
    Journal of Raman Spectroscopy, 2013
    Co-Authors: Alessandro Croce, Maya Musa, Mario Allegrina, C Rinaudo, Izzettin Y Baris, Umran A Dogan, Amy Powers, Zeyana Rivera, Pietro Bertino
    Abstract:

    Exposure to asbestos or Erionite is associated with malignant mesothelioma (MM) and other diseases. Micro-Raman spectroscopy and Variable Pressure Scanning Electron Microscopy/Energy Dispersive Spectroscopy were used to identify mineral fibers in histological sections of various tissues taken from mice injected with crocidolite asbestos and Erionite fibers. Routine diagnostic histopathological slides of biopsies from Erionite-exposed MM patients from Turkey were also analyzed. We show here that micro-Raman spectroscopy easily permits the recording of distinct Raman patterns of both crocidolite and Erionite fibers, in both murine tissues and in human biopsies. The described findings provide a new powerful and non-destructive tool to determine the type of fiber exposure in patients with MM and other mineral fiber-associated diseases. Copyright © 2013 John Wiley & Sons, Ltd.

  • Erionite exposure in north dakota and turkish villages with mesothelioma
    Proceedings of the National Academy of Sciences of the United States of America, 2011
    Co-Authors: Michele Carbone, Izzettin Y Baris, Umran A Dogan, Pietro Bertino, Brian Brass, Sabahattin Comertpay, Giovanni Gaudino, Sandro Jube, Shreya Kanodia, Charles R Partridge
    Abstract:

    Exposure to Erionite, an asbestos-like mineral, causes unprecedented rates of malignant mesothelioma (MM) mortality in some Turkish villages. Erionite deposits are present in at least 12 US states. We investigated whether increased urban development has led to Erionite exposure in the United States and after preliminary exploration, focused our studies on Dunn County, North Dakota (ND). In Dunn County, ND, we discovered that over the past three decades, more than 300 miles of roads were surfaced with Erionite-containing gravel. To determine potential health implications, we compared Erionite from the Turkish villages to that from ND. Our study evaluated airborne point exposure concentrations, examined the physical and chemical properties of Erionite, and examined the hallmarks of mesothelial cell transformation in vitro and in vivo. Airborne Erionite concentrations measured in ND along roadsides, indoors, and inside vehicles, including school buses, equaled or exceeded concentrations in Boyali, where 6.25% of all deaths are caused by MM. With the exception of outdoor samples along roadsides, ND concentrations were lower than those measured in Turkish villages with MM mortality ranging from 20 to 50%. The physical and chemical properties of Erionite from Turkey and ND are very similar and they showed identical biological activities. Considering the known 30- to 60-y latency for MM development, there is reason for concern for increased risk in ND in the future. Our findings indicate that implementation of novel preventive and early detection programs in ND and other Erionite-rich areas of the United States, similar to efforts currently being undertaken in Turkey, is warranted.

  • crystal structure and iron topochemistry of Erionite k from rome oregon u s a
    American Mineralogist, 2009
    Co-Authors: Paolo Ballirano, Umran A Dogan, Meral Dogan, Giovanni B Andreozzi
    Abstract:

    A complete crystal-chemical characterization of Erionite-K from Rome, Oregon, was obtained by combining field emission scanning electron microscopy, laboratory parallel-beam transmission powder diffraction, and 57 Fe Mossbauer spectroscopy. Rietveld refinement results evidenced that the most striking difference in comparison with the structure of Erionite-Ca is significant K at a K2 site (½, 0, 0), which is empty in Erionite-Ca. In addition, site Ca1 shows low occupancy and Ca3 is vacant. The oxidation and coordination state of Fe, whose occurrence was revealed by chemical analysis, have been clarified by exploiting room- and low-temperature 57 Fe Mossbauer spectroscopy. The majority of Fe (95%) was attributed to Fe 3+ -bearing, superparamagnetic, oxide-like nanoparticles with dimensions between 1 and 9 nm, and the remaining 5% was attributed to hematite particles with size ≥10 nm, both located on the crystal surface.

  • re evaluation and re classification of Erionite series minerals
    Environmental Geochemistry and Health, 2008
    Co-Authors: Umran A Dogan, Meral Dogan
    Abstract:

    Governments and industries have introduced regulatory measures requiring safety controls to limit asbestos exposure of the general public and asbestos workers. Although Erionite is a more potent health hazard mineral than asbestos, it has received far less attention. Precise definition of Erionite, types of these fibrous minerals, and most importantly, characterization requirements still raise questions and often lead to arguments and even legal disputes. Many bulk Erionite samples used in animal and cell experiments for carcinogenicity are not mineralogically pure. To test this hypothesis, we characterized two Erionite standards from Rome, Oregon, and Pine Valley, Nevada, USA. These standards were characterized quantitatively using modern analytical techniques, and one of them, the Erionite standard from Rome, Oregon, passed the required tests for positive identification, but the other, the Erionite standard from Pine Valley, Nevada, did not. Furthermore, we observed ambiguous definitions, incorrect identifications, and inaccurate reporting of clinical investigations. To address this problem, we established characterization guidelines for positive identification of Erionite using a modified balance error formula, and we re-evaluated and re-classified published Erionite data from the literature as Erionite-Ca, Erionite-Na, and Erionite-K. If data did not pass either the E% or Mg-content test, then we propose that reference to them in the literature be disregarded. Erionite requires special attention from the mineralogical community to help establish its true carcinogenetic properties. We believe that the characterization guidelines established in this paper will contribute to setting up rules and regulations for evaluation of Erionite by regulatory agencies.

  • Erionite series minerals mineralogical and carcinogenic properties
    Environmental Geochemistry and Health, 2008
    Co-Authors: Umran A Dogan, Meral Dogan, John A Hoskins
    Abstract:

    Erionite is a human and animal carcinogen and one of the most toxic minerals known. Erionite deposits have been reported in many countries; however, it is only in the area of three villages of Cappadocia, Turkey, that environmental exposure to Erionite has been demonstrated to be the cause of an epidemic of the disease mesothelioma. In the USA, no cases of mesothelioma have been reliably proven to be the result of Erionite exposure, though the possibility exists. Erionite samples from three villages of the Cappadocia region were characterized mineralogically and compared with three different standards from the USA. Micro morphological details of Erionite minerals using a high-resolution field-emission SEM showed that microstructures of “bundles”, “fibers”, and “fibrils” are important physical properties of fibrous Erionite minerals. Typical lung burden of Erionite and asbestos fibers were compared in terms of number of fibers. Assuming the lung burden of fibers in a human mesothelioma victim is about 1 mg, and the hazardous fibers are approximately 1 μm in diameter and 10 μm long, that milligram contains approximately 40 million asbestos and 50 million Erionite fibers. These microstructures of Erionite minerals draw attention to the concepts of surface area or surface-area-to-volume ratio and their relationship to the carcinogenicity of the mineral. The larger surface area creates a wider platform for mineral–cell interaction and thus more possibilities of proliferative transformation of mesothelial cells. Consequently, understanding the exact mineralogical properties will help determination of the true carcinogenic mechanism(s) of the mineral for prevention and possibly treatment of malignant mesothelioma.

Alessandro F Gualtieri - One of the best experts on this subject based on the ideXlab platform.

  • biodurability and release of metals during the dissolution of chrysotile crocidolite and fibrous Erionite
    Environmental Research, 2019
    Co-Authors: Alessandro F Gualtieri, Gigliola Lusvardi, Alessandro Zoboli, Dario Di Giuseppe, Magdalena Lassinantti Gualtieri
    Abstract:

    Abstract Background The mechanisms by which mineral fibers induce adverse effects in vivo are still not well understood. The mechanisms of fiber dissolution in the lungs and subsequent release of metals in the extracellular/intracellular environment must be taken into account. Aim For the first time, the kinetics of release of metals during the acellular in vitro dissolution of chrysotile, crocidolite and fibrous Erionite were determined. Methods In vitro acellular dissolution of chrysotile, crocidolite, and fibrous Erionite-Na was conducted using a solution mimicking the phagolysosome environment active during the phagocytosis process (pH=4.5, at 37 °C). The kinetics of release of a representative selection of metals were determined over a period of three months. Results Despite the fact that the difference in Fe content between chrysotile and crocidolite is one order of magnitude, the much faster dissolution rate of chrysotile compared to crocidolite prompts greater release of available active surface Fe in the first weeks of the dissolution experiment and comparable amounts after 90 d. Such active iron may promote the formation of toxic hydroxyl radicals. The fast release of metals like Cr, Ni and Mn from chrysotile is also a source of concern whereas the release of V in solution is negligible. Conclusion Because chrysotile undergoes fast dissolution with respect to crocidolite and fibrous Erionite, it behaves like a carrier that releases its metals’ cargo in the lung environment, mimicking the phenomenon that explains the toxicity of nanoparticles. Hence, the toxicity paradigm of a non biodurable fiber like chrysotile should also take into account the release of toxic metals in the intracellular/extracellular medium during the rapid dissolution process.

  • In vitro acellular dissolution of mineral fibres: A comparative study.
    Scientific Reports, 2018
    Co-Authors: Alessandro F Gualtieri, Simone Pollastri, Nicola Bursi Gandolfi, Nicola Bursi Gandolfi, Simone Pollastri, Magdalena Lassinantti Gualtieri
    Abstract:

    The study of the mechanisms by which mineral fibres promote adverse effects in both animals and humans is a hot topic of multidisciplinary research with many aspects that still need to be elucidated. Besides length and diameter, a key parameter that determines the toxicity/pathogenicity of a fibre is biopersistence, one component of which is biodurability. In this paper, biodurability of mineral fibres of social and economic importance (chrysotile, amphibole asbestos and fibrous Erionite) has been determined for the first time in a systematic comparative way from in vitro acellular dissolution experiments. Dissolution was possible using the Gamble solution as simulated lung fluid (pH = 4 and at body temperature) so to reproduce the macrophage phagolysosome environment. The investigated mineral fibres display very different dissolution rates. For a 0.25 μm thick fibre, the calculated dissolution time of chrysotile is in the range 94–177 days, very short if compared to that of amphibole fibres (49–245 years), and fibrous Erionite (181 years). Diffraction and SEM data on the dissolution products evidence that chrysotile rapidly undergoes amorphization with the formation of a nanophasic silica-rich fibrous metastable pseudomorph as first dissolution step whereas amphibole asbestos and fibrous Erionite show minor signs of dissolution even after 9–12 months.

  • new insights into the toxicity of mineral fibres a combined in situ synchrotron μ xrd and hr tem study of chrysotile crocidolite and Erionite fibres found in the tissues of sprague dawley rats
    Toxicology Letters, 2017
    Co-Authors: Alessandro F Gualtieri, Nicola Bursi Gandolfi, Simone Pollastri, Kilian Pollok, Falko Langenhorst, Manfred Burghammer, Eva Tibaldi, Fiorella Belpoggi, Ruggero Vigliaturo, Goran Dražic
    Abstract:

    Abstract Along the line of the recent research topic aimed at understanding the in vivo activity of mineral fibres and their mechanisms of toxicity, this work describes the morpho-chemical characteristics of the mineral fibres found in the tissues of Sprague-Dawley rats subjected to intraperitoneal/intrapleural injection of UICC chrysotile, UICC crocidolite and Erionite-Na from Nevada (USA). The fibres are studied with in situ synchrotron powder diffraction and high resolution transmission electron microscopy to improve our understanding of the mechanisms of toxicity of these mineral fibres. In contact with the tissues of the rats, chrysotile fibres are prone to dissolve, with leaching of Mg and production of a silica rich relict. On the other hand, crocidolite and Erionite-Na fibres are stable even for very long contact times within the tissues of the rats, showing just a thin dissolution amorphous halo. These findings support the model of a lower biopersistence of chrysotile with respect to crocidolite and Erionite-Na but the formation of a silica-rich fibrous residue after the pseudo-amorphization of chrysotile may justify a higher cytotoxic potential and intense inflammatory activity of chrysotile in the short term in contact with the lung tissues.

  • where is iron in Erionite a multidisciplinary study on fibrous Erionite na from jersey nevada usa
    Scientific Reports, 2016
    Co-Authors: Alessandro F Gualtieri, Nicola Bursi Gandolfi, Simone Pollastri, Kilian Pollok, Falko Langenhorst
    Abstract:

    Fibrous Erionite is a mineral fibre of great concern but to date mechanisms by which it induces cyto- and geno-toxic damage, and especially the role of iron associated to this zeolite species, remain poorly understood. One of the reasons is that we still don’t know exactly where iron is in natural Erionite. This work is focused on fibrous Erionite-Na from Jersey (Nevada, USA) and attempts to draw a general model of occurrence of iron in Erionite and relationship with toxicity mechanisms. It was found that iron is present as 6-fold coordinated Fe3+ not part of the zeolite structure. The heterogeneous nature of the sample was revealed as receptacle of different iron-bearing impurities (amorphous iron-rich nanoparticles, micro-particles of iron oxides/hydroxides, and flakes of nontronite). If iron is not part of the structure, its role should be considered irrelevant for Erionite toxicity, and other factors like biopersistence should be invoked. An alternative perspective to the proposed model is that iron rich nano-particles and nontronite dissolve in the intracellular acidic environment, leaving a residue of iron atoms at specific surface sites anchored to the windows of the zeolite channels. These sites may be active later as low nuclearity groups.

  • assessment of asbestos body formation by high resolution feg sem after exposure of sprague dawley rats to chrysotile crocidolite or Erionite
    Journal of Hazardous Materials, 2016
    Co-Authors: Nicola Bursi Gandolfi, Alessandro F Gualtieri, Simone Pollastri, Eva Tibaldi, Fiorella Belpoggi
    Abstract:

    Abstract This work presents a comparative FEG–SEM study of the morphological and chemical characteristics of both asbestos bodies and fibres found in the tissues of Sprague–Dawley rats subjected to intraperitoneal or intrapleural injection of UICC chrysotile, UICC crocidolite and Erionite from Jersey, Nevada (USA), with monitoring up to 3 years after exposure. Due to unequal dosing based on number of fibres per mass for chrysotile with respect to crocidolite and Erionite, excessive fibre burden and fibre aggregation during injection that especially for chrysotile would likely not represent what humans would be exposed to, caution must be taken in extrapolating our results based on instillation in experimental animals to human inhalation. Notwithstanding, the results of this study may help to better understand the mechanism of formation of asbestos bodies. For chrysotile and crocidolite, asbestos bodies are systematically formed on long asbestos fibres. The number of coated fibres is only 3.3% in chrysotile inoculated tissues. In UICC crocidolite, Mg, Si, and Fe are associated with the fibres whereas Fe, P and Ca are associated with the coating. Even for crocidolite, most of the observed fibres are uncoated as coated fibres are about 5.7%. Asbestos bodies do not form on Erionite fibres. The crystal habit, crystallinity and chemistry of all fibre species do not change with contact time, with the exception of chrysotile which shows signs of leaching of Mg. A model for the formation of asbestos bodies from mineral fibres is postulated. Because the three fibre species show limited signs of dissolution in the tissue, they cannot act as source of elements (primarily Fe, P and Ca) promoting nucleation and growth of asbestos bodies. Hence, the limited number of coated fibres should be due to the lack of nutrients or organic nature.

Georgia Cametti - One of the best experts on this subject based on the ideXlab platform.

  • crystal structure of ag exchanged levyne intergrown with Erionite single crystal x ray diffraction and molecular dynamics simulations
    American Mineralogist, 2020
    Co-Authors: Georgia Cametti, Sergey V Churakov
    Abstract:

    The modification of natural zeolites via ion exchange is an efficient technique used to improve their performances and tune their properties for specific applications. In this study, a natural levyne-Ca intergrown with Erionite was fully exchanged by Ag+ and its structure (with idealized chemical composition Ag6(Si,Al)18O36∙18H2O) was investigated by combining a theoretical and experimental approach. Single crystal X-ray diffraction data demonstrated that Ag-levyne maintained the R-3m space group, characteristic of the natural levyne. Ag ions distribute over partially occupied sites along the three-fold axis and, differently from the pristine material, at the wall of the 8-membered ring window of the lev cavity. The lack of approximately 30% of Ag ions that could not be located by the structural refinement is ascribed to the strong disorder of the extraframework occupants. The structural results obtained by molecular dynamics simulations are in overall agreement with the experimental data and showed that, on average, Ag+ is surrounded by approximately 2 H2O and 1 framework oxygen at distances between 2.43 and 2.6 A. Molecular dynamic trajectories indicate that the occurrence of silver inside the D6R cage depends on the water content: silver occupancy of D6R cages is estimated to be 83%, 30%, and 0% when the structure contains 3, 2.5, and 2 H2O per Ag ion, respectively. The cation-exchange process, as demonstrated by SEM-EDS analyses affects the intergrown Erionite as well. A structural characterization of the Ag-Erionite phase (with dimension less than 100 μm) was possible by means of a CuKα micro-focus source: structure solution pointed to P63/mmm space group, indicating no change with respect to natural Erionite. In agreement with previous studies, K ions in the cancrinite cage could not be exchanged, whereas Ag+ is found in the eri cavity.

  • a deep look into Erionite fibres an electron microscopy investigation of their self assembly
    Scientific Reports, 2015
    Co-Authors: Roberto Matassa, Alessandro Pacella, Georgia Cametti, Giuseppe Familiari, Michela Relucenti, Ezio Battaglione, Clive Downing, Paolo Ballirano
    Abstract:

    The exposure of humans to Erionite fibres of appropriate morphology and dimension has been unambiguously linked to the occurrence of Malignant Mesothelioma. For this reason, a detailed morpho-structural investigation through Electron Microscopy techniques has been performed on Erionite samples collected at two different localities, Durkee (ED) and Rome (ER), Oregon, USA. The sample from Rome has been also investigated after a prolonged leaching with Gamble’s solution (ER4G) in order to evaluate the possible occurrence of morpho-structural modifications induced by this Simulated-Lung-Fluid (SLF). Here we report how the micrometric Erionite fibres evolve in irregular ribbon- or rod-like bundles as a function of different nano-structural features. The reasons for the observed morphological variability have been explained by considering the structural defects located at ED surface fibrils (bi-dimensional ribbons) and the presence of nontronite, an iron-bearing clay mineral embedding the ER fibrils (mono-dimensional rods). ER4G shows a decrease in width of the rod-like fibres due to their partial digestion by SLF leaching, which synchronously dissolves nontronite. The reported results represent a valuable background toward the full comprehension of the morphological mechanisms responsible for potentially damage of lung tissue through the potential relocation of fibers to extrapulmonary sites, increasing the carcinogenic risk to humans.

  • fe ii segregation at a specific crystallographic site of fibrous Erionite a first step toward the understanding of the mechanisms inducing its carcinogenicity
    Microporous and Mesoporous Materials, 2015
    Co-Authors: Paolo Ballirano, Alessandro Pacella, Carlo Cremisini, Elisa Nardi, Georgia Cametti, Marzia Fantauzzi, Davide Atzei, Antonella Rossi
    Abstract:

    Abstract Two samples of fibrous Erionite from different localities of Oregon, USA were suspended in FeCl2 solutions at different concentrations, at pH ca. 5, in anaerobic conditions. Comparison between released and acquired charges under the form of Fe confirms that Erionite binds Fe (II) by ion exchange with the extra framework (EF) cations, mainly Na. The Fe (II) binding process exhibited by both studied samples here investigated indicates a direct correlation between the extent of the ion-exchange process and the Fe (II) concentration of the solution used for fibres incubation. In the sample from Rome no further Fe (II) acquisition was observed for concentrations exceeding 500 μM FeCl2. XPS investigation revealed that, when comparing surface and bulk composition of the samples, no Fe enrichment of the fibre surface was observed. Moreover, the location of Fe (II) within the Erionite cage has been devised by combining chemical and structural data. Results highlight that, for both samples, Fe (II) is fixed at the Ca3 site being six-fold coordinated to water molecules. The occurrence of Fe (II) within the Erionite cage causes a gradual migration of the other EF cations and in addition, induces a small rearrangement of the water molecules positions. It is worth mentioning that, in Fe-loaded zeolites at rather low Fe content, the Fe sites with very low nuclearity, located in well-defined crystallographic positions, represent the active sites for the formation of reactive oxygen species. Therefore, identification of segregation of Fe (II) at Ca3, which is coupled with the high surface area of Erionite, provides very important information for the understanding of the molecular mechanism/s inducing its strong carcinogenicity.

  • crystal chemical and structural modifications of Erionite fibers leached with simulated lung fluids
    American Mineralogist, 2015
    Co-Authors: Paolo Ballirano, Georgia Cametti
    Abstract:

    Inhalation of Erionite has been proven to be the cause of the extended epidemic of malignant mesothelioma occurring in Central Anatolia, Turkey, and of cases of lung diseases in the U.S.A. Its carcinogenicity is three orders of magnitude greater than that of regulated asbestos. Here we report the results of the investigation of the structural and crystal chemical modifications occurring in Erionite leached with artificial lysosomal fluid (ALF) and Gamble’s solution. ALF leaching produces a migration of Na+ ions from Ca1 to Ca2 extraframework cationic site, without the occurrence of any significant modification of the chemical composition of the fibers. In contrast, leaching with Gamble’s solution induces a complex ionic-exchange process resulting in a temporary partial replacement of Na+ by Ca2+, coming from the fluid, which is fixed at a third Ca3 cationic site. Subsequently, the exchange process reverses. In fact, Ca2+ is removed from Ca3 and Na+ migrates back to Ca1, the structure being indistinguishable from the starting, unleached material. Such processes seem to be accompanied by a progressive amorphization of fibers. Present data could provide valuable background for a more detailed comprehension of the morphostructural/biological activity relationships inducing pathogenicity.

  • new morphological chemical and structural data of woolly Erionite na from durkee oregon u s a
    American Mineralogist, 2013
    Co-Authors: Georgia Cametti, Alessandro Pacella, Francesco Mura, M Rossi, Paolo Ballirano
    Abstract:

    A detailed morphological, crystal-chemical, and structural characterization of Erionite from the type locality of Durkee, Oregon, has been carried out by combining field emission scanning electron microscopy (FESEM) and laboratory parallel-beam transmission X-ray powder diffraction (XRPD). According to the crystal-chemical formula (Na 5.38 K 1.99 Mg 0.24 )[Al 7.66 Si 28.34 O 72.09 ]·29.83H 2 O, the sample has been classified as Erionite-Na. The Rietveld refinement has indicated that the extraframework cations are located at three Ca1, Ca2, and Ca3 sites, the first one containing all available Mg. Moreover, the absence of the additional K2 site found in both dehydrated Erionite and Erionite-K has been demonstrated for this Erionite sample. Furthermore, our results revealed the absence of Fe and Ca although previous investigations have reported the presence of a variable content of both these elements in Erionite samples from Durkee. This is relevant information because it is well known from amphibole asbestos that Fe 2+ has been claimed to be one of the causes of carcinogenesis by participating in Fenton chemistry and producing free radicals.

Meral Dogan - One of the best experts on this subject based on the ideXlab platform.

  • potential carcinogenic Erionite from lessini mounts ne italy morphological mineralogical and chemical characterization
    Journal of Toxicology and Environmental Health, 2016
    Co-Authors: Matteo Giordani, Michele Mattioli, Meral Dogan, Ahmet Umran Dogan
    Abstract:

    Exposure of humans to Erionite fibers of suitable morphology and dimension has been unambiguously linked to the occurrence of malignant mesothelioma. For this reason, a morphological, morphometrical, mineralogical, and chemical investigation was performed on two representative samples of potential carcinogenic, fibrous Erionite from Lessini Mounts, northeastern (NE) Italy, which has not apparently been examined previously. The first sample is Erionite-Ca with an extremely fibrous, hair-like and flexible appearance, and growth in intimate association with levyne. The second sample is Erionite-Ca with prismatic to acicular crystals and rigid behavior, enriched in K(+) and Ca(2+) extra-framework cations. Although Erionite is a nominally Fe-free phase, iron (Fe) was detected in low amounts in all the analyzed crystals. In both the investigated samples, Erionite is present as individual fibers of respirable size. Considering that the toxicity and carcinogenic potential of Erionite is associated with its size parameters, together with its in vivo durability and high surface area, most of the investigated fibers may also be potentially carcinogenic. The presence of Erionite in extensively quarried and largely employed volcanic rocks, suggesting the need for detailed health-based studies in the region.

  • health implications of environmental exposures to Erionite in the u s and turkey
    ISEE Conference Abstracts, 2015
    Co-Authors: Aubrey Miller, Meral Dogan, Brian Brass, Umran Dogan, Gregory Meeker, Michele Carbone
    Abstract:

    Introduction: Naturally occurring asbestos (NOA) and other fibrous mineral exposures have been associated with disease throughout the world. This is especially true of Erionite which has caused unp...

  • quantitative characterization of the mesothelioma inducing Erionite series minerals by transmission electron microscopy and energy dispersive spectroscopy
    Scanning, 2012
    Co-Authors: Meral Dogan
    Abstract:

    Air-collected Erionite series minerals from Cappadocia region of Turkey were characterized quantitatively by using transmission electron microscopy (TEM) equipped with energy dispersive spectroscopy (EDS). Field emission scanning electron microscopy aided identification of fibrous minerals. Quantitative characterization guidelines for positive identification of Erionites proposed by Dogan and Dogan (2008) was applied and the modified balance error formula (E%<10) and Mg-content test <0.80 were performed for each analysis. Erionite species computation showed that the mineral is Erionite-K and a mean chemical formula is proposed based upon the TEM-EDS results. Among the 60 analyses, 11 passed E% test (18.3%), 33 passed Mg-content test (55.0%), and only 3 passed both E% and Mg-content tests (5.0%). This shows difficulty of quantitative characterization of the Erionite series minerals. However, as Erionite is the most carcinogenic mineral known and is classified by IARC as a Group-I (human) carcinogen, it requires special attention from the mineralogical community to help establish its true mineralogical properties. Quantitatively characterized Erionite data are very scarce in literature. Correctly identified Erionite mineral types will be useful to medical researchers in their search to find a possible cure for the deadly disease of mesothelioma. SCANNING 34: 37–42, 2012. © 2011 Wiley Periodicals, Inc.

  • crystal structure and iron topochemistry of Erionite k from rome oregon u s a
    American Mineralogist, 2009
    Co-Authors: Paolo Ballirano, Umran A Dogan, Meral Dogan, Giovanni B Andreozzi
    Abstract:

    A complete crystal-chemical characterization of Erionite-K from Rome, Oregon, was obtained by combining field emission scanning electron microscopy, laboratory parallel-beam transmission powder diffraction, and 57 Fe Mossbauer spectroscopy. Rietveld refinement results evidenced that the most striking difference in comparison with the structure of Erionite-Ca is significant K at a K2 site (½, 0, 0), which is empty in Erionite-Ca. In addition, site Ca1 shows low occupancy and Ca3 is vacant. The oxidation and coordination state of Fe, whose occurrence was revealed by chemical analysis, have been clarified by exploiting room- and low-temperature 57 Fe Mossbauer spectroscopy. The majority of Fe (95%) was attributed to Fe 3+ -bearing, superparamagnetic, oxide-like nanoparticles with dimensions between 1 and 9 nm, and the remaining 5% was attributed to hematite particles with size ≥10 nm, both located on the crystal surface.

  • re evaluation and re classification of Erionite series minerals
    Environmental Geochemistry and Health, 2008
    Co-Authors: Umran A Dogan, Meral Dogan
    Abstract:

    Governments and industries have introduced regulatory measures requiring safety controls to limit asbestos exposure of the general public and asbestos workers. Although Erionite is a more potent health hazard mineral than asbestos, it has received far less attention. Precise definition of Erionite, types of these fibrous minerals, and most importantly, characterization requirements still raise questions and often lead to arguments and even legal disputes. Many bulk Erionite samples used in animal and cell experiments for carcinogenicity are not mineralogically pure. To test this hypothesis, we characterized two Erionite standards from Rome, Oregon, and Pine Valley, Nevada, USA. These standards were characterized quantitatively using modern analytical techniques, and one of them, the Erionite standard from Rome, Oregon, passed the required tests for positive identification, but the other, the Erionite standard from Pine Valley, Nevada, did not. Furthermore, we observed ambiguous definitions, incorrect identifications, and inaccurate reporting of clinical investigations. To address this problem, we established characterization guidelines for positive identification of Erionite using a modified balance error formula, and we re-evaluated and re-classified published Erionite data from the literature as Erionite-Ca, Erionite-Na, and Erionite-K. If data did not pass either the E% or Mg-content test, then we propose that reference to them in the literature be disregarded. Erionite requires special attention from the mineralogical community to help establish its true carcinogenetic properties. We believe that the characterization guidelines established in this paper will contribute to setting up rules and regulations for evaluation of Erionite by regulatory agencies.