Department of Pure and Applied Sciences Dipartimento di Scienze Pure e Applicate Philosophy Degree in Basic Sciences and Applications Curriculum Earth Sciences Corso di Dottorato in Scienze di Base e Applicazioni Curriculum Scienze della Terra XXIX Ciclo Titolo della tesi: Mineralogical study of the fibrous zeolites erionite and offretite and hazard assessment Studio mineralogico delle zeoliti fibrose erionite ed offretite e valutazione della pericolosità Settore Scientifico Disciplinare SSD: GEO/06 Dottorando Relatore Matteo Giordani Prof. Michele Mattioli Anno Accademico 2015/2016 Department of Pure and Applied Sciences Dipartimento di Scienze Pure e Applicate Philosophy Degree in Basic Sciences and Applications Curriculum Earth Sciences Corso di Dottorato in Scienze di Base e Applicazioni Curriculum Scienze della Terra XXIX Ciclo Titolo della tesi: Mineralogical study of the fibrous zeolites erionite and offretite and hazard assessment Studio mineralogico delle zeoliti fibrose erionite ed offretite e valutazione della pericolosità Settore Scientifico Disciplinare SSD: GEO/06 Dottorando Relatore Matteo Giordani Prof. Michele Mattioli Anno Accademico 2015/2016 A mio padre List of contents 1. GENERAL INTRODUCTION AND SUMMARY 1 Introduzione generale e Sommario 3 2. POTENTIALLY CARCINOGENIC ERIONITE FROM LESSINI MOUNTAINS, NE ITALY: MORPHOLOGICAL, MINERALOGICAL AND CHEMICAL CHARACTERIZATION 2.1 Introduction 7 2.2 Mineralogical background 8 2.3 Materials and methods 9 2.3.1 Materials 9 2.3.2 Environmental Scanning Electron Microscope (ESEM) 9 2.3.3 Electron Micro Probe Analysis (EMPA) 10 2.3.4 X-ray Powder Diffraction (XRPD) 11 2.4 Results 11 2.4.1 Morphology 11 2.4.2 Mineralogical composition 13 2.4.3 Morphometry 14 2.4.4 Chemical data 15 2.5 Discussion 15 2.5.1 Environmental occurrence of erionite and risk assessment in Italy 19 2.6 Conclusion 20 3. GEOLOGICAL OCCURRENCE, MINERALOGICAL CHARACTERIZATION AND RISK ASSESSMENT OF POTENTIALLY CARCINOGENIC ERIONITE IN ITALY 3.1 Introduction 22 3.2 Background 23 3.2.1 Mineralogy 23 3.2.2 Erionite geology 23 3.2.3 Erionite health risks 24 3.3 Field description and materials 25 3.4 Analytical methods 27 3.4.1 Scanning Electron Microscopy (SEM) 27 3.4.2 X-Ray Powder Diffraction (XRPD) 28 3.5 Results and discussion 28 3.5.1 Morphology 28 3.5.2 Chemistry 32 3.5.3 Structure of the fibrous samples 33 3.5.4 Erionite occurrences and risk assessment in Italy 37 3.6 Concluding remarks 40 4. PRISMATIC TO ASBESTIFORM OFFRETITE FROM NORTHERN ITALY: NEW MORPHOLOGICAL AND CHEMICAL DATA OF A POTENTIALLY HAZARDOUS ZEOLITE 4.1 Introduction 42 4.2 Materials and methods 44 4.2.1 Materials 44 4.2.2 Scanning Electron Microscopy (SEM) 44 4.2.3 X-ray Powder Diffraction (XRPD) 45 4.3 Results 45 4.3.1 Morphology 45 4.3.2 Mineralogical composition 47 4.3.3 Chemical data 48 4.4 Discussion and conclusions 49 5. MORPHO-CHEMICAL CHARACTERIZATION AND SURFACE PROPERTIES OF CARCINOGENIC ZEOLITE FIBERS 5.1 Introduction 52 5.2 Experimental 54 5.2.1 Materials 54 5.2.2 Methods 54 5.2.2.1 SEM-EDS and EPMA 54 5.2.2.2 XRPD 54 5.2.2.3 Surface area-BET 54 5.2.2.4 EPR 54 5.2.2.5 Simulation of the EPR spectra 54 5.3 Results and discussion 55 5.3.1 Morphological data 55 5.3.2 Mineralogical data 55 5.3.3 Chemical data 58 5.3.4 Specific surface area analysis 60 5.3.5 EPR analysis 61 5.4 Conclusions 64 6. EPR AND TEM STUDY OF THE INTERACTIONS BETWEEN ASBESTIFORM ZEOLITE FIBERS AND MODEL MEMBRANES 6.1 Introduction 66 6.2 Experimental 69 6.2.1 Materials 69 6.2.2 Methods 70 6.2.2.1 Electron Paramagnetic Resonance (EPR) 70 6.2.2.2 Transmission Electron Microscopy (TEM) 70 6.3 Results and discussion 70 6.3.1 EPR analysis 70 6.3.1.1 CTAB micelles 70 6.3.1.2 Lecithin liposomes 74 6.3.1.3 DMPC Liposomes 76 6.3.1.4 TEM Results 77 6.4 Conclusion 79 REFERENCES 81 ACKNOWLEDGEMENTS 94 SUPPLEMENTARY MATERIALS Supplementary material Chapter 3 95 Supplementary material Chapter 5 102 Supplementary material Chapter 6 110 General introduction and summary Chapter 1 Chapter 1 GENERAL INTRODUCTION AND SUMMARY Several fibrous minerals are known in nature, mineral (IARC 1987; 2012). Recently, a some of which have chemical and physical growing concern has developed regarding the characteristics very useful in various industri- potential risks associated with environmental al processes and applications. However, some and occupational exposures to erionite in of them are considered highly hazardous to Turkey (Carbone et al., 2011), in the United human health, because of their capability to States (Saini-Eidukat and Triplett, 2014), in divide into inhalable size fibers, together with Mexico (Ortega-Guerrero and Carrasco- their biopersistence in the lungs. This is the Nùñez, 2014) and possibly in Iran (Ilgren et case, for example, of the well-known asbes- al., 2015). Then, it is very likely that this tos. Nevertheless, there are many other fi- problem could also be extended to other coun- brous minerals with physical and chemical tries in the future. characteristics very similar with those of as- The main mechanisms by which inhaled fi- bestos, which have not been sufficiently in- bres of erionite, as well as other fibrous par- vestigated. For some of them, such as ticulates, induce pathological changes com- attapulgite, palygorskyte, byssolite, picrolite, prise the following factors: (a) physical fea- sepiolite, thomsonite, scolecite, mesolite, nat- tures of the fibrous mineral particles such as rolite and offretite, the dangerousness has not diameter, length and aspect ratio; (b) chemi- yet been neither confirmed nor denied. For cal-mineralogical features (fibre type, chemi- others fibrous minerals (e.g. jamesonite, cal composition and surface reactivity); (c) carlostauranite, wollastonite, nemalite, the ability to generate reactive oxygen species clinoptilolite, phillipsite, mordenite) prelimi- (ROS); and (d) the biopersistence. Despite of nary studies seem to point out some toxic ef- the great number of researches, the relation- fects. Lastly, other fibrous phases have al- ships among mineralogical features and bio- ready been well studied and are currently con- logical activity of erionite have not been fully sidered carcinogenic if inhaled, such as fluo- understood and there are no systematic stud- ro-edenite, balangeroite, riebeckite, grunerite ies on the distribution of erionite or other sim- and erionite. ilar fibrous zeolites in the environment. Several fibrous minerals belong to the zeolite Moreover, there is another zeolite, named group. Zeolites occurs worldwide and are offretite, which is closely related both struc- widely used in materials for the construction turally and chemically to erionite. Despite industry, in paper, in agriculture and in other commonly occurring as prisms, offretite has applications. Therefore, potential exposure to also been found under asbestiform habit, the fibres may occur during the mining, pro- meaning that the morphology of its crystals duction and use of the fibrous zeolites (IARC, has not yet been fully known and many min- 1997). In particular, the exposure of erionite eralogical aspects are still to be discovered. fibres to humans has been unambiguously Due to these similarities and to the possible linked to malignant mesothelioma (Baris et intergrowth, the distinction between erionite al., 1978), and in vivo studies have demon- and offretite can be hampered. To date, there strated that erionite is significantly more tu- are no studies regarding a potentially hazard morigenic than asbestos (Coffin et al., 1992). of offretite fibers and it is unclear whether the For these reasons, the International Agency mineralogical distinction between erionite and for Research on Cancer (IARC) has referred offretite has any health implications. erionite as a Class 1 carcinogen, and at pre- The gap of knowledge of the fibrous zeolites sent is considered as the most carcinogenic erionite and offretite has been the starting 1 General introduction and summary Chapter 1 point for the development of the present PhD field investigation, morphological characteri- project. This work is based on a detailed min- zation, SEM/EDS chemical analysis and eralogical study with determination of mor- structure refinement through X-ray powder phological and morphometric characteristics, diffraction was applied to different samples of physical properties, chemical compositions potentially carcinogenic erionite. The chemi- and crystalline structures of selected samples cal composition of the studied crystals ranges of both erionite and offretite zeolites. Succes- from erionite-Ca to erionite-Na, and they sively, these samples have been used to carry show variable morphologies, ranging from out in-vitro experiments to assess the level of prismatic, through acicular and fibrous, to ex- reactivity and transformation that such fibers tremely fibrous asbestiform habits. The fi- may induce to micelles and membranes in brous samples are characterized by an unusual contact with them, and therefore, indirectly preferred partition of Al at T1 instead of T2 the possibility of leading to asbestos-related site. Moreover, a mismatch between the a- lung diseases. parameter of erionite-Ca and levyne-Ca that are intergrown in the asbestiform sample has On the basis of this starting point, the Thesis been detected. This misfit is coupled to a rel- has been organized in 6 Chapters. evant microstrain to maintain structure coher- This Chapter (Chapter 1) is dedicated to a ency at the boundary. Erionite occurs in 65% general introduction illustrating the major of the investigated sites, with an estimated aims of this project and the structure- amount from 10 to 40 vol.% of the associated organization of the Thesis. A brief summary minerals. These amounts are not negligible with main results of each chapter is also pre- for the human health, particularly if the great sented.