Asbestiform Minerals Associated with Chrysotile from the Western Alps (Piedmont - Italy): Chemical Characteristics and Possible Related Toxicity

ABSTRACT The natural occurrence of asbestos (NOA) in rocks and soil has been known for many years in several areas of the world, differently from the natural presence of asbestiform minerals. In Italy, the mapping of NOA is mandatory according to the 2001 and 2003 regulations. An investigation, not yet concluded, has revealed that in Italy, NOA is represented by chrysotile and tremolite asbestos with minor amounts of actinolite asbestos and anthophyllite asbestos. A field survey conducted in the Italian Western Alps (IWA), dealing with the natural occurrence of asbestiform minerals non-asbestos classified and not regulated, started many years ago and is still ongoing. It revealed that the following kinds of asbestiform silicates are present (in decreasing order of frequency): asbestiform polygonal serpentine and asbestiform antigorite, asbestiform diopside, asbestiform carlosturanite, asbestiform forsterite, asbestiform sepiolite, asbestiform balangeroite, and asbestiform talc. The asbestiform non-silicates brugnatellite and brucite have been rarely detected. Outside the IWA, asbestiform zeolite (erionite and offretite), asbestiform sodium amphibole (fluoro-edenite), and a few other asbestiform silicates have been also detected. For some asbestiform minerals, the identification is problematic and needs the use of transmission electron microscopy combining imaging at high magnification and electron diffraction and chemical data. This investigation is particularly important to distinguish four kinds of asbestiform minerals (antigorite, polygonal serpentine, carlosturanite, and balangeroite) from chrysotile since only the last one is regulated. The issue is much more complicated by the intergrowth of different fibrous species on the submicrometer scale.

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High tremolite asbestos content in urine related to dispersion from NOA rocks: a case study

10.5194/egusphere-egu2020-5730 ◽

2020 ◽

Author(s):

Elena Belluso ◽

Silvana Capella

Keyword(s):

Environmental Exposure ◽

Urine Analysis ◽

Western Alps ◽

Toxic Substances ◽

Department Of Health ◽

Naturally Occurring ◽

Professional Exposure ◽

Need To Evaluate ◽

Asbestiform Minerals ◽

Nw Italy

The naturally occurring asbestos (NOA) and naturally occurring of asbestiform minerals non asbestos classified (NONA) in North Western Italian Alps is known since many years and described in a few papers (e.g., Belluso et al., 1995; ARPA Piemonte, 2008). Whereas the noxiousness due to professional exposure to asbestos is well known, there are few information dealing with natural environmental exposure as that occurring to general population living closeness to NOA (and NONA) in outcropped rocks.The investigation of inorganic fibres content in urine may understand if people respired them in the latest period (from several days to some months: e.g., ATSDR, 2001).In this study we present a case of a very high and abnormal content of tremolite asbestos detected in urine of a young girl during a survey of several toxic contaminants respired from young students in a Turin province school (NW Italy).The absence of asbestos revealed by further investigation carried out in urine sample of girl&#8217;s parents and in other samples from the girl, showed that the high asbestos content previously detected was due to an exposure occurrence limited in time and related only to the girl.The investigation carried out on the lifestyle of the girl in the year preceding the urine analysis allowed to suppose that the detected high content of tremolite asbestos might be due to a specific environmental exposure. Indeed, the girl spent a holiday period away from her habitual home, where there were excavation works in NOA rocks spotty containing important amount of tremolite asbestos. Therefore, the asbestos detected in the urine is probably connected to those dispersed from NOA rocks.This finding focuses on the need to evaluate the risk of asbestos air dispersion from NOA rocks before carrying out excavation works.&#160;ARPA PIEMONTE (2008) Amianto naturale in Piemonte. Agenzia Regionale per la Protezione Ambientale del Piemonte, ARPA Piemonte, Ed. L&#8217;Artistica Savigliano (CN), IATSDR, Agency for Toxic substances and Disease Registry (2001). U.S., Department of Health and Human Services, Public Health Service. Atlanta, GA, USABELLUSO E, COMPAGNONI R, FERRARIS G. (1995) Occurrence of asbestiform minerals in the serpentinites of the Piemonte Zone, Western Alps. In: Giornata di studio in ricordo del Prof. Stefano Zucchetti, Politecnico di Torino, 57-64. Ed. Politecnico di Torino, I

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Automatic measurement of SAED patterns from asbestos minerals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100106296 ◽

1988 ◽

Vol 46 ◽

pp. 846-847

Author(s):

J. C. Russ ◽

T. Taguchi ◽

P. M. Peters ◽

E. Chatfield ◽

J. C. Russ ◽

...

Keyword(s):

Diffraction Pattern ◽

High Precision ◽

Diffraction Data ◽

Automatic Measurement ◽

Automatic Method ◽

Important Method ◽

X Ray ◽

Integrated Intensity ◽

Asbestiform Minerals ◽

True Center

Conventional SAD patterns as obtained in the TEM present difficulties for identification of materials such as asbestiform minerals, although diffraction data is considered to be an important method for making this purpose. The preferred orientation of the fibers and the spotty patterns that are obtained do not readily lend themselves to measurement of the integrated intensity values for each d-spacing, and even the d-spacings may be hard to determine precisely because the true center location for the broken rings requires estimation. We have implemented an automatic method for diffraction pattern measurement to overcome these problems. It automatically locates the center of patterns with high precision, measures the radius of each ring of spots in the pattern, and integrates the density of spots in that ring. The resulting spectrum of intensity vs. radius is then used just as a conventional X-ray diffractometer scan would be, to locate peaks and produce a list of d,I values suitable for search/match comparison to known or expected phases.

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Characterization of defects in tabular silver halide grains

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100178367 ◽

1990 ◽

Vol 48 (4) ◽

pp. 1046-1047

Author(s):

C. Goessens ◽

D. Schryvers ◽

J. Van Landuyt ◽

A. Verbeeck ◽

R. De Keyzer

Keyword(s):

Radiation Damage ◽

Silver Halide ◽

Chemical Characteristics ◽

X Ray ◽

Free Region ◽

Central Defect ◽

Crystallographic Defects ◽

Physical And Chemical ◽

Two Sides

Silver halide grains (AgX, X=Cl,Br,I) are commonly recognized as important entities in photographic applications. Depending on the preparation specifications one can grow cubic, octahedral, tabular a.o. morphologies, each with its own physical and chemical characteristics. In the present study crystallographic defects introduced by the mixing of 5-20% iodide in a growing AgBr tabular grain are investigated. X-ray diffractometry reveals the existence of a homogeneous Ag(Br1-xIx) region, expected to be formed around the AgBr kernel. In fig. 1 a two-beam BF image, taken at T≈100 K to diminish radiation damage, of a triangular tabular grain is presented, clearly showing defect contrast fringes along four of the six directions; the remaining two sides show similar contrast under relevant diffraction conditions. The width of the central defect free region corresponds with the pure AgBr kernel grown before the mixing with I. The thickness of a given grain lies between 0.15 and 0.3 μm: as indicated in fig. 2 triangular (resp. hexagonal) grains exhibit an uneven (resp. even) number of twin interfaces (i.e., between + and - twin variants) parallel with the (111) surfaces. The thickness of the grains and the existence of the twin variants was confirmed from CTEM images of perpendicular cuts.

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