Naturally occurring asbestos in an alpine ophiolitic complex (northern Corsica, France)

Lahondère, Didier; Cagnard, Florence; Duron, Jéromine

doi:10.1007/s12665-019-8548-x

Cited by 3 publications

(1 citation statement)

References 44 publications

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“…In the natural environment, a large set of metamorphic rocks may contain asbestos fibers, such as meta-ophiolitic rocks of basic or ultrabasic compositions (meta-gabbros, meta-basalts, serpentinites) (e.g. [4][5][6]) and hydrothermally altered dolerites ( [7]), more rarely in talc deposits ( [8]), metamorphosed dolostones and iron formations ( [9]) and subalkaline plutonic rocks ( [10]). Asbestos is listed as a Category 1 human carcinogen, because inhalation of asbestos fibers causes respiratory diseases, in particular asbestosis, lung cancers, and malignant mesothelioma (e.g.…”

Section: Introductionmentioning

confidence: 99%

Coupling SEM-EDS and confocal Raman-in-SEM imaging: A new method for identification and 3D morphology of asbestos-like fibers in a mineral matrix

Lahondère¹,

Schmidt²,

Duron³

et al. 2019

Journal of Hazardous Materials

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Asbestos consists in natural minerals crystallized in a specific habit and possessing in particular properties. In the case of Naturally Occurring Asbestos, usual methods applied to the identification of mineral fibers and the determination of their possible asbestiform nature seems not efficient, especially in the case of mineral fibers included in mineral matrix.We present a new in-situ method based on the use of confocal Raman-in-SEM imaging implemented in a Scanning Electron Microscope as an efficient method for in-situ mineralogy. The limitation of conventional methods is discussed. We applied 2D-Raman imaging to the identification of sub-micrometric fibers included in different mineral matrix. We were able to identify actinolite fibers down to 400 nm in diameter, included in feldspar, quartz and/or calcite matrix. HighlightsNew methods are requested for characterizing asbestos fibers in a mineral matrix SEM-Raman imaging is efficient for characterizing mineral fibers in-situ Confocal Raman imaging makes 3D analysis possible 3D analysis provides information on the aspect ratio and volume fraction of asbestos Fibers thinner than 400nm can be identified by confocal Raman in SEM ( = 532 nm) Keywords in-situ asbestos diagnosis; Raman-in-SEM imaging; naturally occurring asbestos; 3D analysis; fibrous amphiboles;

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Section: Introductionmentioning

confidence: 99%

Coupling SEM-EDS and confocal Raman-in-SEM imaging: A new method for identification and 3D morphology of asbestos-like fibers in a mineral matrix

Lahondère¹,

Schmidt²,

Duron³

et al. 2019

Journal of Hazardous Materials

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Naturally Occurring Asbestos in France: Geological Mapping, Mineral Characterization, and Technical Developments

Cagnard

Lahondère

2020

Environmental and Engineering Geoscience

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In France, asbestos was banned by national decree (no. 96-1133) in 1996. The regulatory texts and standards adopted to implement this ban are concerned primarily with asbestos-containing manufactured products and are difficult to apply to asbestos-bearing natural materials (i.e., rocks and soils). Considering problems related to asbestos-bearing natural materials, the French Ministry of Ecology, Sustainable Development, and Energy has mandated the French Geological Survey to map locations where asbestos-bearing rocks are found. Mapping was prioritized to geological domains where naturally occurring asbestos (NOA) was predictable (e.g., the Western Alps and Corsica). These studies integrated field expertise, sampling, and laboratory analysis data to characterize the potential of geological units to contain NOA. Additionally, studies were conducted on geological formations exploited to produce aggregates. These studies were focused on quarries excavating massive, basic or ultrabasic rocks likely to contain NOA and quarries mining alluvium likely to contain asbestos-bearing rock pebbles. These studies highlight the difficulty of establishing robust analytical procedures for natural materials. The distinction between cleavage fragments (resulting from the fragmentation of non-asbestos particles) and proper asbestos fibers is particularly problematic for laboratories. Thus, a recent study by the National Agency for Health Safety, Food, Environment, and Work recommends applying the asbestos regulation to elongated mineral particles (length/depth > 3:1, length > 5 μm, depth < 3 μm) with chemical composition corresponding to one of the five regulated amphibole species regardless of their mode of crystallization (asbestiform or non-asbestiform). The upcoming regulatory changes are part of a decree published in 2017, including the prior identification of asbestos in natural soils or rocks likely to be impacted by ground-disturbing construction activities. Specific protocols will be defined for sampling, analysis, and characterization of natural materials that may contain asbestos.

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Asbestos Hazard in Serpentinite Rocks: Influence of Mineralogical and Structural Characteristics on Fiber Potential Release

Marzini,

Iannini,

Giorgetti

et al. 2024

Geosciences

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Naturally occurring asbestos (NOA) represents a matter of social and environmental concern due to its potential release in the atmosphere during rock excavation and grinding in quarry and road tunnel activities. In most cases, NOA occurs in serpentinites, i.e., rocks deriving from low-grade metamorphic hydration of mantle peridotites. The potential release of asbestos fibers from serpentinite outcrops depends on several features, such as serpentinization degree, rock deformation, weathering, and abundance of fibrous veins. In this study, we selected a set of serpentinite samples from a representative outcrop in Tuscany (Italy), and we analyzed them by Optical, Scanning, and Transmission Electron Microscopies. The samples were treated by grinding tests following the Italian guidelines Decrees 14/5/96 and 152/2006 for the determination of the Release Index (RI), i.e., the fiber amount released through controlled crushing tests. The fine-grained powder released during the tests was analyzed by quantitative Fourier transform infrared spectroscopy (FTIR) to determine the variety and the amount of released fibers and to assess the potential hazard of the different serpentinite samples. Results indicate that the amount of released fibers is mostly related to serpentinite deformation, with the highest RI values for cataclastic and foliated samples, typically characterized by widespread occurrence of fibrous veins. Conversely, massive pseudomorphic serpentinite revealed a very low RI, even if their actual chrysotile content is up to 20–25%. Based on our original findings from the RI results, a preliminary investigation of the outcrop at the mesoscale would be of primary importance to obtain a reliable hazard assessment of NOA sites, allowing the primary distinction among the different serpentinites lithotypes and the effective fiber release.

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Naturally occurring asbestos in an alpine ophiolitic complex (northern Corsica, France)

Cited by 3 publications

References 44 publications

Coupling SEM-EDS and confocal Raman-in-SEM imaging: A new method for identification and 3D morphology of asbestos-like fibers in a mineral matrix

Coupling SEM-EDS and confocal Raman-in-SEM imaging: A new method for identification and 3D morphology of asbestos-like fibers in a mineral matrix

Naturally Occurring Asbestos in France: Geological Mapping, Mineral Characterization, and Technical Developments

Asbestos Hazard in Serpentinite Rocks: Influence of Mineralogical and Structural Characteristics on Fiber Potential Release

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