Identification of iron compounds in chrysotile from the Balangero mine (Turin, Italy) by micro‐Raman spectroscopy

Abstract

Chrysotile, one of the six regulated asbestos minerals, is classified as carcinogenic to humans by the International Agency for Research on Cancer. The Balangero mine (Turin, Italy) was the largest asbestos mine in Europe, providing extraction of chrysotile fibers until 1990. Chrysotile from Balangero is currently of great interest in fibers toxicity studies focused on the understanding of the mechanisms that induce lung malignancies. One of the crucial factors in the biochemical reactions is the presence of Fe at the fibers surface. Surface reactivity is responsible for the generation of reactive oxygen species, which play an important role in asbestos cyto‐genotoxicity. Moreover, the dissolution of Fe‐bearing phases in the acidic environment of the lysosomes might be considered as possible release of hazardous Fe ions in the lungs. Here, chrysotile from Balangero was characterized by micro‐Raman spectroscopy and scanning electron microscope‐energy dispersive system (SEM‐EDS) analysis to identify the Fe‐bearing impurities associated with asbestos fibers. Micrometric crystals were recognized as Fe oxides, carbonates, and sulfides. Uncommonly reported phases in asbestos minerals were also identified, mainly as mackinawite (Fe(II)S), in different forms. The nature of the Fe compounds containing both Fe(II) and Fe(III) species was verified by micro‐Raman spectroscopy combined with SEM‐EDS analysis.

Waterborne asbestos: Good practices for surface waters analyses

“…This could derive from a partial deposition of large bundles during the water motion process or to adhesion of fibres on tank walls, possibly induced by electrostatic forces. Nevertheless, the powder dispersed in water to prepare the analytical sample could contain traces of mineral species other than chrysotile ( Fornasini et al, 2022 ) that would not be counted during the analysis, thus not contributing to the final mass calculation. Finally, a miscalculation due to the fact that many fibres lie partially outside of the images acquired (see counting criteria, paragraph 2.3) on which measurements are performed could also influence the final concentration value.…”

“…The chrysotile standard is a powder originating from the Balangero former mine, located next to Turin, Italy (45°17′32″N 7°31′01″E) (e.g. Fornasini et al, 2022 ), provided by RSA Srl 1 , the public company in charge of the remediation and environmental development of the former asbestos mine site of Balangero and Corio municipalities.…”

Advanced procedures in Raman forensic, natural, and cultural heritage studies: Mobile set‐up, optics, and data treatment—State of the art and perspectives

“…Several fragments of “pietra ollare” (soapstone) artifacts, dating back to the Medieval period, were analyzed by Fornasini et al 80 with both laboratory and mobile Raman instrumentations together with complementary techniques. Mobile Raman measurements assured a quick and effective evaluation of the samples' composition thus constituting a preliminary identification that could be obtained directly in situ.…”

Microstructure, Chemistry and Mineralogy Approach for the Diagnostics of Metallic Finds of the Tomba della Biga (Adria, Italy)

“…The center of sample 8 is characterized by light spots than the rest of the sample. Spectrum 1 shows goethite (Fe +3 O(OH)) [48], spectrum 2 lepidocrocite [49], while spectrum 3 corresponded to ilmenite (Figure 15c).…”