There is plenty of asbestos at the bottom. The case of magnesite raw material contaminated with asbestos fibres

Alessandro F Gualtieri; Daniele Malferrari; Dario Di Giuseppe; Valentina Scognamiglio; Orietta Sala; Magdalena Lassinantti Gualtieri; Danilo Bersani; Laura Fornasini; Enrico Mugnaioli

doi:10.1016/j.scitotenv.2023.166275

There is plenty of asbestos at the bottom. The case of magnesite raw material contaminated with asbestos fibres

Sci Total Environ. 2023 Nov 10:898:166275. doi: 10.1016/j.scitotenv.2023.166275. Epub 2023 Aug 13.

Authors

Alessandro F Gualtieri¹, Daniele Malferrari², Dario Di Giuseppe³, Valentina Scognamiglio³, Orietta Sala³, Magdalena Lassinantti Gualtieri⁴, Danilo Bersani⁵, Laura Fornasini⁵, Enrico Mugnaioli⁶

Affiliations

¹ Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Via G. Campi 103, 41125 Modena, Italy; Inter-Departmental Research and Innovation Centre on Construction and Environmental Services of the University of Modena and Reggio Emilia, Italy.
² Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Via G. Campi 103, 41125 Modena, Italy; Inter-Departmental Research and Innovation Centre on Construction and Environmental Services of the University of Modena and Reggio Emilia, Italy. Electronic address: daniele.malferrari@unimore.it.
³ Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Via G. Campi 103, 41125 Modena, Italy.
⁴ Department of Engineering "Enzo Ferrari", University of Modena and Reggio Emilia, Via Vivarelli 10, 41125 Modena, Italy.
⁵ Department of Mathematical, Physical and Computer Sciences, University of Parma, Parco Area delle Scienze 7/A, 43124 Parma, Italy.
⁶ Department of Earth Sciences, University of Pisa, Via Santa Maria 53, 56126 Pisa, Italy.

PMID: 37582451
DOI: 10.1016/j.scitotenv.2023.166275

Abstract

Although all six asbestos minerals (the layer silicate chrysotile and five chain silicate species actinolite asbestos, amosite, anthophyllite asbestos, crocidolite and tremolite asbestos) are classified as carcinogenic, chrysotile is still mined and used in many countries worldwide. Other countries, like Italy, impose zero tolerance for all asbestos species, but conflicting views repress the development of globally uniform treaties controlling international trade of asbestos-containing materials. Hence, countries with more severe legislations against the use of these hazardous materials lack of an international safety net against importation of non-compliant products. This research reports the first discovery of commercial magnesite raw materials contaminated with white asbestos (chrysotile). X-ray powder diffraction and thermogravimetric/thermodifferential measurements showed the presence of serpentine group minerals in both the semi-processed (powder) and quarried material. The univocal identification of chrysotile in the powders was confirmed by its peculiar Raman bands of the OH stretching vibrations between 3500 and 3800 cm^-1, with an intense peak at ∼3695 cm^-1 and a weak contribution at ∼3647 cm^-1. Transmission electron microscope showed that chrysotile forms fibres up to a few microns long and up to 80 nm thick with a nanotube structure characterized by inner channels as large as 30-40 nm. Fibres size analysis obtained by scanning electron microscopy indicates mean length and diameter of 5.95 and 0.109 μm with medians of 2.62 and 0.096 μm, respectively; some among the fibres analysed exhibit the so-called "Stanton size" (i.e., asbestos fibres longer than 8 μm and thinner than 0.25 μm that are strongly carcinogenic). Quantitative analysis showed a chrysotile content around 0.01 wt% not allowed by current regulations in Italy and many other countries. More generally, our findings demonstrate that without shared policies aimed at regulating asbestos circulation on the global market, "asbestos-free" national policies will inevitably fail.

Keywords: Asbestos; Chrysotile; Electron microscopy; Magnesite; REACH; Rotterdam Convention.