Modelling the Fenton reaction of amphibole asbestos
- 1G. Scansetti Interdepartmental Center for Studies on Asbestos and Other Toxic Particulates and Department of Chemistry, University of Torino, V. P. Giuria 7, I-10125, Torino, Italy
- 2Department of Medicine, Epidemiology, Occupational and Environmental Hygiene, National Institute for Insurance against Accidents at Work (INAIL), Roma, Italy
- 3Department of Earth Sciences, Sapienza University of Rome, Piazzale Aldo Moro, 5-I-00185 Roma, Italy
- 4Department of Chemical and Geological Sciences, INSTM Research, University of Cagliari, 09042 Monserrato, Cagliari, Italy
- 5Department of Biology, Ecology and Earth Sciences, University of Calabria, V. P. Bucci, I-87036, Arcavacata di Rende, CS, Italy
- 6ENEA - Casaccia Research Centre Via Anguillarese, 301, S. Maria Di Galeria, 00123 Roma, Italy
- 7The Italian Institute for Environmental Protection and Research (ISPRA), via Vitaliano Brancati 48, 00144 Roma, Italy
In this work a sample of UICC crocidolite and a sample of fibrous tremolite were leached up to 1 week both in a simplified Gamble’s solution at acidic pH and in a phosphate buffered medium at neutral pH, in presence of H2O2. Surface chemical modifications were monitored by XPS spectroscopy. Subsequently, the generation of HO• radicals following reaction of both pristine and leached fibres with H2O2 (Fenton reaction) was investigated by spin trapping/EPR spectroscopy, with the aim of better clarifying the relationships between possible surface alteration occurring in vivo and chemical reactivity of amphibole asbestos. Moreover, the generation of HO• radicals was monitored on thermally treated fibres after leaching in phosphate buffered medium at neutral pH and in presence of H2O2 to investigate how chemical reactivity may be modulated by Fe oxidation state.
Results showed that, for both amphibole asbestos, the surface alteration following incubation in the modified Gamble’s solution does not alter HO• radical generation. Interestingly, leaching in phosphate buffered solution in presence of H2O2 induced a progressive increase in HO• release for crocidolite fibres, whereas a strong reduction was observed for asbestos tremolite. This behaviour is likely due to the quicker alteration of the crocidolite surface due to the interaction with H2O2, as indicated by XPS analysis. In particular, the oxidation induced by H2O2 promotes the dissolution of the first atomic layer of the crocidolite structure and the following occurrence on its surface of new reactive Fe centres, particularly under the form of Fe(II), of which the bulk is richer than the oxidized surface. Accordingly, the heated samples showed a reduced, but not suppressed by thermal oxidation, chemical reactivity, with no significant evolution following incubation in phosphate buffered medium at neutral pH and in presence of H2O2.
How to cite: Tomatis, M., Turci, F., Petriglieri, J. R., Campopiano, A., Cannizzaro, A., Ballirano, P., Fantauzzi, M., Rossi, A., Bloise, A., Montereali, M. R., Nardi, E., and Pacella, A.: Modelling the Fenton reaction of amphibole asbestos, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4710, https://doi.org/10.5194/egusphere-egu22-4710, 2022.
