Among the different natural and industrial materials, asbestos are still retained to be significantly dangerous for the human health and in the majority of countries their uses and manipulations are ruled out by laws (Plumlee et al., 2006). The term asbestos is generally used to describe minerals that either occur as long silky fibres or can be easily split so as to become such. The asbestos minerals are currently sub classed into two main groups: (i) serpentines (e.g. chrysotile) and (ii) amphiboles (e.g., tremolite, riebeckite). It is now retained that fibrous amphiboles are significantly more dangerous than fibrous serpentines (McDonald and McDonald, 1997; Plumlee et al., 2006). Therefore it is extremely important to characterise the fibrous amphiboles (natural and industrial) occurring in the environment as airborne dust, particularly with respect to their chemistry. However despite of a relatively large amount of medical and biochemical studies devoted to the toxicological effects of asbestos (especially on amphiboles), the mineralogical characterisation of the fibrous minerals was normally little constrained. Several parameters can in fact be supposed responsible for their biological hazard, and these include the Fe content of the fibres, the absolute dimensions and aspect-ratio of the crystallites, the electrical surface potential, the solubility as a function of pH, and the hydrophobicity vs. hydrophilicity (van Oss et al., 1999); all these properties are notably dependent on their chemistry, and thus their knowledge is of capital importance for any investigations dealing on amphibole asbestos. A rather rapid, complete and accurate crystal-chemical investigations of (fibrous) amphiboles can be carried out by the combination of SEM, XRPD and FTIR OH-stretching data. We checked this analytical protocol on a set of asbestos amphiboles from the Libby quarry, Montana (USA). These samples were previously studied and characterized by EPMA, Mössbauer and single crystal XRD. Our crystal-chemical results well matched with those reported in literature. This definitively indicates that the spectroscopic (FTIR) methods offer a very fast tool for a proper characterization of fibrous amphiboles in environmental monitoring. References: McDonald, J.C., McDonald, A.D. (1997). Annals of Occupational Hygiene, 41(6), 699-705. Plumlee G.S., Morman S.A., Ziegler T.H. (2006). Reviews in Mineralogy and Geochemistry, vol. 64:5-57. van Oss, C.J., Naim, J.O., Costanza, P.M., Giese, R.F. Jr., Wu, W., Sorling, A.F. (1999). Clays and Clay Minerals, 47, 697-707.
Iezzi, G., DELLA VENTURA, G., Di Gioacchino, M., Bellatreccia, F., Verna, N., Gunter, M.e., et al. (2007). Amphibole asbestos from Libby (Montana, USA): mineralogical data for toxicological applications, 263-263.
Amphibole asbestos from Libby (Montana, USA): mineralogical data for toxicological applications
DELLA VENTURA, Giancarlo;BELLATRECCIA, FABIO;
2007-01-01
Abstract
Among the different natural and industrial materials, asbestos are still retained to be significantly dangerous for the human health and in the majority of countries their uses and manipulations are ruled out by laws (Plumlee et al., 2006). The term asbestos is generally used to describe minerals that either occur as long silky fibres or can be easily split so as to become such. The asbestos minerals are currently sub classed into two main groups: (i) serpentines (e.g. chrysotile) and (ii) amphiboles (e.g., tremolite, riebeckite). It is now retained that fibrous amphiboles are significantly more dangerous than fibrous serpentines (McDonald and McDonald, 1997; Plumlee et al., 2006). Therefore it is extremely important to characterise the fibrous amphiboles (natural and industrial) occurring in the environment as airborne dust, particularly with respect to their chemistry. However despite of a relatively large amount of medical and biochemical studies devoted to the toxicological effects of asbestos (especially on amphiboles), the mineralogical characterisation of the fibrous minerals was normally little constrained. Several parameters can in fact be supposed responsible for their biological hazard, and these include the Fe content of the fibres, the absolute dimensions and aspect-ratio of the crystallites, the electrical surface potential, the solubility as a function of pH, and the hydrophobicity vs. hydrophilicity (van Oss et al., 1999); all these properties are notably dependent on their chemistry, and thus their knowledge is of capital importance for any investigations dealing on amphibole asbestos. A rather rapid, complete and accurate crystal-chemical investigations of (fibrous) amphiboles can be carried out by the combination of SEM, XRPD and FTIR OH-stretching data. We checked this analytical protocol on a set of asbestos amphiboles from the Libby quarry, Montana (USA). These samples were previously studied and characterized by EPMA, Mössbauer and single crystal XRD. Our crystal-chemical results well matched with those reported in literature. This definitively indicates that the spectroscopic (FTIR) methods offer a very fast tool for a proper characterization of fibrous amphiboles in environmental monitoring. References: McDonald, J.C., McDonald, A.D. (1997). Annals of Occupational Hygiene, 41(6), 699-705. Plumlee G.S., Morman S.A., Ziegler T.H. (2006). Reviews in Mineralogy and Geochemistry, vol. 64:5-57. van Oss, C.J., Naim, J.O., Costanza, P.M., Giese, R.F. Jr., Wu, W., Sorling, A.F. (1999). Clays and Clay Minerals, 47, 697-707.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
