Iron topochemistry and surface reactivity of amphibole asbestos: relations with in vitro toxicity

Abstract

Chemical reactivity of asbestos tremolite from Italy and USA localities and Union Internationale Contre le Cancer (UICC) crocidolite was studied in relation to Fe content, oxidation state, and structural coordination. Direct correlation between amount of Fe(2+) at the exposed M(1) and M(2) sites of the amphibole structure and fiber chemical reactivity was established. The in vitro toxicity of the same samples was investigated on human alveolar A549 cell line. Relationship between crystal-chemical features and cell toxicity is not straightforward. UICC crocidolite has Fe content and chemical reactivity largely higher than that of tremolite samples, but all show comparable in vitro toxic potential. Results obtained evidenced that Fe topochemistry is not a primary factor for induced cell toxicity, though it accounts for asbestos chemical reactivity (and possibly genotoxicity).

Crystal chemical and structural modifications of erionite fibers leached with simulated lung fluids

“…Despite it has been reported as the most mobile among the EF cations throughout heating of erionite-K (Ballirano and Cametti 2012), there is no convincing evidence that Mg 2+ is released by the fibers to SLFs during leaching. Unfortunately such information would be of paramount importance to confirm/ rule out the occurrence of the effects on lipid packing, membrane permeability, as well as counteraction of Ca 2+ uptake attributed to Mg 2+ release from amphibole asbestos reported from in vitro experiments (Bergamini et al 2004;Pacella et al 2012).…”

Surface and Bulk Modifications of Fibrous Erionite in Mimicked Gamble’s Solution at Acidic pH

“…The observed trend further confirms that the ion exchange process is pronounced in the first 24 h of incubation. Notably, the ions released by erionite when immersed in MGS may trigger biological effects, because it was shown that Ca ions are able to induce opening of the permeability transition pore of the inner membrane leading to a possible cytotoxic effect due to the release of apoptotic factors normally localized in the mitochondrial intermembrane space, whereas Mg ions may have different effects on lipid packing and membrane permeability [69,70].…”

Chemo-physical properties of asbestos bodies in human lung tissues studied at the nano-scale by non-invasive, label free x-ray imaging and spectroscopic techniques

“…However, other works suggested that they might enhance the cytotoxic properties of asbestos, showing that no consensus has been yet reached on their pathogenetic role. In particular, in vitro and in vivo experiments (respectively, with cell cultures and animals), showed that ABs are able to induce the generation of free radicals (Ghio et al, 2008;Governa, M. Amati, 1999;Pacella et al, 2012), double strand breaks in the DNA (Lund et al, 1994), and that the iron contained in the coating is catalytically active (Fubini and Mollo, 1995;Governa, M. Amati, 1999;Hardy and Aust, 1995). Even if key mechanisms by which asbestos would start the chain of events leading to MM have been proposed (Andreozzi et al, 2017;Pacella et al, 2015Pacella et al, , 2010Yang et al, 2010Yang et al, , 2006, less attention was devoted to the role of the ABs.…”