Observations on the Carcinogenidty of Asbestos Fibers

Abstract

This paper summarizes animal experiments and in vitro data carried out to study the oncogenic effects of asbestos fibers on mesothelial cells. An interpretation of the results is made in light of current statements on the carcinogenicity of asbestos fibers. Experimental results appear to show that the carcinogenicity of mineral fibers is a complex, multiparametric phenomenon. Chromosomal mutations and possibly oxygen derivatives are involved in the genesis of the fiber-induced neoplastic process and may be the result of the intrinsic fiber properties, size, and physicochemistry. The role of fiber solubility is discussed; it is suggested that additional experiments are necessary for a better understanding of the importance of solubility in the concept of biopersistence.

Synchrotron soft X-ray imaging and fluorescence microscopy reveal novel features of asbestos body morphology and composition in human lung tissues

“…The presence of transition metals in the fibres and/or their ability to absorb them is the first mechanism suggested for explaining the toxic and carcinogenic effects of asbestos. The presence of surface redox-active iron, which can be present in both ferrous (Fe 2+ ) and ferric (Fe 3+ ) forms, is supposed to be greatly responsible for the genotoxic and cytotoxic effects of amphibole asbestos fibres [5-10] by generating oxygen reactive species.…”

“…Among the commercially used asbestos fibres, the iron-rich crocidolite and amosite asbestos (containing 20-30% iron by weight), are considered the most carcinogenic [10-12] and are the ones most often found in lung tissues as ferruginous bodies with rare naked fibres. The presence of iron in the fibres seems to be also a key factor for the formation of the asbestos bodies via deposition of iron containing proteins (as ferritin).…”

Potential Toxicity of Nonregulated Asbestiform Minerals: Balangeroite From the Western Alps. Part 1: Identification and Characterization

“…However, a large number of experimental investigations, both in vitro and in vivo, indicate that three major factors may be responsible for asbestos toxicity (Kane et al, 1996;Vallyathan et al, 1998;Fubini & Otero-Aréan, 1999): 1. The fibrous nature, which favors translocation to pleura, frustrated phagocytosis by the immune system cells, and interaction with the mitotic spindle (Hesterberg & Barrett, 1985;Ault et al, 1995;Jaurand, 1991). 2.…”

Pathogenesis of malignant pleural mesothelioma and the role of environmental and genetic factors

“…However, he does admit that a threshold for chrysotile most likely exists though it has not yet been adequately detected by epidemiological research (Yarborough 2007). Although Yarborough's conclusions mainly support the Amphibole Hypothesis, they do not Jaurand (1991) did not Wnd this correlation. The role of the diVerent Wber types and the quantity of exposure necessary to cause MPM are still controversial.…”

“…The role of the diVerent Wber types and the quantity of exposure necessary to cause MPM are still controversial. The data are complicated by the variability in study designs and deWnitions as well as by the role of other risk factors such as genetics, industrial hygiene, and concomitant smoking (Jaurand 1991;Huuskonen et al 1995;Marchevsky et al 2006;Neuberger and Kundi 1990). However, the general consensus holds that longer Wbers and amphibole Wbers have more carcinogenic potential than their shorter and chrysotile counterparts in regards to MPM.…”