Chrysotile asbestos is the main cause of pleural mesothelioma

Abstract

In contrast to amphibole forms of asbestos, chrysotile asbestos is often claimed to be only a minor cause of malignant pleural mesothelioma, a highly fatal cancer of the lining of the thoracic cavity. In this article we examine the evidence from animal and human studies that relates to this issue. Reported data do not support widely quoted views regarding the relative inertness of chrysotile fibers in mesothelioma causation. In fact, examination of all pertinent studies makes it clear that chrysotile asbestos is similar in potency to amphibole asbestos. Since asbestos is the major cause of mesothelioma, and chrysotile constitutes 95% of all asbestos use world wide, it can be concluded that chrysotile asbestos is the main cause of pleural mesothelioma in humans. © 1996 Wiley‐Liss, Inc.

Explaining differences in incidence rates of pleural mesothelioma between Sweden and the Netherlands

“…16,17 In Sweden and in The Netherlands the large majority of the import was chrysotile, but unfortunately there is no information about differences in the proportion of amphiboles in the total import of asbestos fibres. Amosite has been used primarily for spray insulation and crocidolite was used in the shipyard industry and asbestos cement industry.…”

Asbestos-Related Research: First Objectivity then Conclusions

“…Moreover, the accelerated clearance of chrysotile from the lung can be partly caused by a disintegration of chrysotile (but not amphibole) fibers into thin fibrils, which are more difficult to identify. The total number of fibrils would increase due to fiber splitting [47,49,50], possibly together with the carcinogenic effect, as the split fibrils can move to the pleura [45,47,48]. Asbestos fibers have been identified in the pleura by autopsy, chrysotile being the predominant asbestos form found in pleural plaques [51] and pleural/mesothelial tissues in general [46,52].…”

“…In certain animal experiments, the amphiboles and chrysotile were shown to be nearly equally carcinogenic for the induction of both Mt [50,58,60,61] and lung cancer [62,63]. Chrysotile was found to be even more carcinogenic than amphiboles in [60], where it was pointed out: "There was no evidence of either less carcinogenicity or less asbestosis in the groups exposed to chrysotile than those exposed to the amphiboles" [60].…”

Mineralogy and Malignant Mesothelioma: The South African Experience

“…The role of chrysotile in the causation of mesothelioma has been debated for decades (Churg, 1988;Huncharek, 1994;Smith and Wright, 1996;Stayner et al, 1996;Egilman et al, 2003;McDonald, 2010). One view is that the amphiboles (crocidolite, amosite and tremolite) explain almost all cases of mesothelioma and that "chrysotile mesothelioma" is induced by contaminating tremolite (McDonald, 2010).…”

“…One view is that the amphiboles (crocidolite, amosite and tremolite) explain almost all cases of mesothelioma and that "chrysotile mesothelioma" is induced by contaminating tremolite (McDonald, 2010). A contrasting opinion is that chrysotile is the main cause of mesothelioma (Smith and Wright, 1996). The South African experience of mesothelioma and chrysotile is of interest in this debate because the country mined, milled, transported and used large quantities of the fibre.…”