Experimental Asbestosis

The Potential Contribution of Hexavalent Chromium to the Carcinogenicity of Chrysotile Asbestos

“…In previous studies, trace metals (including Cr) on chrysotile surfaces were postulated as potential contributors to the carcinogenicity of the fibers. ,− The results from our experiments combined with the efficient in vivo dissolution of Cr from intrapleurally administered chrysotile in rats , support this hypothesis. The Cr content of chrysotile is typically in the lower g kg –1 range (in Shijiazhuang chrysotile 1.3–1.4 g kg –1 , Table ), which is strongly enriched relative to the bulk Cr content of the amphibole asbestos minerals amosite and crocidolite .…”

“…Apart from Fe, first order transition metals in chrysotile include Cr, Ni, Mn, Co, and Zn. Particularly, the Cr and Ni bulk contents of chrysotile (both in the low g kg –1 range) are highly enriched, relative to the common amphibole asbestos minerals amosite and crocidolite. − In chrysotile, these trace metals substitute Mg, but they are also found in associated phase impurities in the raw chrysotile material. , The content of both Cr and Ni also increases during the industrial processing of crude fibers, e.g., during crushing and milling with equipment from steel alloys that contain these metals. , The concentrations of most trace metals can be larger in impurities from associated minerals and alloys than in chrysotile itself . In vivo, chromium and cobalt readily dissolved from intrapleurally administered chrysotile in rats, and both metals leached at much higher rates than Fe. , …”

“…Even though the contribution of Cr to the carcinogenicity of chrysotile has been postulated before, ,− the fate and reactivity of chrysotile-associated Cr in the lungs and pleura are still poorly understood. A fast release of Cr from chrysotile administered intrapleurally was observed in rats, , which appears counterintuitive, as the solubility of Cr­(III) (as contained in chrysotile) at the physiologic pH of 7.4 is low. , Therefore, the leaching of Cr from chrysotile at this pH required investigation.…”

Association of asbestos and bronchogenic carcinoma in a population with low asbestos exposure

“…These are not counted by some investigators, 6. 7 Short asbestos fibers or fibrils with the typical morphological appearance of chrysotile (Figs. 3B and C) were identified in each of the cases of lung cancer with more than 50 bodies/g of tissue. Occasionally, long multifiber bundles, such as are shown in Figure 3C, were visible.…”

Ψευδαργυρος Και Μαγνησιον Εις Τον Καρκινον Του Παγκρεατος

“…Άργότερον oi Cralley et al (1967) παρουσίασαν στοιχεία ενοχοποιητικά άναφορικώς μέ τό νικέλιον, τό χρώμιον, τό μαγγάνιον κα'ι τον σίδηρον έπ'ι ανθρώπων. ΟΊ Gross et al (1967) (Bertrand και Bhattacherjee 1934, Todd et al 1934, Bertrand και Bhattacherjee 1935, ακολούθως δέ εις τον έπίμυν (Stirn et al 1935). 'Αρκετά ετη ένωρίτερον ό Maze (1914) είχεν ανακαλύψει ότι ό ψευδάργυρος ήτο απαραίτητος δια τήν άνάπτυξιν τοϋ φυτού Zea mays.…”