Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5846163 | Toxicology and Applied Pharmacology | 2015 | 15 Pages |
Abstract
This study was designed to provide an understanding of the biokinetics and potential toxicology in the lung and pleura following inhalation of brake dust following short term exposure in rats. The deposition, translocation and pathological response of brake-dust derived from brake pads manufactured with chrysotile were evaluated in comparison to the amphibole, crocidolite asbestos. Rats were exposed by inhalation 6 h/day for 5 days to either brake-dust obtained by sanding of brake-drums manufactured with chrysotile, a mixture of chrysotile and the brake-dust or crocidolite asbestos. The chrysotile fibers were relatively biosoluble whereas the crocidolite asbestos fibers persisted through the life-time of the animal. This was reflected in the lung and the pleura where no significant pathological response was observed at any time point in the brake dust or chrysotile/brake dust exposure groups through 365 days post exposure. In contrast, crocidolite asbestos produced a rapid inflammatory response in the lung parenchyma and the pleura, inducing a significant increase in fibrotic response in both of these compartments. Crocidolite fibers were observed embedded in the diaphragm with activated mesothelial cells immediately after cessation of exposure. While no chrysotile fibers were found in the mediastinal lymph nodes, crocidolite fibers of up to 35 μm were observed. These results provide support that brake-dust derived from chrysotile containing brake drums would not initiate a pathological response in the lung or the pleural cavity following short term inhalation.
Keywords
GSDBrake dustGMLMMMFVDITransforming growth factor (TGF)-βTGF-ßPDGFCTGFbFGFGMDMMADgeometric standard deviationLungWorld Health OrganizationConnective tissue growth factorplatelet-derived growth factorbasic fibroblast growth factorMass median aerodynamic diametergeometric mean diameterSEMscanning electron microscopeConfocal microscopyPleuraChrysotileWHO
Related Topics
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Health, Toxicology and Mutagenesis
Authors
D.M. Bernstein, R.A. Rogers, R. Sepulveda, P. Kunzendorf, B. Bellmann, H. Ernst, O. Creutzenberg, J.I. Phillips,