Evaluation of the fate and pathological response in the lung and pleura of brake dust alone and in combination with added chrysotile compared to crocidolite asbestos following short-term inhalation exposure

Journal Article · Sun Feb 15 04:00:00 EST 2015 · Toxicology and Applied Pharmacology

DOI:https://doi.org/10.1016/J.TAAP.2014.12.012· OSTI ID:22465696

Sepulveda, R. ^[1]; Bellmann, B. ^[2]; Creutzenberg, O. ^[2]

---

1. Rogers Imaging, Needham, MA (United States)
2. Fraunhofer Institute for Toxicology and Experimental Medicine, Hannover (Germany)

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. - Highlights: • Evaluated brake dust w/wo added chrysotile in comparison to crocidolite asbestos. • Persistence, translocation, pathological response in the lung and pleural cavity. • Chrysotile cleared rapidly from the lung while the crocidolite asbestos persisted. • No significant pathology in lung or pleural cavity observed at any time point in the brake-dust groups. • Crocidolite quickly produced pathological response in the lung and pleural cavity.

• OSTI ID: 22465696
• Journal Information: Toxicology and Applied Pharmacology, Journal Name: Toxicology and Applied Pharmacology Journal Issue: 1 Vol. 283; ISSN TXAPA9; ISSN 0041-008X
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
AMPHIBOLE
ASBESTOS
COLLAGEN
COMPARATIVE EVALUATIONS
CONNECTIVE TISSUE
DUSTS
FIBERS
FIBROBLASTS
GROWTH FACTORS
INFLAMMATION
INHALATION
LUNGS
LYMPH NODES
PATHOGENS
PATHOLOGY
PLEURA
RATS
SAND
SCANNING ELECTRON MICROSCOPY