Exposure to brake dust and malignant mesothelioma: a study of 10 cases with mineral fiber analyses.

Published

Journal Article

OBJECTIVES: A large number of workers in the USA are exposed to chrysotile asbestos through brake repair, yet only a few cases of malignant mesothelioma (MM) have been described in this population. Epidemiologic and industrial hygiene studies have failed to demonstrate an increased risk of MM in brake workers. We present our experience of MM in individuals whose only known asbestos exposure was to brake dust and correlate these findings with lung asbestos fiber burdens. METHODS: Consultation files of one of the authors were reviewed for cases of MM in which brake dust was the only known asbestos exposure. Lung fiber analyses were performed using scanning electron microscopy (SEM) in all cases for which formalin-fixed or paraffin-embedded lung tissue was available. RESULTS: Ten cases of MM in brake dust-exposed individuals were males aged 51-73 yr. Nine cases arose in the pleura and one in the peritoneum. Although the median lung asbestos body count (19 AB/g) is at our upper limit of normal (range 0-20 AB/g), half of the cases had levels within our normal range. In every case with elevated asbestos fiber levels by SEM, excess commercial amphibole fibers were also detected. Elevated levels of chrysotile and non-commercial amphibole fibers were detected only in cases that also had increased commercial amphibole fibers. CONCLUSIONS: Brake dust contains exceedingly low levels of respirable chrysotile, much of which consists of short fibers subject to rapid pulmonary clearance. Elevated lung levels of commercial amphiboles in some brake workers suggest that unrecognized exposure to these fibers plays a critical role in the development of MM.

Full Text

Duke Authors

Cited Authors

  • Butnor, KJ; Sporn, TA; Roggli, VL

Published Date

  • June 2003

Published In

Volume / Issue

  • 47 / 4

Start / End Page

  • 325 - 330

PubMed ID

  • 12765873

Pubmed Central ID

  • 12765873

International Standard Serial Number (ISSN)

  • 0003-4878

Digital Object Identifier (DOI)

  • 10.1093/annhyg/meg048

Language

  • eng

Conference Location

  • England