Am. J. Respir. Crit. Care Med.,
Volume 164, Number 3, August 2001, 499-503
Pseudoasbestos Bodies and Fibers in Bronchoalveolar
Lavage of Refractory Ceramic Fiber Users
PASCAL
DUMORTIER,
INGRID
BROUCKE,
and
PAUL
DE VUYST
Chest Department, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
Refractory ceramic fibers (RCF) are widely used to replace asbestos in applications requiring high heat resistance. Ferruginous bodies mimicking asbestos bodies (ABs) have been detected in the lungs of RCF production workers. This raises the question about their presence in other occupational groups and whether "typical ABs" still reflect past asbestos exposures in all settings. An AB
counting by phase-contrast light microscopy and a screening test
by analytical electron microscopy were systematically performed on all bronchoalveolar lavage fluids (BALF) submitted to our laboratory in 1992 through 1997 (n = 1,800). When RCF were detected in electron microscopy, the structures considered as "typical ABs" were marked under light microscopy and prepared for
further chemical and structural analysis. Pseudo-ABs on RCF were
detected in samples from nine subjects (0.5%). All of them had
worked either as foundry workers, steel workers, or welders. In
these subjects, alumino-silicate fibers compatible with RCF accounted for 42% of the core fibers analyzed, other nonasbestos fibers for 28%, and asbestos fibers for 30%. ABs thus remain a valid
marker of asbestos retention but attention must be paid to a possible occurrence of pseudo-asbestos bodies on RCF and other nonasbestos fibers in end-users of refractory fibers.
Keywords: asbestos; refractory ceramic fibers; biopersistence; bronchoalveolar lavage fluid; transmission electron microscopy
