Alterations in the laryngeal mucosa after exposure to asbestos.

The laryngeal mucosa of 195 workers in an asbestos cement factory (Salonit Anhovo, Yugoslavia) and in a control group was examined. The factory manufactures asbestos cement products containing about 13% of asbestos (8% amosite, 12% crocidolite, and 80% chrysotile) of different provenance. Alterations in the laryngeal mucosa were more frequent in the factory workers than in the control group. The changes, mostly consistent with chronic laryngitis, were closely related to the degree of workplace pollution and less so to the duration of employment Ten workers exhibiting the most severe clinical changes underwent biopsy, the results of which showed histomorphological changes characteristic of hyperplastic chronic laryngitis. Four tissue specimens were examined also by scanning electron microscopy and in three of them asbestos fibres were found on the epithelial surface. No case of laryngeal carcinoma was identified. On the basis of our results it is thought that asbestos related changes of the larynx should receive more attention and that the use of the term "laryngeal asbestosis" is justified. The clinical picture is non-specific but in view of their frequency such changes should be considered a consequence of exposure to asbestos.