Asbestos and cancer of the larynx: is there a relationship?

A head and neck examination was conducted on 322 personnel in a plant that manufactures brake linings and disks where asbestos is a major component. The personnel were categorized according to occupational risk, duration of employment, and smoking and alcohol habits. Thirty-nine percent had abnormalities, the most common being laryngitis (15%), deviated nasal septum (13%), and neck mass (5.3%). Six members required a biopsy, but no cancer was discovered. Of 47 personnel with laryngitis, 46 were smokers (P less than .01). In regard to asbestos exposure, 20% of the high-risk group had laryngitis, compared to 11% in the low-risk group (P less than .05). The data were compared to a previously prepared longitudinal study of plant personnel (2057 individuals and 37,361.5 person years), where three cases of laryngeal cancer had been observed (0.77 expected). As these cases involved smokers with limited asbestos exposure, neither the longitudinal or cross-sectional data could support asbestos as an etiologic factor for laryngeal cancer, but it may act as an irritant.