Association between bronchial hyper-reactivity and exposure to silicon carbide.

A clinical study of 191 workers in the silicon carbide production industry was carried out in order to determine the prevalence of respiratory symptoms (wheezing, dyspnoea and breathlessness after exercise). Such symptoms occurred in 50 (26.1%) subjects, of whom 24 accepted testing for bronchial reactivity. Of these 24, 19 (79.2%) were positive. These findings suggest that exposure to SiC may be associated with bronchial hyper-reactivity. Positive results were more frequent in women than in men, while differences between smokers and non-smokers were insignificant, a phenomenon that has often been noted in persons exposed to massive risk.