Respiratory symptoms and pulmonary impairment in male and female subjects with pottery workers' silicosis.

Respiratory symptoms, smoking habit, lung function and radiological category of silicosis were assessed in 276 present and former pottery workers who were receiving industrial disablement benefit for silicosis. There were 140 females and 136 males. The proportion with conglomerate disease (massive fibrosis) was similar in both sexes. The FEV1 declined with increasing X-ray category of silicosis irrespective of smoking habit and was most marked in subjects with symptomatic chronic bronchitis. In females who had never smoked the average decline of FEV1 in those with simple silicosis was 18 ml year-1 and for those with conglomerate disease 38 ml year-1. Symptomatic chronic bronchitis was common and only partly related to smoking, occurring in 69% of 101 nonsmoking female silicotic patients. No significant changes were observed in vital capacity, lung volume or transfer factor for carbon monoxide.