Respirable dust exposure and respiratory health in male Taiwanese steelworkers

The objective of this cross-sectional study was to investigate the prevalence and determinants of respiratory symptoms and lung function and their association with occupational dust exposure in Taiwanese steelworkers. The study was conducted on an integrated-steel company in Taiwan from March 1989 to February 1990. After excluding workers in the coke ovens and ex-smokers, we performed physical examinations on 1,339 male workers in the iron making and steel making factories. Subjects were interviewed regarding respiratory symptoms using a Chinese version of the American Thoracic Society respiratory questionnaire and were examined with respect to their lung function using spirometry. Objective dust exposure was measured using personal air sampling with 277 valid samples. Prevalences of cough frequently, chronic cough, phlegm frequently, chronic phlegm, wheezing occasionally, and breathlessness were 11.4%, 9.3%, 14.6%, 11.9%, 2.6%, and 6.5%, respectively. Duration of employment, smoking, subjective dustiness, and past respiratory illnesses can predict these respiratory symptoms. Average respirable dust exposure significantly decreased the forced vital capacity (FVC) and forced expiratory volume in one second (FEVI.0) in smoking workers. In the non-smokers, an effect of respirable dust exposure on FEVl.0/FVC was shown. Since the main ingredients of dust in such a steelworks usually contained mixtures of oxides and silicates other than silica dust, respirable dust exposure in steelworks might impair lung function, especially among smokers.