Respiratory illness in the construction trades. I. The significance of asbestos-associated pleural disease among sheet metal workers.

To assess the rate of roentgenographic and lung function abnormalities in asbestos-exposed construction workers, the authors studied 314 white male members of a local sheet metal workers union. Health outcomes were assessed by questionnaire, simple spirometry, and chest roentgenography; data were collected and interpreted following guidelines of the American Thoracic Society and the International Labor Office. Analyses of union records showed the tested population to be representative of all those eligible for testing. Pleural abnormalities were common, increasing to a prevalence of approximately 70% in workers with more than 30 years employment. Roentgenographic evidence of pleural disease was significantly correlated with decreased forced vital capacity (p = 0.027) after controlling for the potential confounding effects of age, height, cigarette consumption history, and employment duration. In contrast, forced expiratory volume in 1 s showed a stronger association with amount smoked (p = 0.022) than with pleural abnormality (p = 0.316). Logistic regression analyses showed that cigarettes act to increase the effect of asbestos in causing pleural disease among exposed workers. Cigarettes, in the absence of significant asbestos exposure, do not appear to cause pleural disease. The authors conclude that construction workers, such as those described herein, have a considerably increased rate of pleural disease, which has functional significance in view of the correlations noted with forced vital capacity measurements. Therefore, pleural disease in asbestos-exposed workers is not only an indicator of exposure but also an indicator of early impairment of pulmonary function.