Morbidity of pulmonary tuberculosis among silicotic and nonsilicotic foundry workers in Denmark.

Increased tuberculosis risk associated with silicosis is well described. The present study defines the incidence of pulmonary tuberculosis among 5424 nonsilicotic and 155 silicotic male foundry workers observed between 1967 and 1986. For the 18-year follow-up period, the following groups had statistically significant increased standard incidence rates (SIR) for pulmonary tuberculosis: silicotics, SIR = 1000 (95% CI = 272 to 2561, P less than .01); nonsilicotics employed at least 25 years, SIR = 353 (95% CI = 130 to 768, P less than .01); and for the entire cohort, SIR = 201 (95% CI = 125 to 397, P = .01). These results suggest that silica exposure may cause an increased pulmonary tuberculosis risk among nonsilicotic foundry workers.