Respiratory morbidity in rubber workers: I. Prevalence of respiratory symptoms and disease in curing workers

One hundred twenty-one men who were exposed to tire-curing fumes responded to respiratory symptom questionnaires. Results were compared with questionnaires of 189 nonexposed workers who were employed by the same three tire manufacturing plants. The curing workers had a higher prevalence of chronic bronchitis than the controls. Of the curing workers with more than ten years of experience to fumes, 25% met the criteria for the epidemiological diagnosis of chronic obstructive pulmonary disease. Increased respiratory morbidity in the curing workers was related to both intensity and length of exposure to fumes. Because cigarette smoking and other variables cannot explain the difference between the curing and control groups, we attribute the greater prevalence of respiratory morbidity to exposure to curing fumes. These findings warrant further longitudinal studies and reduction of exposure, especially for workers on the manual automobile tire presses, which is the high-exposure group.