Pulmonary function and respiratory symptoms in potash workers.

Over 94% of the workers in each of four Saskatchewan potash mines participated in a respiratory health surveillance program that included a questionnaire and pulmonary function tests. Compared with a nonexposed control group, potash workers had higher prevalences of cough, dyspnea, and chronic bronchitis but better pulmonary function. Prevalences of symptoms and pulmonary function abnormalities were similar among workers at the four mines tested and at the various job locations.