Workers at six potash mines located close to each other in New Mexico were visited by medical and industrial hygiene teams in 1976. Demographic, anthropometric and spirometric information was collected, and data on chest symptoms, work and smoking history were elicited. Posterior-anterior and lateral chest radiographs were taken. About the same time a thorough assessment of the environment was made at each mine. The data were examined for possible relationships between health indices, dust exposure and measures reflecting exposure to diesel exhaust. No obvious links incriminating either dust or the diesel exhaust could be ascertained, though symptom prevalences were elevated compared with a non-dust exposed group.