Lung volume reference values for blue collar workers not exposed to occupational respiratory hazards

Epidemiologic research into occupationally related lung disease often requires the comparison of a study group with an external nonexposed comparison group. In order to develop such an external comparison group, blue collar workers, who had no obvious adverse occupational pulmonary exposure, performed simple spirometry, were administered a standard questionnaire, and had standard posterior-anterior and lateral chest radiographs taken. Prediction equations were established for three indices of lung volume, namely total lung capacity, residual volume, and their ratio, for various combinations of race, sex, and smoking groups. Asymptomatic non-smokers with normal radiograph results were then extracted from the overall group, and separate prediction equations were established. The relationship between age and total lung capacity is discussed.