The Tucson Study of Chronic Obstructive Lung Diseases was longitudinal in design. By 1986, nine surveys had been completed on 70 percent of the same population surveyed at baseline in 1972. Data collected in the surveys included basic standardized questionnaires and maximum expiratory flow volume (MEFV) curves using the same pneumotachograph equipment. Additional questionnaires were included on smoking, medical and occupational history, socio-economic characteristics, and height and weight measurements. Blood was sampled for studies of alpha-1-antitrypsin level. Several surveys included allergy skin testing, blood pressure, and anthropometric measurements. Studies of the 504 out-migrants continued since 1982. Twelve surveys were planned to insure a follow-up of at least 15 years on all adults.