The prevalence of respiratory disease in a Midwest Hispanic (mostly Mexican) migrant farm worker population was investigated. Chronic respiratory symptoms (cough, wheezing, sputum production) in adult workers (n = 354) were elevated (8.5%, 6.2%, 6.5%, respectively) and were accompanied by physiologic abnormalities as determined by pulmonary function testing. Over 15% of the adult cohort exhibited a FEV1/FVC < 75, and over 14% had FEF25-75 values which were less than 60% of predicted. The observed airflow obstruction of both large and small airways was not explained by cigarette usage (43%) in the adult cohort (current/past smokers). Tuberculin skin tests (TST) were positive (> or = 10 mm) in 55/195 men and 35/123 women for a total prevalence of 28.3%. No case of active tuberculosis (TB) was identified by either chest X-ray (CXR) or sputum cultures (in selected cases). In contrast to adult farm workers, who were predominantly born in Mexico (70%), only 36% of adolescent workers (age 11-18 years, n = 107) were born in Mexico with only 7.5% exhibiting TST positivity. Airflow obstruction of large airways (5.8%) and small airways (12.9%) were also less common in adolescents than adults. In summary, these studies document respiratory dysfunction in Hispanic migrant farm workers in Indiana and highlight the need to closely monitor the respiratory health of this high-risk population.