Objective: To study whether dairy workers in California have lower baseline and greater cross-shift decrements in lung function than control employees.
Methods: A cross-sectional study of 210 dairy and 47 control workers who completed questionnaires and spirometry before and after the work shift.
Results: Dairy work was associated with mean baseline differences of −0.132 L (P = 0.07) and −0.131 L (P = 0.13) in forced expiratory volume in 1 second and forced vital capacity, respectively, compared with control employees, adjusting for age, height, smoking status, and days back at work since last day off. Dairy work was associated with a mean cross-shift difference of −65.2 mL (P = 0.02) and −103.1 mL (P < 0.01) in forced expiratory volume in 1 second and forced vital capacity, respectively, adjusting for smoking status and work-shift time.
Conclusions: Dairy work in California was associated with mild acute airway obstruction. The unclear long-term effect of dairy work in California merits further investigation.