Respiratory symptoms and pulmonary function among Chinese rice-granary workers.

The authors conducted a cross-sectional study of 474 rice-granary workers and 235 non-granary worker controls in a rural area near Shanghai, the People's Republic of China. Responses to a respiratory-symptom questionnaire and pre- and post-shift spirometry were obtained for all subjects. Area sampling was performed for total and vertically elutriated (</= 15 micrometer) dust levels. Total dust levels were high, ranging from 6.6 mg/m(3) to 59.8 mg/m(3), with vertical elutriated dust concentrations ranging from 2.0 to 10. 4 mg/m(3). The granary workers reported significantly more respiratory symptoms, including chronic cough, sputum production, chronic bronchitis, grain fever (ODTS), and nasal and skin irritation. Grain dust and tobacco smoking were more than additive for the prevalence of chronic cough and chronic bronchitis. After adjusting for confounders, the granary workers had lower mean FEV&inf1;/FVC values both pre- and post-shift, indicating an association between chronic grain-dust exposure and chronic airway obstruction. The results suggest that exposure to rice dust can induce pulmonary responses similar to those observed with exposures to other types of grains.