Respiratory morbidity induced by occupational inhalation exposure to high concentrations of wheat flour dust.

INTRODUCTION The main purpose of this study was to investigate the respiratory effects of exposure to high airborne concentrations of wheat flour dust. METHODS This cross-sectional study was carried out at a local wheat flour mill in Shiraz, southern Iran. Thirty-five male workers exposed to flour dust and 32 healthy male nonexposed employees were investigated. The prevalence of respiratory symptoms among them was evaluated and parameters of their pulmonary function were measured. Moreover, to assess the extent to which subjects were exposed to flour dust, airborne concentrations of its inhalable and respirable fractions were measured. RESULTS Airborne concentrations of dust exceeded current permissible level. The prevalence of regular cough, productive cough, wheezing, phlegm and dyspnea was significantly higher in exposed subjects than in nonexposed employees. Similarly, both acute and chronic significant (p < .05) decrements in most parameters of pulmonary function were noted. CONCLUSIONS Our findings provide corroborative evidence to further support the notion that exposure to flour dust is associated with a significant increase in the prevalence of respiratory symptoms as well as ventilator disorders of the lungs.