Could Sputum Eosinophilia Act as a Predictive Test for Diagnosis of High Risk Bakery Workers to Asthma?

Abstract

Background: Occupational flour inhalation has been a culprit in the start of several pulmonary diseases such as asthma. We examined the relationship between occupational wheat flour inhalation in bakery and supermarket employees with pulmonary functions, respiratory symptoms, and sputum eosinophilia to determine hyper-responsiveness in a cross-sectional study in Iran. Methods: 122 subjects from traditional bakeries and 137 subjects from supermarket employees were enrolled in the study. Flour exposure concentrations, respiratory signs, sputum analysis, and respiratory volumes and capacities were measured based on the standard methods. Results: Respirable concentration of flour in the bakery workers was two- to four-fold of ACGIH’s threshold limit value in which bread-bakers with 2.2 mg/m 3 experienced maximum exposures. The supermarket employees were not exposed to flour dust. The respiratory volumes in both bakery and supermarket employees were in the normal range. However, the median of voluminal percentage in bakery workers except Forced Vital Capacity (FVC) decreased ( p < 0.001). The mean respiratory volume of bread-bakers was reduced compared to supermarket employees ( p < 0.05). In addition, we observed increased respiratory symptoms in the bakery workers, again more prevalent in the bread-bakers. There was a significant correlation between flour exposure concentration and sputum eosinophilia in which the percentage of eosinophilia in the bread-bakers was more than other bakery and supermarket employees. Although there were reductions in the respiratory volumes, the results indicated no obstructive spirometric pattern. Conclusions: Sputum eosinophilia might be a suitable screening method to detect airway hyper-responsiveness in workers exposed to known asthmogens.