Objectives: The aim of this study was to determine the concentrations of respirable flour dusts and gliadin as well as gliadin-specific serum antibodies in exposed workers of Hamadan wheat flour mill factories.
Methods: Blood samples from 95 exposed workers and 80 air samples from flour packing, husk packing, flour production and wheat unloading areas were collected. Respirable flour dust density was measured by a gravimetric method, and dust gliadin concentration as well as serum antibodies were determined by enzyme-linked immunosorbent assays.
Results: The Time-weighted average (TWA) flour dust density was higher in all factories (1.56-4.68 mg/m(3)) compared with the threshold limit value (0.5 mg/m(3)) of ACGIH and showed a positive correlation with the gliadin concentration (p<0.05). Additionally, the respirable dust and gliadin concentrations were significantly higher at flour packing workstations compare with the other work areas. Moreover, the mean serum gliadin-specific IgA and IgG and total IgE antibodies were remarkably higher in exposed mill workers compared with the controls (p<0.05).
Conclusion: We clearly demonstrated that workers in Hamadan flour mills are in exposed to a hazardous level of respirable flour dust, receiving the highest level of dust and gliadin in flour packing areas. Furthermore, dust-exposed workers showed upper levels of serum antibodies indicating exposure to higher amounts of allergens than controls.