Physical and Biochemical Properties of Airborne Flour Particles Involved in Occupational Asthma

• Published in: The Annals of occupational hygiene 2008-11, Vol.52 (8), p.727-737
• Main Authors: Laurière, Michel, Gorner, Peter, Bouchez-Mahiout, Isabelle, Wrobel, Richard, Breton, Christine, Fabriès, Jean-François, Choudat, Dominique
• Format: Article
• Language: English
• Subjects: Adult; Aerosols; Air Pollutants, Occupational - analysis; Asthma - etiology; Biological and medical sciences; cereal flours; Chemical and industrial products toxicology. Toxic occupational diseases; Chronic obstructive pulmonary disease, asthma; Environmental Monitoring - methods; Flour - adverse effects; Flour - analysis; flour dust; Food Industry; Humans; inhaled particles; Inorganic dusts (pneumoconiosises) and organic dusts (byssinosis etc.); Male; Medical sciences; Microscopy, Electron, Scanning; Non tumoral diseases; occupational asthma; Occupational Diseases - etiology; Occupational Medicine - methods; Otorhinolaryngology. Stomatology; Particle Size; Pneumology; rhinitis; Secale; Secale cereale; Toxicology; Triticum; Triticum aestivum; Upper respiratory tract, upper alimentary tract, paranasal sinuses, salivary glands: diseases, semeiology
• ISSN: 0003-4878; 1475-3162; 1475-3162
• DOI: 10.1093/annhyg/men061

Aerosol particles which deeply penetrate the human airways and which trigger baker's asthma manifestations are known to represent only a part of flour and of airborne particles found in bakeries. They were a major focus of this study. To this end, aerosols were produced from different wheat and rye flours, using an automatic generator designed for bronchial challenge. Particles were characterized for their size distribution, their ability to be deposited in the airways, their protein content, their histological composition and their reactivity with immunoglobulin E (IgE) present in sera from asthmatic bakers. Like dust particles collected in the bakery, the aerosols produced showed increased protein content but decreased IgE reactive protein content when compared to the corresponding bulk flours. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of these particles showed a predominance of endosperm gluten proteins. Under scanning electron microscopy, flour particles displayed various tissue fragments with entrapped large A-starch and small B- or C-starch granules, whereas aerosol particles appeared primarily as a mixture of the endosperm intracellular interstitial protein matrix and small B- or C-starch granules free or still associated. These observations showed that aerosols supposed to penetrate deeply the airways, mainly correspond to intracellular fragments of endosperm cells enriched in gluten proteins but with lower amount of allergens belonging to albumins or globulins.