Organic aerosols and the development of allergic disorders

The aim of this study was to investigate skin reactivity to organic dust extracts and total serum IgE and their relation to the prevalence of respiratory symptoms and ventilatory capacity in workers occupationally exposed to organic aerosols. It included workers employed in processing coffee, tea, dried fruits, spices, animal food, soy, hemp, cotton, swine farmers, and control groups of workers non-exposed to organic dust. All underwent a skin prick test (SPT) with water extracts of organic dust 1:10 w/v, Dermatophagoides pteronyssinus, mixed moulds, bacteria, histamin solution (1 mg/ml) and buffer solution. SPT was considered positive if the diameter of the observed wheal was 3 mm greater than that of buffer solution. The total IgE was measured by the PRIST method (Pharmacia Diagnostics AB, Upsala) and the values > 125 kU/L were considered increased. Data on respiratory symptoms were collected by standardized questionnaire. Ventilatory capacity was measured by recording MEFV curve. Airborne industrial dust were measured as total and respirable fraction. The exposed workers had a greater prevalence of positive SPT to organic dust extracts, except in soy processing. Increased IgE was found in workers processing coffee, tea, hemp, cotton and animal food, compared to non-exposed workers (P<0.05). Workers with positive SPT had a significantly higher total IgE. As there was no correlation between acute and chronic changes in ventilatory function, positive SPT, and level of total IgE, our findings could not predict objective respiratory impairment.