Upper and lower respiratory signs and symptoms in workers occupationally exposed to flour dust

A group of 142 bakers was studied in order to investigate the relationship between higher/lower respiratory signs/symptoms and inflammation biomarkers and occupational exposure to flour dust. A complete upper and lower respiratory tract evaluation was performed. Seven percent of bakers complained of lower respiratory symptoms, while 22% of them complained of upper respiratory symptoms. Fifty five percent of the bakers were allergic, and 37.1% showed sensitization to occupational allergens. Abnormal spirometries were found in 15% of bakers, while fractional exhaled nitric oxide (FeNO) was above the normal reference in 24.5% of them. Moreover, 23.8% of bakers were found to be hyposmic. Population mean peak nasal inspiratory flow (PNIF) was in the normal range even if almost all the workers suffered from neutrophilic rhinitis at nasal cytology with the number of nasal neutrophils increasing with the increase of the duration of exposure to flour dust (p = 0.03). PNIF and FEV1 (forced expiratory volume in the 1st second) showed a positive correlation (p = 0.03; r = 0.19). The Tiffeneau index decreased with the increase of dust (p = 0.017). A similar result was obtained once we divided our population into smokers and non-smokers (p = 0.021). Long-term exposure to bakery dusts can lead to a status of minimal nasal inflammation and allergy.