Background: A cross-sectional study was performed to determine the prevalence of respiratory symptoms in farmers and to assess occupational risk factors for respiratory symptoms in this population.
Method: A questionnaire on respiratory symptoms and occupation was mailed to a sample of 1,191 farmers with descriptive analysis of the symptoms and multivariate analysis through logistic modeling to assess the different risk factors.
Results: 1,164 workers answered the questionnaire (response index 98.2%) and 808 subjects were finally included in the study after discarding non exposed workers. The highest prevalences of asthma symptoms (39.2%) and symptoms of nasal allergy (31.6%) were found in poultry workers (p < 0.001, chi square). Sheep workers showed the highest prevalences of chronic phlegm (38.5%), work-related symptoms (53.9%) and symptoms of organic dust toxic syndrome (35.9%) (p < 0.005, chi square). At multivariate analysis, adjusting for age, gender, smoking and other occupational exposures, poultry work was a risk factor for asthma symptoms (OR 2.1; IC 95% 1.2-3.8) and symptoms of nasal allergy (OR 2.3, IC 95% 1.3-4.2), and dairy farming a risk factor for chronic phlegm (OR 1.8, IC 95% 1.1-2.9). Agriculture was not associated with respiratory symptoms.
Conclusion: In our study risk factors for respiratory symptoms in Spanish farmers were poultry and dairy farming.