Respiratory symptoms, lung function tests and airway responsiveness among crop farmers

Abstract

Objective: To evaluate the frequency of respiratory symptoms, lung function test abnormalities and non specific bronchial hyperresponsiveness (BHR) among crop farmers. Methods: A cross sectional study was performed including 50 males (mean age=45.4±10.7) employed as crop farmers (duration of exposure 21.6±9.7) and 50 male office workers as a control group (mean age=44.1±9.8) matched for age, smoking habits and socioeconomic status. Evaluation of examined subjects included completion of a questionnaire on respiratory symptoms in the last 12 months (cough, phlegm, dyspnea, wheezing, chest tightness, and nasal symptoms), spirometry and histamine challenge (PC20±8 mg/mL). Results: Crop farmers had a significantly higher prevalence of cough (29.4%), phlegm (16.7%), wheezing (11.9%), and nasal symptoms (10.2%) than the control group (p<0.05). All spirometric parameters (FVC, FEV1, FEV1/FVC%, MEF75, MEF50, and MEF25) were lower in crop farmers compared to the controls, but statistical significance was confirmed only for MEF25, MEF50, and MEF25-75 (p=0.02, p=0.01, and p=0.003; respectively). The prevalence of non specific BHR, defined by histamine PC20 less than 8 mg/mL, was higher in exposed crop farmers but statistical significance was yet not reached (21.7% vs. 12.2%). Conclusion: The study results suggest that occupational exposure among crop farmers is associated with a higher prevalence of respiratory and nasal symptoms, lung function impairment, as well as higher prevalence of non specific airway responsiveness.