WORK-RELATED DISTAL AIRWAY-OBSTRUCTION IN AN AGRICULTURAL POPULATION

Objective-To assess the prevalence of distal airway obstruction and it s risk factors in agricultural areas. Methods-A cross sectional study of respiratory symptoms and lung function was performed among French f armers and their spouses (1122 subjects) who came for preventive medic ine examinations. They answered a respiratory questionnaire and perfor med pulmonary function tests on a portable spirometer. Diagnoses of ch ronic bronchitis were made on the basis of reported chronic respirator y symptoms. Airway obstruction was determined from predicted values. O dds ratio (OR) and linear regression coefficients were calculated afte r stratification by smoking and history of cardiac and other respirato ry diseases. Results-Of respiratory symptoms prevalence of chronic cou gh was 8.47%, and chronic bronchitis 7.66%. Prevalence of distal airwa y obstruction was 11.4%, and overall airflow obstruction 3.2%. Smokers were 20.2% men, and 5.7% women. Linear regressions showed high associ ation between pack-years in smokers or exsmokers and forced expiratory volume in one second/forced vital capacity (FEV(1)/VC) and forced exp iratory flow between 25% and 75% of vital capacity (FEF(25-75)). in no n-smokers without any history of cardiac or respiratory diseases, age and the size of farms had the highest correlations with these variable s. OR for distal airway obstruction was 2.1 in subjects >50 years old v the younger ones and 3.02 in the smaller farms v the larger ones. Co nclusion-After stratification by smoking and history of cardiac and re spiratory diseases, distal airway obstruction is present in agricultur al areas. The age, and the size of farm are the highest respiratory ri sk factors in non-smokers.