LUNG-FUNCTION AND CHRONIC RESPIRATORY SYMPTOMS OF PIG FARMERS - FOCUSON EXPOSURE TO ENDOTOXINS AND AMMONIA AND USE OF DISINFECTANTS

Objectives-The prevalence of chronic respiratory symptoms among pig fa rmers is known to be high, but the aetiology of these symptoms is not yet unravelled. Long term average exposure to dust was evaluated, endo toxins and ammonia and use of disinfectants were compared with chronic respiratory symptoms and depressed base line lung function. Methods-A cross sectional study was performed among 194 Dutch pig farmers, of w hom 100 had not and 94 had chronic respiratory symptoms. Exposure-resp onse relations were evaluated with multiple logistic and linear regres sion analysis. Estimates of long term average exposure were based on t wo personal exposure measurements, taken on one day in summer and one day in winter. Information on use of disinfectants and disinfection pr ocedures was assessed by a walk through survey and interview by teleph one. Results-Exposure to dust, endotoxins, and ammonia were not relate d to chronic respiratory symptoms. Duration of the disinfection proced ure and pressure used Agricultural at disinfection were strongly and p ositively related to chronic respiratory symptoms. A significant inver se association between base line lung function and endotoxin exposure was found only among asymptomatic farmers. Ammonia exposure and durati on of the disinfection procedure were significantly associated with ba se line lung function in the entire population. Conclusion-Results sug gest that use of disinfectants is an important aetiological factor in chronic respiratory health effects of pig farmers. This factor has not been studied before. Results also suggest an aetiological role for ex posure to endotoxins and ammonia in development of chronic respiratory health effects, but longitudinal studies with detailed exposure asses sment strategies are required to assess their roles.