title: Bronchial hyperresponsiveness and exposure in pig farmers.
abstract: OBJECTIVE
  To study the effect of exposure on bronchial responsiveness in pig farmers.
  
  
  METHODS
  A group of 196 pig farmers were tested for lung function and bronchial responsiveness to histamine in the summer of 1992. To achieve sufficient contrast in respiratory morbidity and exposure, 96 of the farmers were selected because they had chronic respiratory symptoms and the remaining 100 because they were free from any respiratory symptoms. Personal exposure to dust, endotoxins and ammonia was measured during 1 working day in the summer of 1991 and 1 day in the winter of 1992. Data on farm characteristics were gathered in the same period.
  
  
  RESULTS
  After adjusting for age and smoking behaviour, mild bronchial responsiveness, defined as PC10 < or = 16 mg/ml, was associated with the use of quaternary ammonium compounds as disinfectant [prevalence odds ratio (POR) 6.7, 95% confidence interval (CI) 1.4-32.8], use of wood-shavings as bedding (POR 13.3, CI 1.3-136.7), use of automated dry feeding (POR 2.8, CI 1.0-7.8), use of pellets as feeding material (POR 4.8, CI 1.1-21.1) and location of air exhaust via pit or roof in the confinement units (POR 2.7, CI 1.2-6.3). The association with the use of disinfectants other than quaternary ammonium compounds was not significant (POR 2.4, CI 0.7-8.4). No associations between bronchial responsiveness and measured exposure to dust, endotoxins or ammonia were discernible.
  
  
  CONCLUSIONS
  Protective measures, designed to prevent airway disease in confinement farming, should be based on information about the operational and other characteristics of farms that are related to high exposure and health effects. Specifically, the use of quaternary ammonium compounds as disinfectant, the use of wood-shavings as bedding and the use of automated dry feeding should be discouraged.
authors.affiliation: Department of General Practice and Social Medicine, University of Nijmegen, The Netherlands. P.Vogelzang@hsv.kun.nl
authors.forename: P F
authors.initials: PF
authors.lastname: Vogelzang
authors.forename: J W
authors.initials: JW
authors.lastname: van der Gulden
authors.forename: L
authors.initials: L
authors.lastname: Preller
authors.forename: M J
authors.initials: MJ
authors.lastname: Tielen
authors.forename: C P
authors.initials: CP
authors.lastname: van Schayck
authors.forename: H
authors.initials: H
authors.lastname: Folgering
mesh_terms: D000328:Adult; D000382:Agricultural Workers' Diseases / Q000209:etiology / Q000503:physiopathology*; D000818:Animals; D016535:Bronchial Hyperreactivity / Q000503:physiopathology*; D004202:Disinfectants / Q000009:adverse effects; D004391:Dust / Q000009:adverse effects; D004731:Endotoxins / Q000009:adverse effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D000644:Quaternary Ammonium Compounds / Q000009:adverse effects; D013552:Swine
chemical_list: D004202:Disinfectants; D004391:Dust; D004731:Endotoxins; D000644:Quaternary Ammonium Compounds