title: Exhaled breath condensate pH and FeNO as biomarkers of acute and chronic exposure to hazards at swine farms.
abstract: OBJECTIVE
  The noninvasive biomarkers of respiratory impairment were assessed in 15 swine confinement (SC) workers and 9 respiratory healthy, nonsmoking volunteers (HV).
  
  
  METHODS
  Spirometry, fraction of exhaled nitric oxide (FeNO), and exhaled breath condensate (EBC) pH were assessed in SC workers after one working shift and one working week and in HV after 5-hour exposure in SC.
  
  
  RESULTS
  Half of the respiratory symptoms (in 8 of 15 SC workers) were work-related. Basal FeNO values were 7.5 ppb higher in the SC workers compared with HV. In the SC workers, EBC pH increased for 0.17 at the end of a working week (P < 0.001). In HV, 5-hour exposure in SC induced 8% drop in forced expiratory flow at 25% of the pulmonary volume (FEF25) (P = 0.008), EBC pH drop for 0.10 units (P = 0.003), and FeNO drop by 1.8 ppb (P = 0.047).
  
  
  CONCLUSIONS
  EBC pH was suggested as a biomarker of acute airway acidification in HV, whereas the SC workers showed signs of the "healthy worker effect."
authors.affiliation: From the Institute for Medical Research and Occupational Health (Drs Ljubičić, Varnai, and Macan) and The Faculty of Veterinary Medicine, University of Zagreb (Prof Vučemilo and Dr Matković); and Swine Farm "Dubravica" (Dr Milić), Croatia.
authors.forename: Anita
authors.initials: A
authors.lastname: Ljubičić
authors.forename: Veda Marija
authors.initials: VM
authors.lastname: Varnai
authors.forename: Marija
authors.initials: M
authors.lastname: Vučemilo
authors.forename: Kristina
authors.initials: K
authors.lastname: Matković
authors.forename: Dinka
authors.initials: D
authors.lastname: Milić
authors.forename: Jelena
authors.initials: J
authors.lastname: Macan
mesh_terms: D000136:Acid-Base Equilibrium / Q000502:physiology*; D000328:Adult; D000822:Animal Husbandry; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D001944:Breath Tests; D045853:Exhalation; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000032:analysis*; D016273:Occupational Exposure / Q000032:analysis*; D012143:Respiratory Physiological Phenomena; D013147:Spirometry; D013552:Swine; D055815:Young Adult
chemical_list: D015415:Biomarkers; D009569:Nitric Oxide