title: Effect of respirators equipped with particle or particle-and-gas filters during exposure in a pig confinement building.
abstract: OBJECTIVE
  This study compared the protective effect of two respiratory protection devices during exposure in a pig confinement building.
  
  
  METHODS
  Thirty-six healthy persons were exposed for 3 hours in the building, 12 without any protection, 12 with a particle-filter mask, and 12 with a mask filtering both particles and gases. Symptoms, body temperature, nasal lavage fluid, exhaled nitric oxide, and bronchial responsiveness to methacholine were assessed before and after the exposure. Pre- and postexposure urine and blood samples were collected.
  
  
  RESULTS
  After the exposure, the participants with respirators reported fewer symptoms than those without. Wearing a mask also reduced the inflammatory response assessed with nasal lavage (cell concentration, interleukins 6 and 8) and peripheral blood (cell number). Lung function was significantly impaired only in the unprotected group; postexposure vital capacity and forced expiratory volume in 1 second showed a decrease of 3-4% from the preexposure levels (P=0.006 and P=0.002, respectively). Bronchial responsiveness (P<0.01) and body temperature (P<0.001) increased similarly in the three groups. Bronchial responsiveness to methacholine increased 2.7, 2.4, and 2.1 doubling concentration steps for those unprotected, those using a particle-filter mask, and those using a mask with particle and gas filters, respectively. The prostaglandin D2 metabolite, 9a, 11b-PGF2 increased significantly (P=0.003) only in those unprotected.
  
  
  CONCLUSIONS
  Wearing a respirator in a pig confinement building reduces the inflammatory reaction but does not influence the increase in bronchial responsiveness, with no difference between the use of a particle-filter mask or a mask with a particle-gas filter combination.
authors: Lung and Allergy Research, National Institute of Environmental Medicine, Karolinska institutet, PO Box 287, S-17177 Stockholm, Sweden. Britt-Marie.Sundblad@imm.ki.se
authors: Britt-Marie
authors: BM
authors: Sundblad
authors: Karin
authors: K
authors: Sahlander
authors: Alexandra
authors: A
authors: Ek
authors: Maria
authors: M
authors: Kumlin
authors: Marianne
authors: M
authors: Olsson
authors: Kjell
authors: K
authors: Larsson
authors: Lena
authors: L
authors: Palmberg