title: Acute respiratory effects and biomarkers of inflammation due to welding-derived nanoparticle aggregates.
abstract: OBJECTIVE
  Welders are exposed to airborne particles from the welding environment and often develop symptoms work-related from the airways. A large fraction of the particles from welding are in the nano-size range. In this study we investigate if the welders' airways are affected by exposure to particles derived from gas metal arc welding in mild steel in levels corresponding to a normal welding day.
  
  
  METHODS
  In an exposure chamber, 11 welders with and 10 welders without work-related symptoms from the lower airways and 11 non-welders without symptoms, were exposed to welding fumes (1 mg/m3) and to filtered air, respectively, in a double-blind manner. Symptoms from eyes and upper and lower airways and lung function were registered. Blood and nasal lavage (NL) were sampled before, immediately after and the morning after exposure for analysis of markers of oxidative stress. Exhaled breath condensate (EBC) for analysis of leukotriene B4 (LT-B4) was sampled before, during and immediately after exposure.
  
  
  RESULTS
  No adverse effects of welding exposure were found regarding symptoms and lung function. However, EBC LT-B4 decreased significantly in all participants after welding exposure compared to filtered air. NL IL-6 increased immediately after exposure in the two non-symptomatic groups and blood neutrophils tended to increase in the symptomatic welder group. The morning after, neutrophils and serum IL-8 had decreased in all three groups after welding exposure. Remarkably, the symptomatic welder group had a tenfold higher level of EBC LT-B4 compared to the two groups without symptoms.
  
  
  CONCLUSIONS
  Despite no clinical adverse effects at welding, changes in inflammatory markers may indicate subclinical effects even at exposure below the present Swedish threshold limit (8 h TWA respirable dust).
authors.affiliation: Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, 221 85, Lund, Sweden. katrin.dierschke@med.lu.se.
authors.forename: Katrin
authors.identifier: http://orcid.org/0000-0002-5769-5961
authors.initials: K
authors.lastname: Dierschke
authors.affiliation: Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, Lund, Sweden.
authors.forename: Christina
authors.initials: C
authors.lastname: Isaxon
authors.affiliation: Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, 221 85, Lund, Sweden.
authors.forename: Ulla B K
authors.initials: UBK
authors.lastname: Andersson
authors.affiliation: Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, 221 85, Lund, Sweden.
authors.forename: Eva
authors.initials: E
authors.lastname: Assarsson
authors.affiliation: Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, 221 85, Lund, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Axmon
authors.affiliation: Occupational and Environmental Medicine, Gothenburg University, Gothenburg, Sweden.
authors.forename: Leo
authors.initials: L
authors.lastname: Stockfelt
authors.affiliation: Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, Lund, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Gudmundsson
authors.affiliation: Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, 221 85, Lund, Sweden.
authors.forename: Bo A G
authors.initials: BAG
authors.lastname: Jönsson
authors.affiliation: Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, 221 85, Lund, Sweden.
authors.forename: Monica
authors.initials: M
authors.lastname: Kåredal
authors.affiliation: Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, Lund, Sweden.
authors.forename: Jakob
authors.initials: J
authors.lastname: Löndahl
authors.affiliation: Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, Lund, Sweden.
authors.forename: Joakim
authors.initials: J
authors.lastname: Pagels
authors.affiliation: Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, Lund, Sweden.
authors.forename: Aneta
authors.initials: A
authors.lastname: Wierzbicka
authors.affiliation: Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, Lund, Sweden.
authors.forename: Mats
authors.initials: M
authors.lastname: Bohgard
authors.affiliation: Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, 221 85, Lund, Sweden.
authors.forename: Jörn
authors.initials: J
authors.lastname: Nielsen
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers; D004311:Double-Blind Method; D004391:Dust; D006801:Humans; D015850:Interleukin-6 / Q000032:analysis; D007975:Leukotriene B4 / Q000009:adverse effects*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D053758:Nanoparticles / Q000009:adverse effects*; D055556:Nasal Lavage; D009504:Neutrophils; D016273:Occupational Exposure / Q000009:adverse effects*; D012129:Respiratory Function Tests; D011795:Surveys and Questionnaires; D013548:Sweden; D014896:Welding
chemical_list: D015415:Biomarkers; D004391:Dust; D015850:Interleukin-6; D007975:Leukotriene B4
keywords: Exhaled breath condensate; Interleukin 6 and 8; Leukotriene B4; Nasal lavage; Occupational exposure