title: Occupational exposure and severe pulmonary fibrosis.
abstract: BACKGROUND
  External agents, especially metal and wood dust, are believed to be risk factors for development of idiopathic pulmonary fibrosis (IPF). The aim of this case-control study was to investigate which occupational exposure types are associated with development of severe pulmonary fibrosis (PF), and especially IPF.
  
  
  METHODS
  An extensive postal questionnaire including 30 specific items regarding occupational exposure was completed by 181 patients with severe PF and respiratory failure reported to the Swedish Oxygen Register, among whom 140 were judged as having IPF. The questionnaire was also completed by 757 control subjects. We stratified data for age, sex and smoking and calculated odds ratios (ORs).
  
  
  RESULTS
  We found increased risk for IPF in men with exposure to birch dust (OR 2.7, 95% confidence interval (95% CI) 1.30-5.65) and hardwood dust (OR 2.7, 95% CI 1.14-6.52). Men also had slightly increased ORs associated with birds. We did not find any increased risk in association with metal dust exposure.
  
  
  CONCLUSIONS
  Exposure for birch and hardwood dust may contribute to the risk for IPF in men.
authors.affiliation: Department of Medicine, Skellefteå Hospital, SE-931 86 Skellefteå, Sweden. torbjorn.gustafson@vll.se
authors.forename: Torbjörn
authors.initials: T
authors.lastname: Gustafson
authors.forename: Anna
authors.initials: A
authors.lastname: Dahlman-Höglund
authors.forename: Kenneth
authors.initials: K
authors.lastname: Nilsson
authors.forename: Kerstin
authors.initials: K
authors.lastname: Ström
authors.forename: Göran
authors.initials: G
authors.lastname: Tornling
authors.forename: Kjell
authors.initials: K
authors.lastname: Torén
mesh_terms: D016022:Case-Control Studies; D004391:Dust / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D008670:Metals / Q000009:adverse effects*; D009784:Occupational Diseases / Q000453:epidemiology / Q000209:etiology*; D016273:Occupational Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D011658:Pulmonary Fibrosis / Q000453:epidemiology / Q000209:etiology*; D012307:Risk Factors; D012737:Sex Factors; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors; D014934:Wood / Q000009:adverse effects*
chemical_list: D004391:Dust; D008670:Metals