title: A prospective study of decline in lung function in relation to welding emissions.
abstract: BACKGROUND
  Numerous cross-sectional studies have reported reduced lung function among welders but limitations of exposure assessment and design preclude causal inference. The aim of this study was to investigate if long-term exposure to welding fume particulates accelerates the age-related decline in lung function.
  
  
  METHODS
  Lung function was measured by spirometry in 1987 and 2004 among 68 steel welders and 32 non-welding production workers. The decline in forced expiratory volume (FEV1) was analysed in relation to cumulated exposure to fume particulates among welders during the follow-up period.
  
  
  RESULTS
  Among smokers the decline in FEV1 through follow-up period was in average 150 ml larger among welders than non-welders while the difference was negligible among non-smokers. The results did not reach statistical significance and within welders the decline in lung function was not related to the cumulated welding particulate exposure during follow-up period
  
  
  CONCLUSIONS
  Long-term exposure to welding emissions may accelerate the age-related decline of lung function but at exposure levels in the range of 1.5 to 6.5 mg/m3 the average annual excess loss of FEV1 is unlikely to exceed 25 ml in smokers and 10 ml in non-smokers.
authors.affiliation: Department of Occupational Medicine, Arhus Hospital, Arhus University Hospital, Arhus, Denmark. jpbon@as.aaa.dk.
authors.forename: Sigve W
authors.initials: SW
authors.lastname: Christensen
authors.forename: Jens Peter
authors.initials: JP
authors.lastname: Bonde
authors.forename: Oyvind
authors.initials: O
authors.lastname: Omland