A prospective study of decline in lung function in relation to welding emissions

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 (FEV(1)) was analysed in relation to cumulated exposure to fume particulates among welders during the follow-up period. RESULTS: Among smokers the decline in FEV(1 )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 CONCLUSION: 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/m(3 )the average annual excess loss of FEV(1 )is unlikely to exceed 25 ml in smokers and 10 ml in non-smokers.