Lung function changes in coke oven workers during 12 years of follow up.

Aims: To investigate the effect of exposure to coke oven emissions on the lung function of coke oven workers. Methods: The study population, followed from 1978 and 1990, was 580 male workers with at least two sets of lung function measurements (FVC, FEV₁, FEV₁/FVC, and FEF_25-75%). An annual rate of change (time slope) for age and height adjusted lung function index was estimated for each subject. This "time slope" was then treated as the response variable in a weighted multiple regression analysis with selected predictors. Results: For all 580 subjects, each year of working in the "operation" group (the most exposed) was found to increase the FVC decline by around 0.7 ml/year (95% CI 0.1 to 1.3 ml/year). After the exclusion of 111 subjects without detailed work history, the above finding was confirmed and each year of exposure in "operation" was also found to increase the FEV₁ decline by around 0.8 ml/year (95% CI 0.1 to 1.4 ml/ year). Conclusions: These findings are consistent with the results of previous cross-sectional studies. Work duration in the most exposed position in the coke ovens was associated with increased annual decline for FVC and FEV₁. The estimated effect of one year of work exposure in "operation" is equivalent, in terms of the reduction in lung function, to an estimated 2.1 pack-years of smoking for FVC and 1.2 pack-years of smoking for FEV₁. [ABSTRACT FROM AUTHOR]