Cumulative exposure to dust and gases as determinants of lung function decline in tunnel construction workers

Aims: To study the relation between lung function decrease and cumulative exposure to dust and gases in
tunnel construction workers.
Methods: A total of 651 male construction workers (drill and blast workers, tunnel concrete workers,
shotcreting operators, and tunnel boring machine workers) were followed up by spirometric measurements
in 1989–2002 for an average of six years. Outdoor concrete workers, foremen, and engineers served as
a low exposed referent population.
Results: The between worker component of variability was considerably reduced within the job groups
compared to the whole population, suggesting that the workers within job groups had similar exposure
levels. The annual decrease in FEV1 in low-exposed non-smoking workers was 21 ml and 24 ml in lowexposed ever smokers. The annual decrease in FEV1 in tunnel construction workers was 20–31 ml higher
than the low exposed workers depending on job group for both non-smokers and ever smokers. After
adjustment for age and observation time, cumulative exposure to nitrogen dioxide showed the strongest
association with a decrease in FEV1 in both non-smokers, and ever smokers.
Conclusion: Cumulative exposure to nitrogen dioxide appeared to be a major risk factor for lung function
decreases in these tunnel construction workers, although other agents may have [...]