Lung function decline, chronic bronchitis, and occupational exposures in young adults

Rationale: Occupational exposures to vapors, gas, dust, or fumes have been shown to be a risk factor of airway obstruction in cross-sectional studies in the general population. Objectives: Our aim was to study the relationships between specific occupations and occupational exposures during a 9-yr follow-up period and changes in lung function and symptoms of chronic bronchitis. Methods: Subjects from the general population aged 20 to 45 yr were randomly selected in 1991-1993 within the European Community Respiratory Health Survey. Follow-up took place from 1998 to 2002 among 4,079 males and 4,461 females in 27 study centers. A total of 3,202 men and 3,279 women twice completed lung function measurements. Job history during follow-up was linked to a job exposure matrix and consequently translated into cumulative exposure estimates. Main Results: Individuals exposed to dusts, gases, and fumes during the period of follow-up did not have a steeper decline of FEV₁ than did individuals with consistently white-collar occupations without occupational exposures (relative change among men and women, +1.4 and -3.1 ml/yr, respectively; p > 0.2), nor an increase of prevalence or incidence of airway obstruction defined as an FEV₁/FVC ratio of less than 0.7. The incidence of chronic phlegm increased in men exposed to mineral dust (relative risk, 1.94 [1.29-2.91]) and gases and fumes (relative risk, 1.53 [0.99-2.36]), which was not modified by smoking. Conclusion: Occupational exposures to dusts, gases, and fumes occurring during the 1990s are associated with incidence of chronic bronchitis, although these did not impair lung function in a population of relatively young age.