Increased Decline in Pulmonary Function Among Employees in Norwegian Smelters Reporting Work-Related Asthma-Like Symptoms

J Occup Environ Med. 2015 Sep;57(9):1004-8. doi: 10.1097/JOM.0000000000000518.


Objective: To investigate associations between work-related asthma-like symptoms (WASTH) and annual pulmonary function decline among employees of 18 Norwegian smelters.

Methods: A 5-year longitudinal study in which WASTH was defined as a combination of dyspnea and wheezing that improved on rest days and vacation.

Results: A total of 12,966 spirometry examinations were performed in 3084 employees. Crude annual decline in forced expiratory volume in 1 second (FEV1) (dFEV1) was 32.9 mL/yr (95% confidence interval, 30.5 to 35.3), and crude annual decline in forced vital capacity (FVC) (dFVC) was 40.9 mL/yr (37.8 to 43.9). After adjustment for relevant covariates, employees reporting WASTH showed higher dFEV1 by 16.0 m:/yr (3.4 to 28.6) and higher dFVC by 20.5 mL/yr (6.0 to 35.0) compared with employees not reporting WASTH.

Conclusion: Work-related asthma-like symptom was associated with greater annual declines in FEV1 and FVC, indicating a restrictive pattern.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Asthma / epidemiology
  • Female
  • Humans
  • Longitudinal Studies
  • Lung Diseases / epidemiology*
  • Lung Diseases / etiology
  • Male
  • Metallurgy*
  • Middle Aged
  • Norway / epidemiology
  • Occupational Diseases / epidemiology*
  • Occupational Exposure / adverse effects*
  • Respiratory Function Tests
  • Young Adult