Exposure to Polycyclic Aromatic Hydrocarbons, but Not to Dust or Fluorides, in the Norwegian Aluminum Industry Is Associated With Accelerated Annual Decline in Lung Function

ABSTRACT Purpose The association between development of chronic airflow limitation and exposures in the aluminum industry is unknown. In a prospective study with nearly 10 years of annual measurements of forced expiratory volume in 1 s (FEV1) and forced vital Capacity (FVC) and concurrent estimates of exposure to dust, total fluorides (TotF) and polycyclic aromatic hydrocarbons (PAH) we investigated the relationship between each of these exposures and annual decline in FEV1 (dFEV1) and FVC (dFVC). Methods Estimates of exposure to dust, TotF, and PAH were obtained from random samples of 8‐h shifts using personal samplers at each of seven Norwegian aluminum plants. A total of 18,332 measurements were used to create a job‐exposure matrix. The total number of available spirometries was 20,712 in 3872 workers. Data were analyzed using linear mixed modeling with inverse probability weights for dropouts. Results We found that dFEV1 and dFVC increased during follow‐up with linear and quadratic components that were modified by PAH exposure. These linear and quadratic components were estimated at 2.5 mL/year ( p = 0.019) and 4.2 mL/year 2 ( p < 0.001) for dFEV1, and −2.6 mL/year ( p = 0.076) and 5.9 mL/year 2 ( p < 0.001) for dFVC, respectively, per quartile increase in PAH exposure. Conclusion We found a significant effect modification of the relationship between dFEV1 and dFVC, and follow‐up time by PAH exposure, indicating that PAH exposure accelerates the annual decline in FEV1 and FVC.