Working in a petroleum refinery predicts lower lung function parameters

Abstract

Aim of the study. To examine differences in lung function between petroleum refinery workers and office workers and to evaluate working in petroleum refinery as a predictor of the values of lung function parameters. Methods. We performed a cross-sectional study including 90 male petroleum refinery workers, aged 32-60 years. In addition, 40 male office workers, aged 47-59 years were examined as a control. Evaluation of examined subjects included completion of a questionnaire on general and respiratory symptoms in the last 12 months and lung function testing (all parameters expressed in %predicted). Several multiple regression models were tested to examine the associations of working in a petroleum refinery to lung function parameters controlling for age, duration of employment, exposure duration, daily smoking, life-time smoking, and number of cigarettes per day. Results. Mean values of lung function parameters (FVC, FEV1, MEF75, MEF50 and MEF25) were similar in both groups. Mean FEV1/FVC value was significantly lower in petroleum refinery workers (83.13 ± 7.16) than in controls (87.1 ± 7.44) (t=-2.88; p=0,005). Multiple regression analysis showed that daily smoking (β = -.803) and cigarettes/day (β = -.507) were significant predictors of lower FEV1 (R² = .09, ΔR² = .08, ΔF=1.97, p=0.015). Working in a petroleum refinery (β = -.228) negatively predicted FEV1/FVC (R² = .097, ΔR² = .047, ΔF=6.36, p=0.013). Conclusion. Our data suggest important role of specific occupational exposure, daily smoking, and number of cigarettes per day in the development of reduced lung function.