The effect of industry-related air pollution on lung function and respiratory symptoms in school children

Background: Heavy industry emits many potentially hazardous pollutants into the air which can affect health. However, the effects of air pollution from heavy industry on lung function and respiratory symptoms have been investigated scarcely. Our aim was to investigate the associations of long-term air pollution from heavy industry with lung function and respiratory symptoms in school children. Methods: A cross-sectional lung function study was conducted among school children (7-13 years) in the vicinity of an area with heavy industry. Lung function measurements were conducted during school hours. Parents of the children were asked to complete a questionnaire about the health of their children. A dispersion model was used to characterize the additional individual-level exposures to air pollutants from the industry in the area. Associations between PM2.5 and NOx exposure with lung function and presence of respiratory symptoms were investigated by linear and/or logistic regression analysis. Results: Participation in the lung function measurements and questionnaires was 84% (665/787) and 77% (603/787), respectively. The range of the elevated PM2.5 and NOx five years average concentrations (2008-2012) due to heavy industry were 0.04-1.59 mu g/m(3) and 0.74-11.33 mu g/m(3) respectively. After adjustment for confounders higher exposure to PM2.5 and NOx (per interquartile range of 0.56 and 7.43 mu g/m(3) respectively) was associated with lower percent predicted peak expiratory flow (PEF) (B -2.80%, 9596CI -5.05% to -0.55% and B -3.67%, 95%CI -6.93% to -0.42% respectively). Higher exposure to NOx (per interquartile range of 7.43 mu g/m(3)) was also associated with lower percent forced vital capacity (FVC) and percent predicted forced expiration volume in 1 s (FEV1) (B -2.30, 95% CI -4.55 to -0.05 and B -2.73, 95%CI -5.21 to -0.25 respectively). No significant associations were found between the additional exposure to PM2.5 or NOx and respiratory symptoms except for PM2.5 and dry cough (OR 1.40, 95%CI 1.00 to 1.94). Conclusion: Exposure to PM2.5 and NOx from industry was associated with decreased lung function. Exposure to PM2.5 was also associated with parents' reports of dry cough among their children.