Traffic proximity and lung function. A case-control study in asthmatic children

Introduction: Respiratory conditions are strongly dependent on air pollution. Urban areas are typically characterized by risky environmental conditions. Objectives: To analyze the effect of traffic proximity on asthma and to explore the relationship between level of traffic proximity and lung function in asthmatic and non- asthmatic children. Methods: A case-control study on children visited for suspected respiratory diseases at IBIM from 2011 to 2014 was performed. All the children have been geocoded according to their residence address. Exposure to traffic air pollution was assessed through determination of number and types of streets in proximity of the place of residence. The relationship between air pollution, lung function and other variables collected through laboratory survey and functional tests was explored. Results: There were 433 children: 22.6% with diagnosis of persistent asthma, 25.9% with intermittent asthma, and 51.5% without an asthma diagnosis (i.e. controls). Level of exposure to traffic conditions did not show significant differences between cases and controls at a distance of 100, 200 and 500 meters from the place of residence. Association between living in proximity to HTR and worst lung function resulted only for children with persistent asthma (OR=3.48; CI= 2.14; 5.66). Conclusion: Our preliminary results do not show differences in environmental conditions as measured through traffic proximity among persistent asthmatics, intermittent asthmatics and controls. However, association between lung function and traffic proximity is observed for asthmatic children. These results indicate that living in proximity to HTR can be a determinant for worst lung functions among asthmatic children.