Effect of traffic proximity of lung function in asthmatic children

Abstract

Introduction Respiratory conditions are strongly dependent on air pollution. Urban areas are typically characterized by risky environmental conditions, especially due to traffic congestion. Indeed, there may be important variations in environmental quality even within urban areas. Objectives To analyze the effect of traffic proximity on asthma and to explore the relationship between level of traffic proximity and lung function in both asthmatic children and non-asthmatic children. Methods A case-control study on children visited for suspected respiratory diseases at IBIM from September 2011 to May 2014 was performed. All the children have been geocoded according to their residence address. After geocoding, level of exposure to environmental conditions was assessed through determination of number and types of streets in proximity of the place of residence. High traffic roads (HTR) were defined as all roads segments with at least 10,000 vehicles per- day. Moreover, the city area has been divided in two main polygons: city centre, North area and suburbs. Their relationship with lung function was explored jointly with other variables collected through questionnaire surveys and laboratory functional tests. As for the lung function, spirometric indices (FEV1; FVC; FEV1/FVC; FEF25-75) were obtained by using a portable spirometer (Pony FX, Cosmed, Italy) and they were expressed as percent predicted using GLI-2012 equation. A measure of restrictive pattern was determined as the ratio FEV1/FVC > LLN and FVC