Exposure to vehicular traffic is associated to a higher risk of hospitalization for bronchiolitis during the first year of life

BACKGROUND: The most common cause of hospitalization for children younger than age one is bronchiolitis. Several prenatal and environmental risk factors may affect the incidence of hospitalization for bronchiolitis. The aim of this study was to investigate the relation between exposure to vehicular traffic and the incidence of hospitalization for bronchiolitis in children during their first year of life in Italy. METHODS: A multicenter prospective birth cohort study, where equal numbers of newborns of 33-34, 35-37 and .38 wGA were recruited at birth (1814 children) in 30 Italian neonatology units. Two interviewer-administered questionnaires were used to collect data. The first interview was carried out at the end of the Italian epidemic season. The second interview was carried out when the child was one year old. Data on possible prenatal, perinatal, and postnatal/environmental risk factors and on vehicular traffic density in the zone of residence were collected. On each interview, parents were also asked about any hospitalizations of the child. The outcome measure was the hospitalization for bronchiolitis (International Health Service ICD-9 code 466). RESULTS: Univariate analysis demonstrated that exposure to air pollution due to vehicular traffic, was significantly associated with an increased risk of hospitalization for bronchiolitis. The adjusted risk from logistic regression model confirmed that children exposed to air pollution due to vehicular traffic were at increased risk of hospitalization for bronchiolitis. CONCLUSIONS: Exposure to air pollution due to vehicular traffic may increase the risk of hospitalization for bronchiolitis in the first year of life.