Objective: To assess whether air pollution by traffic was related to lung function and chronic respiratory symptoms in children living.
Design: Descriptive.
Setting: The province of South Holland, the Netherlands.
Methods: In the period May through July of 1995 pulmonary function tests and questionnaires were obtained from 1,092 and 1,068 children respectively in six city districts near busy motorways in the province of South Holland. In the same period, indoor measurements were performed at 12 schools of NO2, black smoke and PM10 dust density. Lung function data were analysed by multiple linear regression and respiratory symptoms were analysed by multiple logistic regression. As independent variables, distance between motorway and home, passenger car traffic density and lorry traffic density on the motorway, and black smoke and NO2 concentrations in schools were taken.
Results: Significant differences in lung function and respiratory symptoms were found between children living in different city districts. Lung function as well as symptoms were associated with lorry traffic density on the motorway. The validity of these findings was supported by associations between black smoke concentrations (representative for diesel soot) and lung function as well as respiratory symptoms. In contrast, there was no association between passenger car traffic counts or NO2 and lung function or respiratory symptoms.
Conclusion: The results suggest that air pollution by lorry traffic can lead to reduced lung function and to an increased prevalence of chronic respiratory symptoms in children living near major motorways.