Traffic-related Air Pollution and Personal Exposure to Nitrogen Oxides in School Children in Beijing

Abstract

O-31A6-1 Background/Aims: Several studies have shown association between traffic-related nitrogen oxides (NOx) pollution and adverse health effects in children. Most of these studies, however, used ambient or indoor NOx concentrations as surrogate of personal exposure. The studies on personal exposure to NOx in children are still limited. In this study, we evaluated personal exposure to NOx, nitrogen dioxide (NO2), and nitric oxide (NO) in children from 2 primary schools located in 2 areas in Beijing with different levels of traffic-related air pollution. Methods: A study of personal exposure to NOx, NO2, and NO was conducted in 30 children from a school near a main road with high traffic density (School 1) 4 times from 2007 to 2008, and in 40 children from a school (School 2) located far from the main road in 2008, respectively. Personal exposure to NOx, NO2, and NO were measured with passive samplers. Repeated Measures Test in General Linear model was used to analyze the differences of exposures among the 4 periods in children from School 1. And the differences between 2 schools were analyzed by Mann-Whitney U Rank test. Results: In children from School 1, the highest exposure to NO2 was observed in January 2008, whereas there was no significant difference among the other 3 periods. The lowest and highest exposures to NO and NOx were seen in October and April 2008, respectively. There was no significant difference between the other 2 periods. At the same period of investigation, personal exposure to NO2, NO, and NOx in children from School 1 were 99%, 145%, and 129% higher than those in children from School 2, respectively. Conclusion: Our results suggested that traffic-related air pollution significantly contributed to the personal exposure to NOx, NO2, and NO in school children in Beijing.