Abstract

Fractional exhaled nitric oxide (FeNO) is now recognised as a surrogate marker of eosinophilic airway inflammation and is affected by several factors, air pollution is an environmental determinant of it. Previous studies provide evidence that children are sensitive to the effects of air pollution. Therefore, the main objective of this study is to determine the effects of ambient air pollution on exhaled NO levels among school children.

From March 2016 to March 2017, a nationwide cross-sectional study was conducted in Taiwan using a modified Chinese version of the International Study of Asthma and Allergies in Childhood (ISSAC-C) questionnaire. Children received FeNO measurement in the morning, and inside buildings. Air pollution data were retrieved from air monitoring stations within two kilometre of the schools.

From 37 schools, 3344 students aged 6–15 years were randomly selected as candidates of the study. We complete monitoring data of air pollution, including SO₂, O₃, CO, NO₂, PM_2.5 and PM₁₀. Our preliminary results showed that the levels of FeNO were significantly (p<0.05) associated with average CO (0.48±0.4 ppm), NO (5.48±10.21 ppb), PM2.5 (20.96±14.27 µg/m3), and PM10 (46.44±22.78 µg/m3) concentrations of lag day1. In summary, results indicated that exposure ambient pollutants might affect FeNO levels of schoolchildren. In order to further investigate, multilevel modelling will be used to distinguish the sources of variation in the response. We plan to evaluate variations among children in the first level, and variations among schools in the second level.