Air pollutants and greenspaces exposure, and associations with respiratory health of children

<bold>Background:</bold> Asthma and related respiratory conditions are increasing in urban cities, likewise experiencing increased traffic-related air pollution(TRAP) levels. A cross-sectional study was designed to investigate the association of TRAP on respiratory symptoms and visits made to general practitioners/emergency department/hospitalisation due to acute asthma exacerbations in children and adolescents, and we also aimed to understand whether greenspaces surrounding the schools at Mysore city impacted this association. School neighbourhood characteristics such as distance from major roads, major sources of TRAP, and industries were considered sources of exposure and the Normalised Difference Vegetation Index(NDVI) was used to measure greenspace at 100m and 200m surrounding school. Trucks passing frequency near child’s residence were the surrogate marker used for measuring exposure to heavy TRAP. Mixed-effect logistic regressions were used to understand the association between exposures and respiratory outcomes. <bold>Results:</bold> TRAP exposures due to trucks were associated with allergic rhinitis (AR) in children [ORa=1.396, 95% CI (1.016, 1.920); p=0.040] and adolescents [ORa=1.258, 95% CI (1.032, 1.535); p=0.023], and the areas of low greenspace were associated with increased prevalence of AR and coughing(p<0.05). TRAP exposures and the odds of unplanned visits to emergency department were observed in adolescents. Greenspaces strongly interacted with TRAP and respiratory symptoms, and the effects varied in children and adolescents. <bold>Conclusion:</bold> Study findings suggest that exposure to air pollution in urban areas is increasingly harmful to children and adolescents, while greenspaces can modify the effect.