The association of air pollution with height: Evidence from Hong Kong's "Children of 1997" birth cohort

ObjectivesWithin populations, height is positively associated with economic success and in economically developed populations inversely associated with health. Recent studies also suggest air pollution may result in higher bone turnover markers among children, which may affect growth. However, few studies have investigated the effect of air pollution on height or growth rate. We therefore assessed the associations of several air pollutants with height at different ages. MethodsWe simultaneously assessed associations of particulate matter with a diameter of 10 micrometers or less (PM10), sulfur dioxide (SO2), nitric oxide (NO), and nitrogen dioxide (NO2) in utero, in infancy, and in childhood with height at different ages (approximate to 9, approximate to 11, approximate to 13, and approximate to 15 years), in a population-representative birth cohort Children of 1997 (n=8327) from the developed non-Western setting of Hong Kong with relatively high air pollution and short children, using partial least square regression. ResultsAfter considering multiple comparison, higher SO2 in childhood was associated with shorter height at approximate to 13 years (-0.20 cm, 99% CI -0.32 to -0.06). This difference was not evident at approximate to 15 years. ConclusionsThese observations suggest that air pollution may affect the trajectory of growth and development rather than final height, with corresponding implications for health in later life.