Effects of ambient air pollution on lung function growth in Chinese schoolchildren

SummaryObjectiveTo evaluate the adverse effect of exposure to air pollution on lung function growth in school-aged children.MethodsA cohort of 1983 children from three districts in Guangzhou, China was followed-up for 6 months. The children performed pulmonary function tests twice, and their parents reported the child’s respiratory symptoms by self-administered questionnaires in both surveys.ResultsThe annual mean concentrations of air pollutants for the past 5 years for particulate matter less than 10 microns in diameter (PM10), nitrogen (NO2), and sulfur dioxide (SO2) were respectively: 96.1 μg/m3, 76.0 μg/m3, and 65.7 μg/m3 in the highly-polluted district (HPD), 80.3 μg/m3, 67.6 μg/m3, and 54.5 μg/m3 in the moderately-polluted district (MPD), and 80.0 μg/m3, 48.1 μg/m3, and 52.2 μg/m3 in the least-polluted district (LPD).After adjustment for potential confounders, significant deficits were found in the annual growth rates of forced expiratory flows at 25% (FEF25), and between 25% and 75% (FEF25–75) in boys and FEF25 in girls (In boys, for FEF25, −0.136 l/s, p = 0.008 in MPD and −0.153 l/s, p = 0.004 in HPD, respectively; for FEF25–75, −0.176 l/s, p = 0.013 in MPD and −0.167 l/s, p = 0.021 in HPD, respectively. In girls, for FEF25, −0.123 l/s, p = 0.043 in HPD), using LPD as the reference. Deficits in the annual growth rate of forced expiratory volume in 1 s (FEV1) were also negatively associated with air pollution in boys (−0.063 L, p = 0.032 in HPD).ConclusionsThe study adds more evidence that exposure to air pollution has adverse effects on lung function growth in schoolchildren.