Long-term exposure to air pollution and school children's respiratory health and lung function growth: A 1-year prospective cohort study in Guangzhou, China

To investigate the effects of long-term exposure to outdoor air pollution on school children's respiratory health and lung function growth, a 1-year prospective cohort study was conducted in three districts with different air pollution levels in Guangzhou, China.;The baseline study was carried out from September to November 2006, a total of 2,179 children were included in the final analysis. After adjustment for confounders, children living in the HPD had increased risks for several respiratory symptoms/diseases, when compared with those in the LPD. Children in the LPD had significantly lower lung functions than those in the other two districts.;The investigation was repeated from April to June in 2007. Among 2,113 children who participated in the follow-up study, 1,983 children were included in the analysis. Compared to those in the LPD, significantly increased risks were found for several respiratory symptoms/diseases in children living in the HPD. Children living in the higher polluted districts had significant relative risks (RRs) for allergic rhinitis (RRMPD=2.62; 95% CI: 1.49-4.60; RRHPD=2.03; 95% CI: 1.14-3.63). A significant RR was found for sinusitis in the children living in the HPD (RR=3.38; 95% CI: 1.06-10.72), as well as for sneeze with itchy-watery eyes in girls in the HPD (RR=4.57; 95% CI: 1.01-20.66). After controlling for confounding factors, children in the LPD presented significantly lower lung function than those in the higher polluted districts. In comparison with HPD, children in the MPD had higher but insignificant means for most of the lung function indices.;In analysis of the lung function growth, boys living in the LPD had significantly higher growth rates for FEF25-75% and FEF25% than those in the other two districts, as well as higher FEV1 than the HPD. The growth rate of FEF25% in girls living in the LPD was significantly higher than that of girls in the HPD.;In summary, the ambient air pollution level was significantly associated with increased risks for the prevalence and incidence of respiratory symptoms and diseases in a 1-yr prospective study in Guangzhou, China. Long-term exposure to air pollution had significantly negative effects on the development of children's lung function.