Association between air pollution and lung development in schoolchildren in China

Background China has been facing nationwide air pollution at unprecedented high levels primarily from fossil-fuel combustion in the past decade. However, few studies have been conducted on the adverse effect of severe air pollution on lung development in school-age children. Methods Using wellness check and air pollution data from 2014 to 2017, we conducted a retrospective analysis of lung development in 21 616 school-age children from Shijiazhuang and Qingdao from North China with severe vs mild air pollution. Linear mixed effects model was performed to assess the effect of air pollution on forced vital capacity (FVC) growth. Results Exposure to severe air pollution was associated with a dramatic reduction in annual FVC growth rate (-71.3 mL, p < 0.001). In addition, every 10 mu g/m(3) increase in annual PM2.5 level was associated with a reduction of annual FVC growth by 12.2 mL (p < 0.001). Sex discrepancy (boys vs girls) in FVC growth was greater in Qingdao (35.4 mL/year, 95% CI: 26.0 to 44.7) than in Shijiazhuang (19.8 mL/year, 95% CI: 9.3 to 30.3) (p for interaction=0.063). Exposure to indoor coal- or wood-burning stove heating (-79.4 mL, p < 0.001) and secondhand smoke at home (-59.3 mL, p = 0.003) were inversely associated with FVC growth. Conclusion Our study raised serious alarm over the threat of severe air pollution to lung development in school-age children. Sex discrepancy in lung development was reduced dramatically in heavily polluted area.