Geographic variation in Chinese children' forced vital capacity and its association with long-term exposure to local PM10: a national cross-sectional study.

The purpose of this study was to estimate the association between Chinese children's forced vital capacity (FVC) and particulate matter with aerodynamic diameter ≤10 μm (PM10). The FVC data of 71,763 children aged 7 to 18 was collected from 2010 Chinese National Survey on Students' Construction and Health (CNSSCH). The local annual average concentration of PM10, relative humidity, ambient temperature, and other air pollutant data of 30 cities was collected from China Meteorological Administration and Ministry of Environment Protection of China. Then, we used generalized additive model (GAM) to estimate the association between children's FVC and PM10. The obvious geographic variation in FVC was found in children of 30 Chinese cities ranging from 1647 ml in Xining to 2571 ml in Beijing. The annual average concentration of PM10 was also different, ranging from 40 μg/m3 in Haikou to 155 μg/m3 in Lanzhou. After adjusted individual characteristics, socioeconomic conditions, ambient temperature, relative humidity, and other air pollutants (e.g., NO2 and SO2) in the generalized additive model, we found that the increase of PM10 was associated with decrease of FVC in Chinese children. A 10-μg/m3 increase of PM10 was associated with 1.33-ml decrease in FVC (95% confidence interval: -2.18 to -0.47). We also found a larger effect estimate of PM10 on FVC in boys than that in girls. Consistent associations were found in both physically inactive and active children. The increase of PM10 was associated with decrease of children's FVC. We should develop proper public health policy to protect children's respiratory health during growth and development in polluted areas.