超重肥胖对PM2.5短期暴露与儿童青少年肺活量关联的修饰效应

  目的  分析PM_2.5短期暴露与儿童青少年肺活量关联及其超重肥胖修饰效应，为中小学生合理安排室外活动和加强空气污染防护提供科学依据。  方法  选取2017—2018年北京市中小学生年度健康体检数据中数据合格的学生1 036 273名为研究对象；采用反距离加权插值法得出研究对象所处区域的气象要素与空气质量；采用线性混合效应模型估计PM_2.5短期暴露对肺活量7 d内的单独滞后效应与平均滞后效应，分析超重肥胖对PM_2.5的短期暴露与儿童青少年肺活量关联的修饰效应。  结果  2017年9月1日至2018年6月30日，北京市PM_2.5平均质量体积浓度为66.36 μg/m3；研究对象超重肥胖检出率为33.38%，平均肺活量为(2 286.72±956.77)mL。PM_2.5对肺活量的单独滞后效应lag6时最大，即PM_2.5日均浓度每增长10 μg/m3与儿童青少年肺活量降低2.81(95%CI=2.60~3.03) mL显著相关。PM_2.5对肺活量的平均滞后效应lag07时最大，即PM_2.5滑动平均质量体积浓度每增长10 μg/m3与儿童青少年肺活量降低5.82(95%CI=5.37~6.27) mL显著相关。超重肥胖的儿童青少年对PM_2.5短期暴露引起的肺活量下降易感性更高(P＜0.01)。  结论  PM_2.5短期暴露与儿童青少年肺活量呈负相关，且存在滞后效应，超重肥胖的儿童青少年在PM_2.5短期暴露后肺活量下降更显著。

Effect modification of overweight and obesity on the relationship between short-term PM2.5 exposure and vital capacity in children and adolescents

  Objective  To analyze the relationship between short-term exposure of PM_2.5 and the vital capacity of children and adolescents and the modification effect of overweight and obesity, and to provide a scientific reference for appropriate outdoor activities and strengthening prevention of air pollution.  Methods  A total of 1 036 273 students who qualified in the annual health examination data of primary and secondary school students in a city from 2017 to 2018 were selected; the meteorological factors and air quality of the study area were obtained by inverse distance weighted interpolation method; the generalized linear mixed model was used to estimate the individual lag effect and average lag effect of PM_2.5 short-term exposure on lung capacity with in 7 days, and to analyze the modification effect of overweight and obesity on the relationship between short-term PM_2.5 exposure and vital capacity in children and adolescents.  Results  From September 1, 2017 to June 30, 2018, the average PM_2.5 concentration in this city was 66.36 μg/m3, the detection rate of overweight and obesity was 33.38%, and the average lung capacity was (2 286.72±956.77)mL. The single lag effect of PM_2.5 on vital capacity was the biggest when lag6, the average daily PM_2.5 concentration increased by 10 μg/m3 and the decrease of vital capacity of children and adolescents by 2.81(95%CI=2.60-3.03)mL. The average lag effect of PM_2.5 on lung capacity was the largest when lag07, the average concentration of PM_2.5 sliding was significantly correlated with the decrease of lung capacity of children and adolescents by 5.82(95%CI=5.37-6.27)mL every 10 μg/m3 increase. The prevalence of PM_2.5 short-term exposure to pulmonary capacity decreased in overweight and obese children and adolescents was higher (P < 0.01).  Conclusion  The short-term exposure of PM_2.5 has a significant negative correlation with the lung capacity of children and adolescents, and there is a lag effect. The decrease of the vital capacity of overweight and obese children and adolescents after PM_2.5 short-term exposure is more significant.