上海市大气污染对小学生肺功能小气道指标的急性效应研究

目的 分析上海市复合型大气污染对儿童肺功能小气道指标的急性影响。方法 在上海市内环、中环和外环各选择一所小学（A、B和C），每所学校各随机抽取3~5年级一个班级学生为研究对象（共233人）；A、B两校于2013年12月和C校于2014年12月测试肺功能3次，各校分别于次年5-6月测试第4次肺功能。同时收集同期三校就近环境空气质量监测点大气细颗粒物（PM_2.5）、可吸入颗粒物（PM₁₀）、二氧化硫（SO₂）和二氧化氮（NO₂）污染物数据和气象监测数据；采用线性混合效应模型分析大气污染对肺功能小气道指标的影响。结果 控制气象因素和个体因素后，PM_2.5、PM₁₀滞后2 d和累计滞后2 d、SO₂累计滞后2 d和NO₂检测当日浓度每增加一个四分位间距（IQR），儿童25%肺活量最大呼吸流速（MEF_25%）、50%肺活量最大呼吸流速（MEF_50%）、75%肺活量最大呼吸流速（MEF_75%）和用力呼气中段流速（FEF_25%~75%）均有不同程度的降低（P<0.05或P<0.01）；双污染物模型分析显示SO₂和NO₂分别叠加PM_2.5和PM₁₀污染时，滞后效应值大于SO₂和NO₂单独存在时（P<0.05）。结论 上海市大气污染物短期暴露与儿童肺功能小气道指标变化呈负相关，并存在滞后效应及累计滞后效应。

Acute effect of ambient air pollution on small airway lung functions among school children in Shanghai

Objective To study the acute effects of compound ambient air pollution on small airway lung functions among school children in Shanghai. Method A longitudinal survey on lung functions was conducted among 233 school-children from three schools (A, B and C, located in inner-ring, mid-ring and outer-ring areas). Lung function test was performed once a week for 3 times respectively, among children in school A and B in Dec. 2013 and in school C in Dec. 2014. The fourth lung function test was tested in Jun. 2014 and May 2015 in the respective schools. Results from the lung function would include items as:forced mid-expiratory flow at 25% of forced vital capacity (MEF_25%), mid-expiratory flow at 50% of forced vital capacity (MEF_50%), mid-expiratory flow at 75% of forced vital capacity (MEF_75%) and mid-expiratory flow between 25% and 75% of the forced vital capacity (FEF_25%-75%). Data regarding the daily air quality real-time of PM_2.5, PM₁₀, SO₂ and NO₂ in Dec. 2013, Dec. 2014, Jun. 2014 and May. 2015 from the three environmental monitoring spots and meteorological data from the Shanghai Meteorological Service system which were physically close to the three schools, were collected simultaneously. Linear mixed effect model was used to examine the levels of correlation between lung function indicators and ambient air pollutants. Results When confounding factors on meteorology and individuals were controlled, the lag effects and accumulated lag effects were found to have existed between the internal quarter rang (IQR) concentration of PM_2.5 and PM₁₀ in lag2 day and lag02 days, IQR concentration of SO₂ in lag02 day and IQR concentration of NO₂ lag0 day, when small airway lung functions like MEF_25%, MEF_50%, MEF_75% and FEF_25%-75%(P<0.05) were inspected. Results from the two air pollutants model analysis showed that SO₂ and NO₂ presenting interactive effects with PM_2.5, PM₁₀ and lag effects more significant than the individual SO₂ and NO₂, respectively (P<0.05). Conclusion Contents on the ambient air pollutants as PM_2.5, PM₁₀, SO₂ and NO₂ were negatively associated with the lung functions in the small airways of children, in Shanghai.