西安市大气PM_(2.5)短期暴露对小学生肺功能的影响

Impact of short⁃term exposure to atmospheric PM_(2.5)on lung function in primary school students in Xi’an City

目的探讨西安市大气PM_(2.5)短期暴露对小学生肺功能的影响,为空气污染治理及保护儿童健康提供科学依据。方法于2017年在西安市雁塔区(轻污染区)和莲湖区(重污染区)2个国家监测点内各选择1所小学(A校与B校),采用整群随机抽样方法抽取三~五年级小学生,分别于采暖前后开展一次肺功能检测。同时收集检测当天及前29 d的PM_(2.5)日均浓度,采用多元线性回归分析PM_(2.5)暴露对小学生肺功能指数的影响。结果2所小学采暖期PM_(2.5)的日均浓度分别为132.80μg/m^(3)和110.00μg/m^(3),均超过二级浓度限值;采暖期PM_(2.5)的日均浓度均高于非采暖期(P<0.05)。在控制性别、年龄等影响因素后,PM_(2.5)暴露对B校学生肺功能指数FVC和FEV1的影响有统计学意义(P<0.05),采暖期肺功能指数FVC相较于非采暖期平均降低0.080,肺功能指数FEV1平均降低0.056;PM_(2.5)暴露对A校学生肺功能指数的影响无统计学意义。结论大气PM_(2.5)短期暴露对处于重污染区的B校小学生肺功能指数有影响,相关部门应针对重点区域加大空气污染治理力度。

Objective To explore the impact of short⁃term exposure to atmospheric PM_(2.5) on the lung function in pri⁃mary school students in Xi’an City,so as to provide scientific evidence for air pollution control and protection of children’s health.Methods In 2017,two primary schools(School A and School B)were selected in the two national monitoring points of Yanta District(a lightly polluted area)and Lianhu District(a heavily polluted area)of Xi’an City,and the cluster random sampling method was used to select 3-5th grade primary school students,and a pulmonary function test was carried out before and after heating.At the same time,the daily average concentration of PM_(2.5) on the day of the test and the previous 29 days was collected.Multiple linear regression was used to analyze the impact of PM_(2.5) exposure on the lung function index of primary school students.Results The average daily concentrations of PM_(2.5) in the heating period of the two primary schools were 132.80μg/m^(3) and 110.00μg/m^(3),respectively,which exceeded the secondary concentration limit;the daily average con⁃centration of PM_(2.5) during the heating period was higher than that of the non⁃heating period(P<0.05).After controlling for gender,age and other influencing factors,PM_(2.5) exposure had statistically significant impacts on the lung function index FVC and FEV1 of School B students(P<0.05).The lung function index FVC during the heating period was 0.080 lower than that of the non⁃heating period and the lung function index FEV1 decreased by an average of 0.056;PM_(2.5) exposure had no statisti⁃cally significant impacts on the lung function index of School A students.Conclusions Short⁃term exposure to atmospheric PM_(2.5) has an impact on the lung function index of School B students in the heavily polluted area.Relevant departments should strengthen the control of air pollution in key areas.