大同市大气SO_2与5岁以下儿童呼吸系统疾病住院的浓度-反应关系研究

目的研究大气SO_2水平与5岁以下儿童呼吸系统疾病每日住院人数的浓度-反应关系。方法住院数据来自2005—2006年大同市主要的9所医院的电子病历首页,空气质量数据来自市内3个空气监测点,气象数据来自山西省气象局。用广义相加模型(GAM)建立浓度-反应关系;用多重结构断裂点检测法确定浓度-反应关系曲线上的拐点;用约束性分段线性函数估计相对危险度。结果大气SO_2与5岁以下儿童呼吸系统疾病日住院人数的浓度-反应关系主要呈非线性相关,曲线呈C、S和J三种形状。关于滞后效应,整个研究期和非采暖期均只有当天(lag0)分析结果有统计学意义,SO_2每升高10μg/m~3,5岁以下儿童呼吸系统疾病住院人数分别增加1.50%和2.93%;采暖期在滞后3 d(lag3)、5 d(lag5)、6 d(lag6)分析结果有统计学意义,在滞后3 d(lag3)效应最强,SO_2每升高10μg/m~3,5岁以下儿童呼吸系统疾病住院人数增加2.08%。关于平均效应,整个研究期和采暖期多数曲线分析结果有统计学意义,且表现为危险度随平均天数增大而增大的趋势,7 d移动平均(avg06)SO_2每升高10μg/m~3,5岁以下儿童呼吸系统疾病住院人数分别增加1.35%和1.60%;非采暖期分析结果均无统计学意义。结论大气SO_2浓度的升高可以导致儿童呼吸系统疾病住院人数增加,浓度-反应关系主要呈曲线相关。

Concentration-response function between sulfur dioxide and respiratory disease hospital admissions of children in Datong,China

Objective To describe the characteristics of concentration-response function between sulfur dioxide and respiratory disease hospital admissions of children.Methods Medical abstract records were collected from nine major hospitals in Datong during the period from 2005 to 2006.Air pollution data were collected from three local environmental monitoring points,and the weather data were from Shanxi Meteorology Agency.Generalized additive models (GAM) with log link and Poisson error was used to estimate the shape of the concentration-response function.Constrained piecewise linear function was used to estimate the relative risk,with change points dynamically estimated by structural-change-detection algorithm.Results Three shapes of concentration-response curves were identified:C,S,and J.For lag influence,in the whole period and non-heating period,only lag0 showed the statistical significance,the excessive risk of which were 1.50％ and 2.93％ associated with the increase of 10 μg/m3 SO2;In the heating period,lag3,lag5 and lag6 showed the statistical significance,the strong effect phase was lag3,the excessive risk was 2.08％ associated with the increase of 10 μg/m3 SO2.For average influence,in the whole period and heating period,most of the results showed the statistical significance and there was a trend of risk increases with the average days increases,the excessive risk of which were 1.35％(avg6) and 1.60％(avg6) associated with the increase of 10 μg/m3 SO2.In the non-heating period,there was no significant.Conclusions Exposure to SO2 was significantly associated with daily respiratory disease hospital admissions of children.The shape of concentration-response function is nonlinear.