2014—2015年合肥市大气PM_(2.5)污染对儿童门诊量影响的时间序列分析

Influence of ambient PM_(2.5) pollution on clinic visits of children in Hefei in 2014-2015:a time series analysis

目的探讨合肥市大气PM_(2.5)日均浓度对合肥市儿童门诊量的影响。方法分别从合肥市气象局、合肥市环保局获得2014—2015年合肥市全年气象、环保资料,从合肥市滨湖医院、合肥市第二人民医院医院信息系统(HIS)获取同期儿童门诊资料。采用基于Poisson回归的广义相加模型(GAM)控制时间趋势、温度和相对湿度、星期几效应、法定节假日等因素进行PM_(2.5)对儿童门诊量影响的时间序列分析,分析PM_(2.5)浓度对当日、滞后1~7 d效应(lag0~lag7),以及移动平均浓度对滞后1~7 d的累积滞后效应(lag1~7)。结果 2014—2015年合肥市PM_(2.5)平均浓度为(73.1±43.5)μg/m3,是GB 3095—2012《环境空气质量标准》二级标准年均值(35μg/m3)的2.1倍,2年共有267 d(占36.6%)的PM_(2.5)日均浓度超过国家二级标准24 h均值(75μg/m3)。GAM模型发现PM_(2.5)对合肥市滨湖医院、合肥市第二人民医院的儿科门诊均有显著影响,其中对总门诊量当日的影响最大,合肥滨湖医院、合肥市二院的ER分别为0.65%(95%CI:0.49%~0.81%)、0.92%(95%CI:0.70%~1.13%);对合肥滨湖医院儿童呼吸系统当日的门诊量影响最大[ER=0.78%(95%CI:0.58%~0.99%)],对合肥市二院儿童呼吸系统滞后2 d门诊量影响最大[ER=0.90%(95%CI:0.63%~1.18%)]。采用PM_(2.5)移动平均浓度分析累积滞后效应时发现,PM_(2.5)污染物对儿童的总门诊量和呼吸系统门诊量均有累积滞后效应,两医院的总门诊和呼吸系统门诊量均在累积滞后7 d(lag0~7)时ER最高,总门诊ER分别为1.60%(95%CI:1.32%~1.87%)、2.62%(95%CI:2.25%~3.00%),呼吸系统门诊ER分别为1.83%(95%CI:1.48%~2.19%)、3.19%(95%CI:2.7%~3.66%)。未发现PM_(2.5)浓度对儿童循环系统门诊量有显著影响。结论 2014—2015年空气污染对合肥地区儿童门诊量有显著影响,PM_(2.5)浓度增加会导致儿童总门诊、儿童呼吸系统门诊的门诊量增加。

Objective To evaluate the relationship between ambient PM_（2.5）pollution and the number of clinic children visits in Hefei during 2014-2015. Methods Data on environmental factors and meteorological factors from January 1, 2014 to December31, 2015 was obtained from the local municipal environmental monitoring center and meteorology bureau of Hefei respectively.Data on clinic visits of children was collected from Hefei Binhu Hospital and Hefei NO.2 Hospital. Controlling temporal trends,temperature and relative humidity, day of week, weekend, holidays and other factors, generalized additive model based on Poisson regression was applied to analyze the lag effect（lag0-lag7） and accumulative effects（lag1-7） of ambient PM_（2.5）pollution on the number of outpatient in the hospital. Results The average concentration of PM_（2.5）in Hefei city, 2014-2015 was（73.1±43.5） μg/m3, which was 2.1 times as high as the annual mean concentration of grade two standard in GB3095-2012 Ambient Air Quality Standard（35μg/m3）, and the daily average concentration of PM_（2.5）in 267 days（36.6%） was higher than the 24-hour average level of grade two standard（75 μg/m3）. The GAM model showed that PM_（2.5）concentration had the significantly impact on the number of children＇s total and respiratory clinic visits. The most obvious effects on the total amount of the clinic visits in Hefei Binhu Hospital and Hefei NO.2 Hospital was observed in lag0（Hefei Binhu Hospital： ER=0.65%, 95%CI： 0.49%-0.81%;Hefei NO.2 Hospital： ER =0.92 %,95% CI：0.70%-1.13%）. On the respiratory system, the greatest impact in Hefei Binhu Hospital was observed in lag0 [ER=0.78%（95%CI： 0.58%-0.99%）], and lag2 in Hefei NO.2 Hospital [ER=0.90%（95%CI：0.63%-1.18%）]. By moving average concentration analysis there was a cumulative lag effect between PM_（2.5）concentrations and the amount of children＇s total and respiratory visits. The highest influence between PM_（2.5）and accumulative effects for children＇s total visits and respiratory visits in two hospitals were all occurred in lag0-7： ERs were 1.60%（95% CI：1.32%-1.87%） and2.62%（95% CI：2.25%-3.00%） for total visits, and 1.83%（95% CI：1.48%-2.19%） and 3.19%（95% CI： 2.7%-3.66%） for respiratory visits respective.There was no significantly influence between the PM_（2.5）concentrations and the number of clinic visits on children＇s circulatory system. Conclusion From 2014 to 2015, air pollution presents significant impact on children＇s clinic visits. Higher ambient PM_（2.5）pollution level may increase children＇s total clinic visits and respiratory visits.