兰州市空气污染对居民呼吸系统疾病急诊量的影响

目的 探讨兰州市空气污染对不同年龄居民呼吸系统疾病急诊就诊人次影响以及季节性变化,为兰州市呼吸系统疾病的早期预防提供科学依据。方法 收集2013年1月1日至2017年12月31日间兰州市3家甲等医院呼吸系统疾病每日急诊量数据,以及同时间段兰州市大气污染物数据和气象数据。采用广义相加模型控制时间的长期趋势、气象因素、“星期几”效应等混杂因素的影响后,定量分析空气污染物和居民呼吸系统疾病日急诊量的关系,及空气污染物的影响是否存在滞后效应。结果 2013至2017年间,兰州市呼吸系统疾病急诊就诊人次总量为124 871人次,日均69人次(1~367人次/d)。单污染物模型显示:兰州市6种常规空气监测污染物中,PM_2.5、PM₁₀、NO₂、SO₂、O₃8h对呼吸系统疾病急诊人次存在滞后效应,PM_2.5(lag02:t=4.792,P=0.001)、PM₁₀(lag2:t=3.421,P<0.001)、NO₂(lag6:t=3.654,P=0.003)、SO₂(lag06:t=4.712,P<0.001)和O₃8h(lag07:t=3.021,P=0.012)浓度每增加10 μg/m ³,呼吸系统疾病急诊量增加0.900%(95%CI:0.573%~1.249%)、0.083%(95%CI:0.012%~0.153%)、1.293%(95%CI:0.867%~1.720%)、3.851%(95%CI:2.675%~5.041%)和0.737%(95%CI:0.129%~1.348%);CO(lag0;t=3.564,P<0.001)每增加1 mg/m³,呼吸系统疾病急诊量增加2.556%(95%CI:1.493%~3.629%)。性别分层中,冬季时PM_2.5(男:t=3.124,P=0.019;女:t=3.418,P=0.007)、PM₁₀(男:t=2.980,P=0.160;女:t=2.997,P=0.013)、CO(男:t=4.117,P=0.001;女:t=4.629,P<0.001)对女性呼吸系统疾病急诊量的影响大于男性,NO₂(男:t=3.020,P=0.107;女:t=3.006,P=0.128)、SO₂(男:t=4.101,P<0.001;女:t=3.820,P<0.001)、O₃8h(男:t=3.660,P=0.022;女:t=3.517,P=0.018)对男性呼吸系统疾病急诊量的影响大于女性。年龄分层中,冬季时PM_2.5(0~14岁:t=3.520,P=0.008)、PM₁₀(0~14岁:t=3.840,P<0.001)、SO₂(0~14岁:t=4.570,P<0.001)、CO(0~14岁:t=4.102,P=0.002)日均浓度的增加均可导致0~14岁人群呼吸系统疾病急诊量增加;夏季时O₃8h(0~14岁:t=4.210,P<0.001;15~64岁:t=3.807,P=0.001)的日均浓度对0~14岁和15~64岁年龄组呼吸系统疾病急诊量的增加有明显影响,各空气污染物对≥65岁年龄组人群呼吸系统疾病急诊量无明显影响。双污染物分析结果显示,当分别引入其他5种污染物后,PM_2.5、PM₁₀、NO₂、SO₂和CO对人群呼吸系统疾病急诊量的增加有明显影响;引入PM_2.5、NO₂、SO₂和CO后,O₃8h对呼吸系统疾病急诊量较单污染物模型结果有所上升。结论 兰州市6种大气污染物浓度的增加均会导致居民呼吸系统疾病急诊量的增加,且对不同性别、年龄人群和季节的影响模式不同。

Effect of Air Pollution on Emergency Room Visits for Respiratory Diseases in Lanzhou

Objective To explore the effect of air pollution on the number of emergency room visits for respiratory diseases in residents at different ages and its seasonal changes in Lanzhou,so as to provide a scientific basis for the early prevention of respiratory diseases in Lanzhou. Methods The daily number of emergency room visits for respiratory diseases in three class A hospitals in Lanzhou from January 1,2013 to December 31,2017,as well as the air pollutants and meteorological data of Lanzhou in the same period,was collected.After controlling the confounding factors including long-term trend of time,meteorological factors and day-of-week effect using a generalized additive model,we analyzed the relationships between air pollutants and the daily number of emergency room visits for respiratory diseases,and explored whether there was a lag effect of air pollutants.Results From 2013 to 2017,the emergency room visits for respiratory diseases in Lanzhou had a total number of 124 871,with an average of 69(1-367)visits per day.The single pollutant model showed that among the six conventional air pollutants monitored in Lanzhou,PM _2.5,PM₁₀,NO₂,SO₂ and O₃8h had a lag effect on the number of emergency room visits for respiratory diseases.For every 10 μg/m ³ increase in the concentration of PM_2.5 (lag02:t=4.792, P=0.001), PM₁₀ (lag2:t=3.421, P<0.001), NO₂ (lag6:t=3.654, P=0.003), SO₂(lag06:t=4.712, P<0.001)and O₃8h (lag07:t=3.021, P=0.012), the number of emergency room visits for respiratory diseases increased by 0.900%(95% CI:0.573%-1.249%), 0.083%(95% CI:0.012%-0.153%), 1.293%(95% CI:0.867%-1.720%), 3.851%(95% CI:2.675%-5.041%)and 0.737%(95% CI:0.129%-1.348%), respectively.For every 1 mg/m³ increase in the concentration of CO(lag0:t=3.564,P<0.001),the number of emergency room visits for respiratory diseases increased by 2.556% (95%CI: 1.493%-3.629%). In gender stratification, PM_2.5(male:t=3.124, P=0.019;female:t=3.418, P=0.007), PM₁₀(male:t=2.980, P=0.160;female:t=2.997, P=0.013)and CO(male:t=4.117, P=0.001;female:t=4.629, P<0.001)in winter had stronger effects on the emergency room visits for respiratory diseases in females than that in males, while the effects of NO₂(male:t=3.020, P=0.107;female:t=3.006, P=0.128), SO₂(male:t=4.101, P<0.001;female:t=3.820, P<0.001)and O₃8h(male:t=3.660, P=0.022;female:t=3.517, P=0.018)in winter showed an opposite trend.In age stratification, the increase in the daily average concentration of PM_2.5(0-14 years old:t=3.520, P=0.008), PM₁₀(0-14 years old:t=3.840, P<0.001), SO₂(0-14 years old:t=4.570, P<0.001), CO(0-14 years old:t=4.102, P=0.002)in winter would increase the emergency visits for respiratory diseases in the 0-14-year-old population.The daily average concentration of O₃8h(0-14 years old:t=4.210, P<0.001;15-64 years old:t=3.807, P=0.001)in summer only affected the visits of the 0-14-year-old and the 15-64-year-old populations, and the air pollutants had no significant effect on the visits of those≥65 years old.The double pollutant model analysis revealed that after introducing 5 other pollutants respectively, PM_2.5, PM₁₀, NO₂, SO₂ and O₃8h significantly increased the emergency room visits for respiratory diseases, and CO had a more obvious effect than that predicted with the single pollutant model. Conclusion The rises in the concentrations of six air pollutants in Lanzhou will increase the emergency room visits for respiratory diseases, and the patterns vary with different genders, ages and seasons.