中国公共卫生

目的分析中国113个环境保护重点城市空气质量指数(AQI)的季节变化和区域分布特征。方法收集2014年中国113个环境保护重点城市AQI和首要污染物的日报监测数据,分析其时空变化特征。结果2014年中国研究城市的空气质量呈现"冬劣夏优"的特点。春季华北、东北和西北地区以PM10为首要空气污染物的城市比例分别为60.0%、81.8%和100.0%;夏季东北、华东、华南及西南地区以O3为首要空气污染物的城市比例分别为54.6%、68.8%、27.3%和40.0%;秋季以PM2.5为首要空气污染物的城市在华中地区和东北地区比例最高,分别为93.8%和81.8%,冬季以PM2.5为首要空气污染物的城市在东北地区和华东地区比例最高,分别为100.0%和96.9%;研究城市的区域性空气质量呈现以京津冀地区、河南省和山东省为中心向周边逐渐变好的特点。全年空气质量优劣排序为:华南>西南>东北>西北>华东>华中>华北,其优良率依次为83.74%、78.56%、68.24%、67.23%、65.06%、55.34%和52.47%。结论 2014年,PM2.5依然是中国主要的空气污染物,应重视防控各季节PM2.5污染,同时也应重视防控春季北方城市的PM10污染和夏季东北、华东、华南和西南地区城市的O3污染。

Objective To investigate spatial-temporal distribution characteristics of air quality indexes( AQI) in113 key cities for environmental protection in China. Methods We collected daily AQI data and the concentration data on primary air pollutants( including particulate matter less than 2. 5 microns in aerodynamic diameter [PM2. 5],particulate matter less than 10 microns in aerodynamic diameter [PM10],sulfur dioxide [SO2],nitrogen dioxide [NO2]carbon monoxide [CO],and ozone [O3]) from the 113 key environmental protection cities in China in 2014,and the spatiotemporal variation of air quality in the cities was analyzed. Results In 2014,the air quality in the cities was the worst in the winter but the best in the summer. In the spring,the proportions of the days with PM10 as a primary air pollutant were60. 0%,81. 8% and 100. 0% for the cities in North,Northeast,and Northwest China; in the summer,the proportions of the days with O3 as a primary air pollutant were 54. 6%,68. 8%,27. 3%,and 40. 0% for the cities in Northeast,East,South,and Southwest China; the proportions of the days with PM2. 5as a primary air pollutant were 93. 8% and 81. 8%for the cities in Central and Northeast China in the autumn and 100. 0% and 96. 9% for the cities in Northeast and East China in the winter. The regional air quality was gradually improved from the central regions( Beijing-Tianjin-Hebei province,Henan province,and Shandong province) to their surrounding cities. In 2014,the proportion of the days with good or excellent air quality( AQI ≤ 100) varied from 87. 74% to 52. 47% among all the cities and ranged in a decreased sequence for the cities in the South( 83. 74%),Southwest( 78. 56%),Northeast( 68. 24%),Northwest( 67. 23%),East( 65. 06%),Central( 55. 34%),and North China( 52. 47%). Conclusion In the year 2014,PM2. 5was still the primary air pollutant in China. Apart from controlling PM2. 5pollution,we should also pay close attention to the control of PM10 in the North cities in spring and O3 in the cities in the Northwest,East,South,and Southwest China in summer.