2003-2010年西南地区省会城市空气污染指数的动态变化

Dynamic changes in air pollution index of provincial capital cities in southwestern China from 2003 to 2010

目的分析2003—2010年西南地区省会城市(成都、重庆、昆明、贵阳和拉萨)的空气污染指数(API)的动态变化。方法基于环境保护部网站数据中心和国家统计局发布的成都、重庆、昆明、贵阳和拉萨API值、空气质量等级、首要污染物及PM10、SO2、NO2年均浓度值,分析上述城市API年均值、季均值及主要污染物浓度。结果 2003—2010年上述5个城市的API年均值均呈下降趋势,重庆市API年均值由2003年的102逐年降至2010年的75,成都、昆明、贵阳和拉萨API年均值分别在89～77、71～58、69～63和59～44之间波动。研究年限内5个城市API季均值的变化特点均为"冬高夏低"。拉萨市的空气首要污染物仅为PM10,其他4个城市空气首要污染物均以PM10为主,其次为SO2。成都、重庆和贵阳PM10年均浓度均超过GB 3095—2012二级标准。成都、昆明和贵阳NO2年均浓度均呈缓慢上升趋势。结论 2003—2010年重庆市的空气质量明显好转,其他4个城市空气质量基本稳定。控制PM10排放是进一步改善5个城市空气质量的重要环节。

Objective Dynamic changes in air pollution index （API） of provincial capitals of southwestern China （including Chengdu, Chongqing, Kunming, Guiyang and Lhasa） from 2003 to 2010 were analyzed. Methods Data was collected from the Urban Ambient Air Quality Daily Report announced by the Ministry of Environmental Protection of the People＇s Republic of China and annual average concentration of inhalable particles, sulfur dioxide （SUE） and nitrogen dioxide （NO2） published by the National Bureau of Statistics of the People＇s Republic of China, from 2003 to 2010. Results The annual average APIs of the five cities showed a gradual decrease from 2003 to 2010. The annual average APIs of Chongqing decreased from 102 in 2003 to 75 in 2010, however, the fluctuation of annual average APIs for Chengdu, Kunming, Guiyang and Lhasa cities were 89 to 77, 71 to 58, 69 to 63 and 59 to 44, respectively. During the study period, the characteristics of average seasonal-change in APIs of the cities were the highest in winter and the lowest in summer. The primary and secondary air pollutants of the other four cites were inhalable particles and SO2, respectively, except for Lhasa city （only inhalable particles was detected）. The annual average concentrations of inhalable particles of Chengdu, Chongqing and Guiyang cities exceeded class Ⅱ of the national ambient air quality standard. With the exception of Chongqing and Lhasa cities, the increased trends of annual average NO2 concentrations were observed in the other three cities. Conclusion From 2003 to 2010, the air quality of Chongqing city was obviously improved, and change of air quality was not obvious in the other four cities. However, the further control of inhalable particles emission is important to improve air quality in these cities.