2003—2019年重点城市大气中SO_(2)污染趋势分析

Analysis of atmospheric SO_(2)pollution trend in key cities in China from 2003 to 2019

目的对4个直辖市、27个省会城市(31个城市)2003年以来大气中SO_(2)污染水平进行分析,提出可行性建议。方法收集国家统计局发布的2003—2019年31个城市SO_(2)年均质量浓度数据,计算SO_(2)年均污染水平下降幅度和年均下降率。SO_(2)污染水平的比较采用Kruskal-Wallis H进行检验,趋势检验采用Daniel趋势检验法。结果2003—2019年31个城市大气中SO_(2)的年均值浓度为(38±24)μg/m^(3),范围为2~152μg/m^(3),总体呈下降趋势(rs=-0.985,P<0.05)。华北、西北、东北和华中污染较重,华东、华南和西南相对较轻。自2003年起,31个城市大气中SO_(2)的年均值水平均达到《环境空气质量标准》的二级标准限值要求(<60μg/m^(3)),自2017年起达到一级标准限值要求(<20μg/m^(3)),自2015年起显著下降,差异有统计学意义(P<0.05)。29个城市(太原和乌鲁木齐除外)SO_(2)平均污染水平达到GB 3095—2012二级标准限值要求,其中4个城市(拉萨、海口、福州、合肥)平均污染水平达到一级标准限值要求;30个城市(拉萨除外)SO_(2)年均质量浓度均呈不同程度的下降,降幅为8%~94%(年均下降率为1%~16%),降幅最大的前5个城市分别为重庆、北京、乌鲁木齐、长沙和石家庄,降幅在90%以上(年均下降率为13%~16%),25个城市(除拉萨、沈阳、西宁、合肥、长春、银川除外)年度下降趋势比较,差异有统计学意义(P<0.05)。结论2003—2019年中国大气SO_(2)污染防治工作取得阶段成果,今后应继续加强监管,采取措施减少污染物排放。

Objective To analyze the levels of Sulfur dioxide(SO_(2))pollution in the atmosphere of 4 municipality and 27 provincial capital cities(31 cities)in China since 2003,and to put forward feasible suggestions.Methods The annual average mass concentration data of SO_(2)in 31 cities from 2003 to 2019 were derived from the official website of the National Bureau of Statistics,and the annual average reduction rate and reduction range of SO_(2)pollution levels were calculated.The compare of SO_(2)pollution levels among different groups was tested by Kruskal-Wallis H test.The trend test was conducted by Daniel trend test method.Results From 2003 to 2019,annual average concentration of SO_(2)in the atmosphere of 31 cities was(38±24)μg/m^(3),ranging from 2 to 152μg/m^(3),showing an downward trend overall(r_(s)=-0.985,P<0.05).The pollution of North,Northwest,Northeast and Central China was more serious,while it was relatively lighter in East,South and Southwest China.Since 2003,the annual average pollution level of SO_(2)in atmosphere of 31 cities had met the second-class standard limit requirements of GB 3095—2012(<60μg/m^(3)),and since 2017,it had met the first-class standard limit requirements(<20μg/m^(3)).From 2015,it was decreased significantly,and the difference was statistically significant(P<0.05).The average pollution levels of SO_(2)in 29 cities(except Taiyuan and Urumqi)had met the second-class standard limit requirements of GB 3095—2012.Among them,the average pollution levels in 4 cities(Lhasa,Haikou,Fuzhou,Hefei)had met the first-class standard limit requirements.The annual average mass concentration of SO_(2)in 30 cities(except Lhasa)had varying degrees of decline,with a reduction range from 8%to 94%(annual average reduction rate was from 1%to 16%).The top 5 cities with the largest reduction were Chongqing,Beijing,Urumqi,Changsha and Shijiazhuang,with a reduction of more than 90%(annual average reduction rate was from 13%to 16%).The annual downward trends of 25 cities(except Lhasa,Shenyang,Xining,Hefei,Changchun and Yinchuan)were compared,and the difference was statistically significant(P<0.05).Conclusion The prevention and control of atmospheric SO_(2)pollution in China from 2003 to 2019 has achieved phased results.In the future,supervision should be strengthened and measures should be taken to reduce pollutant emissions.