2014年APEC会议期间排放控制措施对大气污染物浓度的影响

Investigation of emission control measures' impacts on air pollutants in Beijing during the 2014 Asia-Pacific Economic Cooperation

目的评估排放控制措施对大气污染物浓度的影响。方法收集APEC会议前后(2014年10月20日-11月30日)北京市17个不同类型站点六种大气污染物(PM_(2.5)、PM_(10)、NO_2、CO、SO_2、O_3)浓度,运用秩和检验对不同类型站点,不同时期大气污染物浓度进行比较。采用线性混合效应模型,控制混杂因素,评估排放控制措施对大气污染物浓度的影响。结果 APEC会议期间PM_(2.5)、PM_(10)、NO_2、CO、SO_2的浓度相比于APEC会议前期分别下降了57.0%、50.6%、35.5%、31.8%、13.1%,但O_3浓度并没有减少。APEC会议期间PM_(2.5)、NO_2和CO的浓度在不同类型站点呈现出:交通站点>城市站点>郊区站点>对照站点的特点;而O_3在对照站点浓度最高,交通站点浓度最低。排放控制措施对控制大气污染物浓度非常有效,且其效力大于气象因素的影响。结论 2014年APEC会议期间排放控制措施对缓解北京空气污染和改善短期空气质量是有效的。

Objective The Asia-Pacific Economic Cooperation （APEC ） meeting was held between November 5 th to November 11th in Beijing, and comprehensive emission control measures were implemented. The impacts of these measures need to be evaluated. Methods An observational study on the concentrations of six major pollutants including PM2.5 , PM10 , NO 2 ,CO, S02 and 03 was carried out pre, during and post APEC. Concentrations data were collected from 17 monitoring sites in Beijing, including urban, suburban, transportation, and control sites. Comparisons of air pollutants ’ concentrations during different periods, in diverse types of monitoring sites and diurnal variations were performed by rank sum test. The influence of emission control measures were evaluated under controlling for confounding factors by the method of linear mixed effect models. Results Average daily concentrations of PM2.5 , PM10 , NO2 , CO, SO2were reduced by 57. 0% , 50. 6% ,35. 5% , 31. 8% and 13. 1 % respectively, compared with pre-APEC period. However, although the major precursor （ NO2 ） of 03 decreased significantly during-APEC, the levels of 03 were not reduced. During the APEC, the concentrations of PM2.5 , N02 and CO were the highest in transportation sites, followed by urban sites, suburban sites and control site. However, the concentration of O3 showed different characteristics compared with other pollutants, the highest concentrations of 03were in control site, the lowest were in transportation sites. The emission control measures were effective, and the strength were much greater than the influence of meteorological factors. Conclusion The emission control measures were effective in improving short term air quality in Beijing during 2014 APEC period, but more efforts and appropriate emission control measures is needed for long term and continuous air quality improvement. In addition, the influence pattern of secondary air pollutant needs to be further studied.