中文摘要：

利用城市生态系统研究站对北京市奥运前后（2008年6~9月）大气中细颗粒物（PM2.5）进行连续监测,获得不同阶段PM 2.5日平均浓度的动态特征,分析气象因素、人为控制管理措施对颗粒物浓度的影响. 结果表明,近北五环的生态中心站点（RCEES）颗粒物日均浓度平均值为0.067 mg·m-3,奥运期间的颗粒物浓度（0.060 mg·m-3）比奥运前期（0.081 mg·m-3）减少了约26%. 而位于南二环市中心的教学植物园站点（JX）颗粒物浓度平均含量为0.078 mg·m-3. JX站点奥运期间的颗粒物浓度（0.069 mg·m-3）比奥运前期（0.095 mg·m-3）减少了约27%. 各个阶段PM2.5的日变化都基本呈现双峰态势. 第一个峰值出现在08：00~10：00左右,RCEES站点颗粒物浓度为0.068 mg·m-3,JX站点浓度值为0.089 mg·m-3; 另一个峰值出现在晚20：00~22：00左右,RCEES和JX站点颗粒物浓度为0.079 mg·m-3和0.083 mg·m-3,这主要与上班交通高峰导致的尾气排放污染和道路扬尘污染等有关. 研究气象参数发现奥运期间与奥运前期气象条件无显著差异,属于高温高湿风力不大的典型北京夏季天气条件. 奥运期间颗粒物浓度与温度呈显著正相关（P〈0.01）,而与风速、相对湿度及降水相关性不显著（P〉0.05）. 而连续多年大气污染综合治理措施和奥运空气质量保障措施的实施,产生了显著环境效益. 在自然因素相差不大的条件下,人为控制因素对奥运期间颗粒物的下降起到主导作用.

英文摘要：

Two city ecosystem research stations were selected for continuous monitoring of atmospheric fine particulate matter （PM2.5） concentration from June to September 2008, when the Beijing Olympic Games was held. The relationship between meteorological factors, artificial control management measures and PM2.5 dynamic characteristics were analyzed. The results showed that the daily average concentration of PM2.5 at RCEES Station, which is near the 5th North Ring, was 0.067 mg·m-3 during the study period, and the particle concentration during the Olympic Games was 0.060 mg·m-3, which was decreased by about 26% compared with the content before the Olympic Games （0.081 mg·m-3）. As for JX Station located in the 2th South Ring, its daily average concentration of PM2.5 was 0.078 mg·m-3. Similar to RCEES Station, PM2.5 average content during the Olympic Games （0.069 mg·m-3） was 27% lower compared with the content before the Olympic Games （0.095 mg·m-3）.Two peaks could be found when daily distribution of PM2.5 was displayed,one appeared between 08：00 and 10：00 （the average content for RCEES and JX were 0.068 and 0.089 mg·m-3, respectively）, and the other appeared at 20：00-22：00, which could be attributed to traffic emission and road dust pollution, especially the emission from the growing number of cars in rush hours. Meteorological condition during the whole period was typical in summer in Beijing with both high temperature and humidity. Correlation analysis revealed that the concentrations of PM2.5 had a positive correlation with the air temperature （P〈0.01）, while it had no significant relationship with wind speed, relative humidity or precipitation （P〉0.05）. Our monitoring results suggested that the artificial air pollution control strategies were effective measures for air pollution control during 2008 Beijing Olympic Game.