奥运期间北京典型交通环境气态污染物特征及人体吸入剂量

Characteristics and intake dose of gaseous pollutants near a major Beijing road during the 29^(th) Olympic Games

为了评估2008年奥运会期间北京市机动车控制措施效果,对不同控制措施阶段北四环道路的气态污染物进行监测,并同步采集车流与气象信息.基于监测结果归纳气态污染物特征,分析控制措施的影响,并计算高峰小时与日间小时平均污染物人体吸入剂量.结果表明,控制措施全面实施期间(Ⅲ阶段)北四环路日间平均车流量下降约22%,其中轻型车流量降低约43%.与之相对应,北四环CO、NOx、NO2的浓度水平范围分别是0.10～3.94,0.002～0.139,0.002～0.099mg.m-3,较奥运前(2008年5月)监测浓度显著下降.其中,奥运赛事期间(Ⅲ-2阶段)CO、NOx、NO2平均浓度降幅最大,分别达到63%,71%和70%.奥运期间(Ⅲ阶段)CO与NOx的单人与总人群的高峰小时和日间平均小时吸入剂量较奥运前(2008年5月)均有显著下降,其中CO单人高峰小时与日间小时平均吸入剂量降幅分别是63%和81%;NOx单人高峰小时与日间小时平均吸入剂量降幅分别是58%和55%.区域总人群的吸入量也同比例下降.奥运期间严格的交通控制措施大幅削减了机动车污染物排放量,从而降低了道路交通环境机动车尾气污染引起的人体吸入剂量.

In order to evaluate the effects of control measures for vehicular pollution in Bejing taken during the 29th Olympic Games,a monitoring program was conducted on the North 4th-Ring Road in Beijing from May to August,2008.The program included the on-line measurement of concentrations of various gaseous pollutants,traffic flow and meteorological data.The impacts of by-stage vehicle control measures on the characteristics of gaseous pollutants are discussed;and the rush-hour and daytime average intakes for CO and NO2 are estimated.During phase Ⅲ,the total daytime traffic flow decreased by 22% （specifically,a significant reduction of 43% for light-duty vehicles） compared with that in May,which was attributed to the implementation of all vehicle control measures.At the same time,the hourly concentrations of CO,NOx,NO2 showed a significant decrease as well,varying over the range of 0.10～3.94 mg·m^-3,0.002～0.139 mg·m^-3,and 0.002～0.099 mg·m^-3,respectively.Especially during phase Ⅲ-2 （August 8～20）,when the Olympic Games was held in Beijing,the average concentrations of CO,NOx,and NO2 decreased by 63%,71% and 70%,separately,compared with those in May.As a result,the rush-hour and daytime average intakes for CO and NO2 decreased as well.During phase Ⅲ,the intakes for CO reduced 63% in rush-hour and 81% in daytime,while intakes for NOx reduced 58% in rush-hour and 55% in daytime.Stringent vehicle control measures implemented during Beijing Olympic Games enabled a large drop in vehicle emissions,significantly reducing the air pollution intake dose related to the traffic in Beijing.