机动车禁行区街区尺度污染物时空分布——基于自行车车载走航

Spatiotemporal distribution of block scale air pollutants in motor-vehicle prohibited zone based on mobile observations of vehicle-mounted bicycles.

以武汉第七届世界军人运动会期间为研究时段,以机动车辆管控的东湖风景区为研究区域,开展基于自行车车载走航形式的大气污染物浓度实时观测,填补该区域空气质量监测数据空白,为管控措施的效果评估和街区尺度健康风险评估提供精细数据.结果表明,走航观测所测得的ρ(CO)、ρ(NO_(2))、ρ(PM2.5)和ρ(O_(3))平均值均高于监测站点,平均超过2.1倍.管控期机动车禁行区ρ(CO)、ρ(BC)、ρ(NO_(2))、ρ(PM_(2.5))和ρ(O_(3))的平均值分别为0.97mg/m^(3),5.6μg/m^(3),57.8μg/m^(3),76.3μg/m^(3)和208.3μg/m^(3),非禁行区分别为1.1mg/m^(3),4.7μg/m^(3),60.9μg/m^(3),72.2μg/m^(3)和197.7μg/m^(3).车群行驶缓慢的地方如路口和信号灯处容易出现高值,ρ(BC)、ρ(CO)、ρ(O_(3))和ρ(PM2.5)可分别高达20.1μg/m^(3),1.8mg/m^(3),282.9μg/m^(3)和106.3μg/m^(3).对应时间省控站点所测得的ρ(CO)、ρ(O_(3))和ρ(PM_(2.5))分别为0.73mg/m^(3),128.0μg/m^(3)和31.0μg/m^(3),明显低估街区尺度上人群污染物暴露浓度.基于TPRS法计算背景浓度,发现管控期CO、NO_(2)、PM1、PM2.5、PM10、O_(3)和BC的背景浓度占比分别为75.9%,63.2%,77.6%,77.5%,78.8%,80.7%和37.4%,在管控后均有所上升.

In order to fill the gap of air quality datasets and provide detailed information for assessing effects of pollution control measures and human health risks at a block scale,real-time observations with a vehicle-mounted bicycle navigation were conducted to monitor variations in the atmospheric pollutants during the 7th World Military Games Period at the East Lake Scenic Area of Wuhan where motor vehicle was prohibited.The results indicate that the measured values ofρ(CO),ρ(NO_(2)),ρ(PM_(2.5))andρ(O_(3))were averaged up to 2.1higher in the study area than in a nearby monitoring station.During the control period,the average concentrations ofρ(CO),ρ(BC),ρ(NO_(2)),ρ(PM_(2.5))andρ(O_(3))were 970,5.6,57.8,76.3 and 208.3μg/m^(3),respectively,in the vehicle prohibited zone,and 1100,4.7,60.9,72.2 and 197.7μg/m^(3),respectively,in the non-prohibited.The hotspots located at places of intersections and traffic lights,where theρ(BC),ρ(CO),ρ(O_(3))andρ(PM_(2.5))amounted up to 20.1,1800,282.9 and 106.3μg/m^(3),respectively;while the values ofρ(CO),ρ(O_(3))andρ(PM_(2.5))measured at a nearby monitoring station were 730,128.0 and 31.0μg/m^(3),respectively,which obviously were lower than(or underestimated)the concentrations of these pollutants actually exposed to people at the block scale.During the control period,the proportions of the background concentrations for CO,NO_(2),PM1,PM_(2.5),PM10,O_(3)and BC were 75.9%,63.2%,77.6%,77.5%,78.8%,80.7%and 37.4%,respectively,which all increased after the control.