Use of a mobile laboratory to evaluate changes in on-road air pollutants during the Beijing 2008 Summer Olympics

Abstract

Abstract. China implemented systematic air pollution control measures during the 2008 Beijing Summer Olympics and Paralympics to improve air quality. This study used a versatile mobile laboratory to conduct in situ monitoring of on-road air pollutants along Beijing's Fourth Ring Road on 31 selected days before, during, and after the Olympics air pollution control period. A suite of instruments with response times of less than 30 s was used to measure temporal and spatial variations in traffic-related air pollutants, including NO x , CO, PM 1.0 surface area (S(PM 1 )), black carbon (BC), and benzene, toluene, the sum of ethylbenzene, and m-, p-, and o-xylene (BTEX). During the Olympics (8-23 August, 2008), on-road air pollutant concentrations decreased significantly, by up to 54% for CO, 41% for NO x , 70% for SO 2 , 66% for BTEX, 12% for BC, and 18% for S PM 1 , compared with the pre-control period (before 20 July). Concentrations increased again after the control period ended (after 20 September), with average increases of 33% for CO, 42% for NO x , 60% for SO 2 , 40% for BTEX, 26% for BC, and 37% for S(PM 1 ), relative to the control period. Variations in pollutants concentrations were correlated with changes in traffic speed and the number and types of vehicles on the road. Throughout the measurement periods, the concentrations of NO x , CO, and BTEX varied markedly with the numbers of light-and medium-duty vehicles (LDVs and MDVs, respectively) on the road. Only after 8 August was a noticeable relationship found between BC and S(PM 1 ) and the number of heavy-duty vehicles (HDVs). Additionally, Correspondence to: T. Zhu (tzhu@pku.edu.cn) BC and S(PM 1 ) showed a strong correlation with SO 2 before the Olympics, indicating possible industrial sources from local emissions as well as regional transport activities in the Beijing area. Such factors were identified in measurements conducted on 6 August in an area southwest of Beijing. The ratio of benzene to toluene, a good indicator of traffic emissions, shifted suddenly from about 0.26 before the Olympics to approximately 0.48 after the Olympics began. This finding suggests that regulations on traffic volume and restrictions on the use of painting solvents were effective after the Olympics began. This study demonstrated the effectiveness of air pollution control measures and identified local and regional pollution sources within and surrounding the city of Beijing. The findings will be invaluable for emission inventory evaluations and model verifications.

Elucidating severe urban haze formation in China

“…On the contrary, we suggest that an effort to solely control emissions of primary particles is unlikely to be effective. Since the formation of severe urban and regional haze in China is ultimately attributable to its rapidly growing economy, fast urbanization, and large population, leading to lower standards but higher rates for air pollutant emissions (41), regulatory measures by the Chinese government to reduce the PM 2.5 levels and to minimize its regional to global impacts (1-5) may have profound consequences on China or even the world economy.…”

“…Hence, our measurements of gaseous species provide additional evidence on the contribution of urban-scale photochemical production to the measured dominant secondary aerosol constituents, confirming small contribution from primary emissions and regional transport of PM 2.5 . It should be pointed out that the pollution sources in Beijing are characteristic of the typical urban environments in China, i.e., with high emissions of VOCs and NO x from local transportation and SO 2 from regional industrial sources (26,27,41,42). Also, large contributions of VOCs and NO x from local traffic and SO 2 from regional industrial sources to secondary aerosol production have been previously identified in other global megacity areas (31).…”

On-Road Measurements of Ultrafine Particles and Associated Air Pollutants in a Densely Populated Area of Seoul, Korea

“…Roadside and vehicle tail pipe exhaust measurements must be linked to understand the spatial nature of UFPs, as well as differences in actual pollutant concentrations along roadways. Recent studies in various countries (China, Finland, Germany, Netherland, Switzerland, and United States) have developed mobile monitoring platforms using real-time instruments in attempts to estimate on-road air pollution concentrations together with spatial and temporal gradients of UFPs and related air pollutants (Bukowiecki et al, 2002a, b;Canagaratna et al, 2004;Kittelson et al, 2004a, b;Pirjola et al, 2004;Weijers et al, 2004;Schneider et al, 2008;Wang et al, 2009). Highways and arterial roads have been targeted for these measurements in both rural and urban areas.…”

Effectiveness evaluation of temporary emission control action in 2016 in winter in Shijiazhuang, China

“…For instance, the first attempt took place during the Beijing 2008 Olympic Games (Guo et al, 2013). Drastic control actions were executed to cut down the emissions of atmospheric pollutants from motor vehicles, industries, and building construction activities (UNEP, 2009;M. Wang et al, 2009;.…”