Evaluating the air quality impacts of the 2008 Beijing Olympic Games: On-road emission factors and black carbon profiles

Wang, Xing; Westerdahl, Dane; Chen, Lung Chi; Wu, Ye; Hao, Jiming; Pan, Xiaochuan; Guo, Xinbiao; Zhang, K. Max

doi:10.1016/j.atmosenv.2009.06.054

Cited by 128 publications

(76 citation statements)

References 28 publications

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“…Seventy percent of government cars as well as 50% of the private cars were banned from the road, reducing ∼2 million on-road automobiles each day during the BOG. 21,22 Since PCDD/Fs can be emitted from vehicle exhaust, 33 the decreased vehicle use was expected to result in the reduction of PCDD/Fs emissions to the Figure 2 shows the variation of atmospheric PCDD/Fs at the three urban sites before, during, and after the Olympic Games, which fitted with parabolic regressions (p < 0.05) as a function of time. For all of the three urban sites, ∑PCDD/Fs during the BOG showed significantly lower concentrations compared to July 2008, before the Olympic event began (Tukey's post hoc test, p < 0.05), with an average reduction of 29%.…”

Section: ' Introductionmentioning

confidence: 99%

Reduction of Atmospheric Polychlorinated Dibenzo-p-Dioxins and Dibenzofurans (PCDD/Fs) during the 2008 Beijing Olympic Games

Wang

et al. 2011

Environ. Sci. Technol.

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A total of 120 air samples were collected at three urban and one rural location in Beijing, China in the summers of 2007−2010, and before, during, and after the Beijing 2008 Olympic Games (BOG), in order to assess the effectiveness of long-term and short-term emission-control measures in reducing polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the atmosphere. During the BOG (August, 2008), the PCDD/Fs concentrations decreased to an average value of 1150 fg m−3 (63 fg I-TEQ m−3), which was reduced by approximately 70% from the average in 2007 and by 29% from that in July 2008, before the Olympic event began. Although 2009−2010 levels of PCDD/Fs were significantly higher than 2008, the overall temporal trend was decreasing for summer months during the sampling campaign period. The apparent half-lives of atmospheric PCDD/Fs were estimated to be 3.2−5.8 years by statistically regressing the logarithm PCDD/Fs concentrations versus the number of years passed since 2006. The air concentrations of total suspended particulates (TSP) during the BOG ranged between 135 and 183 μg m−3, showing a 52% reduction from 2007 and 26% decrease from those prior to the Olympic event. No significant relationships were found between meteorological parameters (temperature, humidity, and wind speed) and PCDD/Fs or TSP during the BOG, whereas the PCDD/Fs concentrations were significantly dependent on the air quality (p < 0.05, positive against TSP and negative against visibility). This work is one of few temporal trend studies of atmospheric PCDD/Fs in mainland China, and provides unique insight into the effects of large-scale control measures in improving air quality and reducing one of the most ubiquitous and toxic organic pollutants in the environment.

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Section: ' Introductionmentioning

confidence: 99%

Reduction of Atmospheric Polychlorinated Dibenzo-p-Dioxins and Dibenzofurans (PCDD/Fs) during the 2008 Beijing Olympic Games

Wang

et al. 2011

Environ. Sci. Technol.

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“…Vehicle emission factor estimation can be conducted using a number of methods, including chassis dynamometer experiments, tunnel studies, and remote sensing, but mobile monitoring methods are often selected because they enable researchers to characterize in-use emissions of individual vehicles under a variety of operating conditions (Park et al, 2011;Wang et al, 2011Wang et al, , 2012Westerdahl et al, 2009;Wang et al, 2009).…”

Section: Recreational Vehiclementioning

confidence: 99%

Mobile air monitoring data-processing strategies and effects on spatial air pollution trends

et al. 2014

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Abstract. The collection of real-time air quality measurements while in motion (i.e., mobile monitoring) is currently conducted worldwide to evaluate in situ emissions, local air quality trends, and air pollutant exposure. This measurement strategy pushes the limits of traditional data analysis with complex second-by-second multipollutant data varying as a function of time and location. Data reduction and filtering techniques are often applied to deduce trends, such as pollutant spatial gradients downwind of a highway. However, rarely do mobile monitoring studies report the sensitivity of their results to the chosen data-processing approaches. The study being reported here utilized 40 h (> 140 000 observations) of mobile monitoring data collected on a roadway network in central North Carolina to explore common data-processing strategies including local emission plume detection, background estimation, and averaging techniques for spatial trend analyses. One-second time resolution measurements of ultrafine particles (UFPs), black carbon (BC), particulate matter (PM), carbon monoxide (CO), and nitrogen dioxide (NO 2 ) were collected on 12 unique driving routes that were each sampled repeatedly. The route with the highest number of repetitions was used to compare local exhaust plume detection and averaging methods. Analyses demonstrate that the multiple local exhaust plume detection strategies reported produce generally similar results and that utilizing a median of measurements taken within a specified route segment (as opposed to a mean) may be sufficient to avoid bias in near-source spatial trends.A time-series-based method of estimating background concentrations was shown to produce similar but slightly lower estimates than a location-based method. For the complete data set the estimated contributions of the background to the mean pollutant concentrations were as follows: BC (15 %), UFPs (26 %), CO (41 %), PM 2.5−10 (45 %), NO 2 (57 %), PM 10 (60 %), PM 2.5 (68 %). Lastly, while temporal smoothing (e.g., 5 s averages) results in weak pair-wise correlation and the blurring of spatial trends, spatial averaging (e.g., 10 m) is demonstrated to increase correlation and refine spatial trends.

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“…They have been used extensively to monitor environmental BC levels because of their ease of operation, and favorable time resolution (Watson et al, 2005;Park et al, 2006;Chow et al, 2009). Such online measurement instruments are critical to research studies that seek to characterize short-term and/or long-term variability in BC levels, such as by measuring source emissions that change rapidly, comparing time-varying outdoor/indoor air pollution levels, or observing dynamic trends in ambient air quality (Badarinath and Latha, 2006;Fruin et al, 2008;Rodríguez et al, 2008;Sandradewi et al, 2008;Dutkiewicz et al, 2009;Wang et al, 2009;Snyder et al, 2010;Boogaard et al, 2011;Hyvärinen et al, 2011;Reche et al, 2011;Viana et al, 2011;Wang et al, 2011;Reddy et al, 2012;Wang et al, 2012;Cheng et al, 2013). They also could be used to evaluate the light absorption coefficient of aerosol by measuring the attenuation of light through deposited aerosol (Lavanchy et al, 1999;Weingartner et al, 2003;Arnott et al, 2005;Fialho et al, 2005;Schmid et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

Real-Time Performance of the microAeth® AE51 and the Effects of Aerosol Loading on Its Measurement Results at a Traffic Site

Chen

Lin

2013

Aerosol Air Qual. Res.

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The new portable microAeth ® AE51 (AE51) is very useful for assessing occupational and environmental exposure to black carbon (BC) aerosols in epidemiological research. However, information about the performance of AE51 is limited. This study compares AE51 with the widely used, rack-mounted Aethalometer ® AE31 (AE31) by evaluating the real-time performance of these two instruments, as carried out at a traffic site. Additionally, an optimized noise-reduction averaging (ONA) algorithm is adopted to eliminate the negative values in the BC data sets. Negative BC levels may be present using AE51 at low actual BC levels or at a high time-resolution. The negative values can be eliminated very effectively by the ONA method. The time-variation of the 5 min BC levels measured using AE51 is highly consistent with that measured using AE31. Loading effects on the measured BC levels are observed during the sampling period. Additionally, the correcting factor, k, is evaluated, in which the correcting factors are 0.0033 and 0.0039 for AE31 and AE51, respectively, when used to monitor the BC levels at this traffic site. The analytical results indicate that the BC levels are underestimated by up to 15% when the ATN-ATN 0 increases to ~40. The measurement results also reveal that the BC levels measured by AE51 are approximately 14% higher than those measured using AE31. These results may be due to the different aerosol deposition velocities and mass attenuation cross-section parameters (σ ATN ) of the two instruments.

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Evaluating the air quality impacts of the 2008 Beijing Olympic Games: On-road emission factors and black carbon profiles

Cited by 128 publications

References 28 publications

Reduction of Atmospheric Polychlorinated Dibenzo-p-Dioxins and Dibenzofurans (PCDD/Fs) during the 2008 Beijing Olympic Games

Reduction of Atmospheric Polychlorinated Dibenzo-p-Dioxins and Dibenzofurans (PCDD/Fs) during the 2008 Beijing Olympic Games

Mobile air monitoring data-processing strategies and effects on spatial air pollution trends

Real-Time Performance of the microAeth® AE51 and the Effects of Aerosol Loading on Its Measurement Results at a Traffic Site

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