Site In Beijing Research Articles

Effects of Size-Fractionated Particulate Matter on Cellular Oxidant Radical Generation in Human Bronchial Epithelial BEAS-2B Cells.

The aim of the present study was to investigate the effects of size-fractionated (i.e., <1; 1–2.5, and 2.5–10 µm in an aerodynamic diameter) ambient particulate matter (PM) on reactive oxygen species (ROS) activity and cell viability in human bronchial epithelial cells (BEAS-2B). The PM samples were collected from an urban site (uPM) in Beijing and a steel factory site (sPM) in Anshan, China, from March 2013 to December 2014. Metal elements, organic and elemental carbon, and water-soluble inorganic ions in the uPM and sPM were analyzed. The cell viability and ROS generation in PM-exposed BEAS-2B cells were measured by MTS and DCFH-DA. The results showed that both uPM and sPM caused a decrease in the cell viability and an increase in ROS generation. The level of ROS measured in sPM1.0 was approximately triple that in uPM1.0. The results of correlation analysis showed that the ROS activity and cytotoxicity were related to different PM composition. Moreover, deferoxamine (DFO) significantly prevented the increase of ROS generation and the decrease of cell viability. Taken together, our results suggest that the metals absorbed on PM induced oxidant radical generation in BEAS-2B cells that could lead to impairment of pulmonary function.

Intensification of aerosol pollution associated with its feedback with surface solar radiation and winds in Beijing

AbstractBeijing has been experiencing serious air pollution in recent years, resulting in serious impacts on the local environment and climate and on human health. In addition to individual pollution sources and weather systems, feedback between aerosols and downwelling solar radiation (DSR) and between aerosols and winds also contribute to heavy aerosol pollution. By using atmospheric visibility (VIS) to represent the relative amount of aerosol pollution during a 5 week observation around the Asia‐Pacific Economic Cooperation (APEC) period (22 October to 25 November 2014) over a site in south Beijing, China, we show clear positive relationships between DSR and VIS and between winds and VIS. The sensitivities of daily DSR and surface winds to VIS are approximately 15.42 W/m2/km and 0.068 m/s/km, respectively. The strengthening contributions to atmospheric visibility by surface DSR‐VIS interactions and between surface wind‐aerosol interactions are estimated at approximately 15% and 12%, respectively, in south Beijing around the APEC period.

Analysis of chemical characteristics of PM2.5 in Beijing over a 1-year period

Beijing is one of the largest and most densely populated cities in China. PM2.5 (fine particulates with aerodynamic diameters less than 2.5 μm) pollution has been a serious problem in Beijing in recent years. To study the temporal and spatial variations in the chemical components of PM2.5 and to discuss the formation mechanisms of secondary particles, SO2, NO2, PM2.5, and chemical components of PM2.5 were measured at four sites in Beijing, Dingling (DL), Chegongzhuang (CG), Fangshan (FS), and Yufa (YF), over four seasons from 2012 to 2013. Fifteen chemical components, including organic carbon (OC), elemental carbon (EC), K+, NH4 +, NO3 −, SO4 2−, Cl−, Al, Ca, Fe, Mg, Na, Pb, Si, and Zn, were selected for analysis. Overall, OC, SO4 2−, NO3 −, and NH4 + were dominant among 15 components, the annual average concentrations of which were 22.62 ± 21.86, 19.39 ± 21.06, 18.89 ± 19.82, and 13.20 ± 12.80 μg·m−3, respectively. Compared with previous studies, the concentrations of NH4 + were significantly higher in this study. In winter, the average concentrations of OC and EC were, respectively, 3 and 2.5 times higher than in summer, a result of coal combustion during winter. The average OC/EC ratios over the four sites were 4.9, 7.0, 8.1, and 8.4 in spring, summer, autumn, and winter, respectively. The annual average [NO3 −]/[SO4 2−] ratios in DL, CG, FS, and YF were 1.01, 1.25, 1.08, and 1.12, respectively, which were significantly higher than previous studies in Beijing, indicating that the contribution ratio of mobile source increased in recent years in Beijing. Analysis of correlations between temperature and relative humidity and between SOR ([SO4 2−]/([SO4 2−] + [SO2])) and NOR ([NO3 −]/([NO3 −] + [NO2])) indicated that gas-phase oxidation reactions were the major formation mechanism of SO4 2− in spring and summer in urban Beijing, whereas slow gas-phase oxidation reactions and heterogeneous reactions both occurred in autumn and winter. NO3 − was mainly formed through year-round heterogeneous reactions in urban Beijing.

Seasonal variations and source estimation of saccharides in atmospheric particulate matter in Beijing, China

Saccharides are important constituents of atmospheric particulate matter (PM). In order to better understand the sources and seasonal variations of saccharides in aerosols in Beijing, China, saccharide composition was measured in ambient PM samples collected at an urban site in Beijing. The highest concentrations of total saccharides in Beijing were observed in autumn, while an episode with abnormal high total saccharide levels was observed from 15 to 23 June, 2011, due to extensive agricultural residue burning in northern China during the wheat harvest season. Compared to the other two categories of saccharides, sugars and sugar alcohols, anhydrosugars were the predominant saccharide group, indicating that biomass burning contributions to Beijing urban aerosol were significant. Ambient sugar and sugar alcohol levels in summer and autumn were higher than those in spring and winter, while they were more abundant in PM2.5 during winter time. Levoglucosan was the most abundant saccharide compound in both PM2.5 and PM10, the annual contributions of which to total measured saccharides in PM2.5 and PM10 were 61.5% and 54.1%, respectively. To further investigate the sources of the saccharides in ambient aerosols in Beijing, the PM10 datasets were subjected to positive matrix factorization (PMF) analysis. Based on the objective function to be minimized and the interpretable factors identified by PMF, six factors appeared to be optimal as to the probable origin of saccharides in the atmosphere in Beijing, including biomass burning, soil or dust, isoprene SOA and the direct release of airborne fungal spores and pollen.

Gas and particle size distributions of polychlorinated naphthalenes in the atmosphere of Beijing, China

Polychlorinated naphthalenes (PCNs) were listed as persistent organic pollutants in the Stockholm Convention in 2015. Despite numerous studies on PCNs, little is known about their occurrence in atmospheric particulate matter of different sizes. In this study, 49 PCN congeners were investigated for their concentrations and size-specific distributions in an urban atmosphere, and preliminary exposure assessments were conducted. Ambient air samples were collected using a high-volume cascade impactor for division into a gas fraction and four particle size fractions. Samples were collected from October 2013 to June 2014 at an urban site in Beijing, China. The concentration range for PCNs in the atmosphere (gas + particle fractions) was 6.77–25.90 pg/m3 (average 16.28 pg/m3). The particle-bound concentration range was 0.17–2.78 pg/m3 (average 1.73 pg/m3). Therefore, PCNs were mainly found in the gas phase. The concentrations of PCNs in a fraction increased as the particle size decreased (dae > 10 μm, 10 μm ≥ dae > 2.5 μm, 2.5 μm ≥ dae > 1.0 μm and dae ≤ 1.0 μm). Consequently, PCNs were ubiquitous in inhalable fine particles, and the ΣPCNs associated with PM1.0 and PM2.5 reached 68.4% and 84.3%, respectively. Tetra-CNs and penta-CNs (the lower chlorinated homologues) predominated in the atmosphere. The homologue profiles in different size particles were almost similar, but the particulate profiles were different from those in the gas phase. Among the individual PCNs identified, CN38/40, CN52/60 and CN75 were the dominant compounds in the atmosphere. CN66/67 and CN73 collectively accounted for most of the total dioxin-like TEQ concentrations of the PCNs. Exposure to toxic compounds, such as PCNs present in PM1.0 or PM2.5, may affect human health. This work presents the first data on size-specific distributions of PCNs in the atmosphere.

Residents’ recreational and social use of and perspectives on a World Heritage Site: Temple of Heaven, Beijing, China

Many heritage sites are shared by tourists and local residents. Possessing more familiarity and often a deeper understanding of local heritage meanings and values, residents are often considered to be more worthy users of the heritage resources. However, the recreational use of heritage resources by local residents, who are often portrayed and examined as service providers and impact receivers, is often neglected at heritage sites. This research identifies the use patterns, motivations, perceptions and experiences of local residents at Temple of Heaven World Heritage Site in Beijing, China. Research findings enhance understanding of the recreational use of residents and their perspectives on the heritage sites. Practical implications are generated to inform future planning and management decisions at heritage sites shared by local users and tourists.

北京市PM2.5化学组分特征

PDF HTML阅读 XML下载 导出引用 引用提醒 北京市PM2.5化学组分特征 DOI: 10.5846/stxb201410142021 作者: 作者单位: 北京市环境保护监测中心;中国环境科学研究院环境基准与风险评估国家重点实验室,北京市环境保护监测中心,北京市环境保护监测中心,北京市环境保护监测中心,北京市环境保护监测中心,北京市环境保护监测中心,北京市环境保护监测中心,中国环境科学研究院环境基准与风险评估国家重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 环保公益性行业科研专项(201409005); 国家科技支撑计划课题(2014BAC23B03) Chemical characteristics of PM2.5 in Beijing Author: Affiliation: Beijing Municipal Environmental Monitoring Center;China;;State Key Lab of Environmental Criteria and Risk Assessment,Chinese Research Academy of Environmental Sciences;China,Beijing Municipal Environmental Monitoring Center,Beijing Municipal Environmental Monitoring Center,Beijing Municipal Environmental Monitoring Center,Beijing Municipal Environmental Monitoring Center,Beijing Municipal Environmental Monitoring Center,Beijing Municipal Environmental Monitoring Center,State Key Lab of Environmental Criteria and Risk Assessment,Chinese Research Academy of Environmental Sciences Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:对2012年8月至2013年7月期间北京市定陵、车公庄、房山和榆垡4个站点的15种PM2.5化学组分进行分析,探讨各组分的时空分布特征以及有机碳(OC)、元素碳(EC)的污染特征。结果表明,4个站点PM2.5组分中OC、SO42-、NO3-和NH4+的含量较高,年均浓度分别为(22.62±21.86)、(19.39±21.06)、(18.89±19.82)、(13.20±12.80) μg/m3。各组分浓度在时间分布上多为冬季最高,夏季最低;在空间分布上多为南部高,北部低;另外NH4+浓度水平明显高于早年间的监测结果。受燃煤的影响,冬季OC和EC平均浓度分别为夏季浓度的3倍和2.5倍。春、夏、秋、冬季4个站点平均OC/EC比值分别为4.9、7.0、8.1和8.4,表明北京市全年均存在较严重的SOC污染。采用OC/EC比值法估算得出全年定陵、车公庄、房山和榆垡站二次有机碳(SOC)占OC的比例分别为57.7%、60.0%、45.6%和57.6%。定陵、车公庄、房山和榆垡站年均[NO3-]/[SO42-]比值分别为1.01、1.25、1.08和1.12,表明目前北京市排放源表现出固定源和移动源并重的特征。 Abstract:The chemical compositions of samples of particulate matter up to 2.5 μm in size (PM2.5)collected from Dingling, Chegongzhuang, Fangshan, and Yufa sites in Beijing, China from August 2012 to July 2013 were analyzed to determine the spatiotemporal characteristics of 15 chemical components, including nitrogen- and sulfur-containing air pollutants and organic carbon (OC) and elemental carbon (EC). The concentrations of OC, SO42-, NO3-, and NH4+ were the highest among the 15 chemical components analyzed, and the annual mean concentrations were (22.62±21.86), (19.39±21.06), (18.89±19.82), and (13.20±12.80) μg/m3, respectively. In general, concentrations of the 15 chemical components were highest in winter and lowest in summer, and concentrations were higher in southern areas and lower in northern areas.Concentrationsof NH4+observed in this study were significantly higher than those reported in previous monitoring studies. Concentrations of OC and EC in winter were 3-times and 2.5-times higher, respectively, than the corresponding levels in summer, which was attributed to higher rates of coal consumption in winter. The average ratios of OC/EC in spring, summer, autumn, and winter were 4.9, 7.0, 8.1, and 8.4, respectively, which are indicative of serious pollution levels in Beijing throughout the year. The proportions of secondary organic carbon to OC at the Dingling, Chegongzhuang, Fangshan, and Yufa sites were 57.7%, 60.0%, 45.6%, and 57.6%, respectively, which were calculated based on the OC/EC ratio. The annual ratios of [NO3-]/[SO42-] at the Dingling, Chegongzhuang, Fangshan, and Yufa sites were 1.01, 1.25, 1.08, and 1.12, respectively.These data imply that both stationary and mobile sources are important contributors to the poor air quality in Beijing. 参考文献 相似文献 引证文献

Distinct potential aerosol masses under different scenarios of transport at a suburban site of Beijing

In order to evaluate the secondary aerosol formation potential at a suburban site of Beijing, in situ perturbation experiments in a potential aerosol mass (PAM) reactor were carried out in the winter of 2014. The variations of secondary aerosol formation as a function of time, OH exposure, and the concentrations of gas phase pollutants and particles were reported in this study. Two periods with distinct secondary aerosol formation potentials, marked as Period I and Period II, were identified during the observation. In Period I, the secondary aerosol formation potential was high, and correlated well to the air pollutants, i.e., SO2, NO2, and CO. The maximal secondary aerosol formation was observed with an aging time equivalent to about 3days of atmospheric oxidation. In period II, the secondary aerosol formation potential was low, with no obvious correlation with the air pollutants. Meanwhile, the aerosol mass decreased, instead of showing a peak, with increasing aging time. Backward trajectory analysis during the two periods confirmed that the air mass in Period I was mainly from local sources, while it was attributed mostly to long distance transport in Period II. The air lost its reactivity during the long transport and the particles became highly aged, resulting in a low secondary aerosol formation potential. Our experimental results indicated that the in situ measurement of the secondary aerosol formation potential could provide important information for evaluating the contributions of local emission and long distance transport to the aerosol pollution.

Heavy haze episodes in Beijing during January 2013: Inorganic ion chemistry and source analysis using highly time-resolved measurements from an urban site

The heavy air pollution that occurred in Beijing in January of 2013 attracted intense attention around the world. During this period, we conducted highly time-resolved measurements of inorganic ions associated with PM2.5 at an urban site of Beijing, and investigated ion chemistry and potential sources. Hourly concentrations of Cl−, NO3−, SO42−, Na+, NH4+, K+, Mg2+, and Ca2+ were measured. Peak concentrations of SO42− and NO3− were observed on the 10th–15th, 21st–24th, and the 26th–30th during this monitoring campaign. The percentages of SO42− and NH4+ in total ion concentration increased with the enhancement of PM2.5 concentrations, indicating that high concentrations of SO42− and NH4+ may play important roles in the formation of haze episodes. The ratio of [NO3−]/[SO42−] was calculated, revealing that the sources of SO42− would contribute more to the formation of PM2.5 than mobile sources. Diurnal variations of SO42−, NO3−, NH4+ (SNA) exhibited a similar pattern, with high concentrations at night and low levels during the day, revealing that meteorological conditions, such as mixing layer height, relative humidity, were likely to be responsible for high levels of SNA at night. The roles of meteorological conditions were further discussed in the formation of secondary inorganic ions. Relative humidity and temperature played key roles and exhibited positive correlations with secondary inorganic ions. An aerosol inorganics simulation model showed that SNA existed mainly in the aqueous phase during the sampling period. Furthermore, potential sources were identified by applying positive matrix factorization model. Secondary nitrate, secondary sulfate, coal combustion and biomass burning, as well as fugitive dust, were considered to be major contributors to total ions.

Anthropogenic and biogenic organic compounds in summertime fine aerosols (PM2.5) in Beijing, China

Abstract Ambient fine aerosol samples (PM2.5) were collected at an urban site (PKU) in Beijing and its upwind suburban site (Yufa) during the CAREBEIJING-2007 field campaign. Organic molecular compositions of the PM2.5 samples were studied for seven organic compound classes (sugars, lignin/resin acids, hydroxy-/polyacids, aromatic acids, biogenic SOA tracers, fatty acids and phthalates) using capillary GC/MS to better understand the characteristics and sources of organic aerosol pollution in Beijing. More than 60 individual organic species were detected in PM2.5 and were grouped into different compound classes based on their functional groups. Concentrations of total quantified organics at Yufa (469–1410 ng m−3, average 1050 ng m−3) were slightly higher than those at PKU (523–1390 ng m−3, 900 ng m−3). At both sites, phthalates were found as the most abundant compound class. Using a tracer-based method, the contributions of the biogenic secondary organic carbon (SOC) to organic carbon (OC) were 3.1% at PKU and 5.5% at Yufa, among which isoprene-SOC was the dominant contributor. In addition, most of the measured organic compounds were higher at Yufa than those at PKU, indicating a more serious pollution in its upwind region than in urban Beijing.

Pass the Flame: Tentative Programs of Cultural Heritage Education Among Teenagers in Yuanmingyuan Site

Abstract. Yuanmingyuan is a very important cultural heritage site in Beijing, China. In order to improve the conservation of Yuanmingyuan Site and increase communication between the cultural heritage site and the public, especially the teenagers, our institute initiated a serial of education programs in the past two years, cooperating with local schools, including courses on the base of school curriculums, independent cultural heritage summer camp, and special sessions in international cultural heritage symposium. All these programs have received positive feedback and shown promising future.

Aerosol Optical and Microphysical Properties of Four Typical Sites of SONET in China Based on Remote Sensing Measurements

The current understanding of columnar aerosol optical and microphysical properties of different regions and seasons in China is insufficient due to the lack of measurements. Aiming to improve descriptions of aerosol models over China, this paper presents a systematic aerosol characterization of different sites based on a newly developed remote sensing network for aerosol observation, the Sun-sky radiometer Observation NETwork (SONET). One year of ground-based solar and sky radiation measurements of four typical sites of SONET (Beijing–urban-industrial site, Zhangye—rural site, Minqin—desert site, Zhoushan–oceanic site) are used to retrieve aerosol properties using similar inversion algorithms with AErosol RObotic NETwork (AERONET), including aerosol optical depth, Ångström exponent, volume size distribution, complex refractive index, single scattering albedo, and percentage of spherical particles. The retrieved properties among sites and seasons are found to be different in terms of magnitude, spectral dependence, and partition of fine and coarse mode, which can be primarily explained by different aerosol composition and mixing states that closely relate to the local climate, the natural environment, and most importantly, the ubiquitous anthropogenic impacts. For example, large dust particles greatly contribute to the low fine mode fraction in both volume concentration and optical depth for the Minqin site through the entire year, while abundant small particles that mainly come from emission sources dominate the size distribution and light extinction of aerosol in the summer at the Beijing site. The results also show general agreements with other studies on the aerosol properties at each site, however, some unique features are still noticeable, especially at the desert site and oceanic site (e.g., the unusually strong aerosol absorptivity indicated by the large imaginary refractive index and low single scattering albedo at the Minqin and Zhoushan sites), which can be partly attributed to the existence of absorbing particles coming from anthropogenic sources.

Analysis of organic and elemental carbon in heating and non-heating periods in four locations of Beijing

The concentrations of elemental carbon (EC) and organic carbon (OC) in PM2.5 atmospheric aerosol were measured at four different sites in Beijing: Beijing Olympic Forest Park (OF), Jiufeng National Forest Park (JF), Beijing Forestry University campus lawn (G), and roads near the Beijing Forestry University (S). The winter heating period concentrations were 30–45% higher than the spring non-heating period. Possible reasons for this could be the severe convective weather in spring due to the temperate monsoon, deposition of PM2.5 to plants in spring, stable atmospheric conditions in winter, and/or a greater number of sources of carbonaceous aerosols in winter. The proportion of total carbon (i.e. EC + OC) in PM2.5 in Beijing is high. The OC/EC value was 2.45 (OF) and 2.39 (JF) in winter and 1.6 (OF) and 1.43 (JF) in spring. These ratios and the high correlation of OC with EC in the winter samples indicate a strong primary source of OC. Eight carbon fractions from the four different sampling locations were analysed, and the OC1–4 values were found to vary considerably. In winter, the OC1 values from all four sites were higher than the spring values. Although there were differences at each site, the percentages of OC2, OC3, EC1-OP, and EC2 were the largest. Secondary organic carbon (SOC) formed during long-range transport from the emission sources to the monitoring sites, and the increase of OC2 and OC3 concentrations could be associated with SOC.

Performance Evaluation of a Self-Developed Ozonesonde and Its Application in an Intensive Observational Campaign

To make a detailed test on the reliability and detection performance of the electrochemical concentra- tion cell (ECC) type ozonesonde which had been devel- oped and preliminarily evaluated by the authors, an inten- sive ozonesonde release experiment was held at two sites in Beijing and Changchun in June 2013. The results showed that the mean background current and its standard deviation were 0.03 (0.04) μA and 0.02 (0.03) μA in Bei- jing (Changchun). The average response time and its standard deviation were 27.8 s (30.4 s) and 4.0 s (3.7 s) in Beijing (Changchun). The ozone partial pressure profiles at both sites showed a central peak in the stratosphere and a side peak in the boundary layer. Large variation in ozone partial pressure was observed at the middle levels of the atmosphere (10-17 km). A more marked gradient of ozone change was observed in Beijing (3.4 mPa km -1 ) at the lower atmosphere level, as compared to that in Changchun (0.4 mPa km -1 ). The results presented in this paper indicate that this self-developed ozonesonde shows a high level of reliability and good performance. The ozonsonde is expected to play an important role in opera-

Long-term (2001–2012) concentrations of fine particulate matter (PM&amp;lt;sub&amp;gt;2.5&amp;lt;/sub&amp;gt;) and the impact on human health in Beijing, China

Abstract. Beijing, the capital of China, is a densely populated city with poor air quality. The impact of high pollutant concentrations, in particular of aerosol particles, on human health is of major concern. The present study uses aerosol optical depth (AOD) as proxy to estimate long-term PM2.5 and subsequently estimates the premature mortality due to PM2.5. We use the AOD from 2001 to 2012 from the Aerosol Robotic Network (AERONET) site in Beijing and the ground-based PM2.5 observations from the US embassy in Beijing from 2010 to 2011 to establish a relationship between PM2.5 and AOD. By including the atmospheric boundary layer height and relative humidity in the comparative analysis, the correlation (R2) increases from 0.28 to 0.62. We evaluate 12 years of PM2.5 data for the Beijing central area using an estimated linear relationship with AOD and calculate the yearly premature mortality by different diseases attributable to PM2.5. The estimated average total mortality due to PM2.5 is about 5100 individuals per year for the period 2001–2012 in the Beijing central area, and for the period 2010–2012 the per capita mortality for all ages due to PM2.5 is around 15 per 10 000 person-years, which underscores the urgent need for air pollution abatement.

Ground-level ozone in urban Beijing over a 1-year period: Temporal variations and relationship to atmospheric oxidation

Regional ozone pollution has become a major environmental concern in China, especially in densely populated and economically vibrant regions such as North China, including Beijing. To address this issue, surface ozone and its precursors (CO, NO, and NO2) from December 2012 to November 2013 at 12 sites in urban Beijing and 2 sites in suburban Beijing were analyzed. The annual average concentrations of O3, CO, NO, and NO2 in urban Beijing were 45.5±50.2μgm−3, 1.5±1.3mgm−3, 27.3±42.7μgm−3, and 58.3+32.0μgm−3, respectively. The concentration of ozone was highest during summer, whereas concentrations of its precursors were highest during winter. Diurnal variations in ozone presented as a single-peak curve, with the peak appearing at about 15:00–16:00. Diurnal variations in most ozone precursors showed bimodal curves; the first peak appeared at about 08:00–09:00, and the second peak appeared at night. Hourly concentrations of ozone on the weekend were higher than those on weekdays between 11:00 and 24:00 in urban Beijing, which was suggestive of a significant weekend effect. This may be because NO inhibition on the weekend is weaker than that on weekdays during the ozone formation phase. Diurnal variations in OX (NO2+O3) showed a single peak, which appeared at 15:00 or 16:00. The results of correlation analysis among OX, O3, and NO2 suggested that OX was mainly controlled by O3 during the day and by NO2 during the night throughout the year. OX was controlled by NO2 during both the day and night during winter due to the low concentration of O3. The regional transport of ozone along the upwind direction was found in a typical ozone pollution event in summer in Beijing.

Aldehydes in relation to air pollution sources: A case study around the Beijing Olympics

This study was carried out to characterize three aldehydes of health concern (formaldehyde, acetaldehyde, and acrolein) at a central Beijing site in the summer and early fall of 2008 (from June to October). Aldehydes in polluted atmospheres come from both primary and secondary sources, which limits the control strategies for these reactive compounds. Measurements were made before, during, and after the Beijing Olympics to examine whether the dramatic air pollution control measures implemented during the Olympics had an impact on concentrations of the three aldehydes and their underlying primary and secondary sources. Average concentrations of formaldehyde, acetaldehyde and acrolein were 29.3 ± 15.1 μg/m3, 27.1 ± 15.7 μg/m3 and 2.3 ± 1.0 μg/m3, respectively, for the entire period of measurements, all being at the high end of concentration ranges measured in cities around the world in photochemical smog seasons. Formaldehyde and acrolein increased during the pollution control period compared to the pre-Olympic Games, followed the changing pattern of temperature, and were significantly correlated with ozone and with a secondary formation factor identified by principal component analysis (PCA). In contrast, acetaldehyde had a reduction in mean concentration during the Olympic air pollution control period compared to the pre-Olympic period and was significantly correlated with several pollutants emitted from local emission sources (e.g., NO2, CO, and PM2.5). Acetaldehyde was also more strongly associated with primary emission sources including vegetative burning and oil combustion factors identified through the PCA. All three aldehydes were lower during the post-Olympic sampling period compared to the before and during Olympic periods, likely due to seasonal and regional effects. Our findings point to the complexity of source control strategies for secondary pollutants.

Seasonal Trends of Polycyclic Aromatic Hydrocarbons in Particulate Matter at an Urban Site in Beijing, China

This study was conducted to examine the impact of vehicular traffic emissions on the seasonal trends of polycyclic aromatic hydrocarbons (PAHs) concentration in particulate matter in Beijing. The PM10 and PM2.5 samples were collected at an urban site near the Third Ring Road in Beijing, China, from July 2009 to March 2010. Individual PAH concentrations at urban traffic site ranged from n.d. (below the detection limit, 0.2 ng/m3) to 558.49 ng/m3 of benzo(b)fluoranthene in PM10 samples and from n.d. to 177.93 ng/m3 also for benzo(b)fluoranthene in PM2.5 samples. Seasonal variations of PAHs compounds indicated that PAHs concentration in autumn and winter was higher than those in spring and summer. Results of PCA give four and five significant factors, which could explain 83.1% of the variation for PM2.5 and 85.3% of the variation for PM10, respectively.

The Capital of the Yuan Dynasty by Chen Gaohua

Reviewed by: The Capital of the Yuan Dynasty by Chen Gaohua Nancy Shatzman Steinhardt Chen Gaohua. The Capital of the Yuan Dynasty. Translated by Phoebe Poon. Edited by Glenn Griffith and Phoebe Poon. Honolulu: Silkroad Press, 2015. Pp. viii + 214. $138 (cloth). ISBN 978-9814332446. Often there is no clear reason a Chinese book is selected for translation into English. This is the case for the recent translation of Chen Gaohua's 陳高 華 Yuan Dadu 元大都, published in 1982 by Beijing chubanshe.1 A reliable translation of the text as well as the notes and chronology, The Capital of the Yuan Dynasty is aimed at a knowledgeable reader. Useful end matter is included—a list of Yuan dynasty (1267–1368) emperors, Chinese units of measure used in the Yuan period, a character glossary, names of buildings in English translation and with Chinese characters, names and translated names of official titles, and an index—but only the ruler list would be useful to a general readership. The bibliography is only slightly updated to reflect relevant research of the thirty-three years since the publication of Yuan Dadu. The forward is a translation of Chen Gaohua's own, six sentences that do not even provide the dates of the Yuan dynasty or inform a reader that it was an era of Mongolian rule. One learns only that Dadu means great capital, that it was a predecessor to Beijing, and that "Turkic" peoples called it Khanbaliq. Chapter One, "Beijing Prior to the Establishment of Dadu," follows immediately. Although the reader is informed that the history of Beijing traces to the ancient past, the subjects are post-ninth-century cities, Yanjing 燕京 of the Liao dynasty and Zhongdu 中都 of the Jin. Here one observes both the strengths and disappointments of the book. The strengths are present in every paragraph. In sixteen pages, nearly eighty primary sources on these two cities are cited, relevant passages are summarized, statistics such as the record that Liao Yanjing had a population of 300,000 are analyzed (p. 6) and declared an exaggeration, titles are translated, and poems such as one on the fall of Jin [End Page 387] Zhongdu to the Mongols are translated as well (p. 18). Yet since the 1960s it has been known that the only way to investigate a Chinese city or building site is through a combination of primary sources and excavation reports. None of the archaeological data about the Liao or Jin predecessors to Dadu is given. The second chapter, "The Construction of Dadu," begins with a discussion of government organization focused on the role of the group the translator calls governors (here spelled jarghuchi). It then touches on the move of the Mongol capital from Qara-Qorum to Shangdu 上都 to Dadu, Khubilai's construction of Qionghua Island 瓊華島, the Palace Maintenance and Crafts Offices, Palace of the Moon, and eventually palace- and imperial-cities. Chen then turns to water works construction. The last paragraphs of the chapter assess Dadu's population, 147,590 households according to the census of 1270. At least 100,000 households is the estimate in other sources, with the claim in 1340 that Dadu had a population of one million (p. 35). Chen presents this information but does not assess it beyond suggesting that the last number is likely to be an exaggeration. Near the end of the chapter is the statement: "The new capital was built on multiple layers of exploitation." Perhaps an appropriate statement in 1982, but one an editor might have removed in 2015. To this point there have been four illustrations, pictures of Khubilai and Liu Bingzhong 劉秉忠 and two sites in Beijing. Finally in Chapter Three, "The Layout of Dadu," the reader finds two plans. Pictures of walls, pagodas, and gates, including Heyimen 和義門 that was tragically torn down at the peak of the Cultural Revolution, are omitted from the translation. Still, interesting facts and episodes in the city's history are included, and they are well translated. One example is the failed attempt to use reeds (wei 葦) to strengthen walls against erosive rain (pp. 39–40). Another is found in discussion of the imperial-city (huangcheng 皇城): the reader learns from the translation of a passage in Xiao...

Polybrominated diphenyl ethers in atmosphere from three different typical industrial areas in Beijing, China

Three common industries that cause polybrominated diphenyl ethers (PBDEs) pollution in Beijing, China, are solid waste incineration, chemical manufacturing, and coal-fired thermal power generation. This study was conducted to determine both the concentrations and profiles of 42 PBDEs in gaseous and particulate matter (including PM2.5, PM2.5–10, and total suspended particulate (TSP)) from the major industries listed above at three sites in Beijing. The total concentration of PBDEs (defined as the sum of 42 congeners in gas and TSP) were 60.5–216pgm−3 at the solid waste incineration plant, 71.8–7500pgm−3 at the chemical plant, and 34.4–454pgm−3 at the coal-fired thermal power plant. The results indicate that the components of PBDE in gas were similar between three industrial sites, and the dominant congener was tri-BDEs. However, in particulate matter, the dominant BDEs were different between the three sites, possibly because they originated from different sources. In particulate matter, the dominant PBDEs were penta-BDEs at the solid waste incineration plant, deca-BDE at the coal-fired thermal power plant, and tetra-BDEs and deca-BDE at the chemical plant. Source analysis revealed that PBDE contamination might be associated with the use of different commercial PBDE flame-retardant mixtures. Results from a previous risk assessment indicated that the risk to human health was low. However, results from this study suggest that there is a potential threat associated with human exposure to PBDEs for the residents near these industrial sites.