Dispersion of vehicular emission in street canyons,Guangzhou City,South China (P.R.C.)

The concentrationof vehicular pollutants, wind, turbulence and traffic volume were measured in three different typical street canyons in Guangzhou City. Air dispersion in different types of urban canyons was compared. The configuration of a street is an important factor that influences air dispersion. In low wind conditions, it is rare that a stable vortex is formed in a canyon with irregular configuration. The movement of vehicles may dominate the flow near the surface of the narrow street canyon when tee wind at roof-level is weak. Simple operational models have been proposed. They performed well in predicting the air pollution due to vehicular emission in different street canyons in Guangzhou City.     

Traffic emission and its impact on air quality in Guangzhou area

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Assessment of traffic related air pollution in urban areas of Macao

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城市街口规划设计与城市空气环境的关系

 城市大气环境同时涉及到大气科学和城市规划理论.本文从建筑与生态环境协调的角度出发,通过对典型实测数据的分析,考虑建筑物与风的相互作用特点,论述了街口形式对街道污染物扩散效果的影响,并对街口的生态设计原则提出了建议.     

中国农业面源污染物排放量计算及中长期预测

利用第一次全国污染源普查数据,计算了我国内地31个省市自治区农业面源污染排放量,在此基础上,预测了2010—2030年农业面源污染情况.结果表明,2007年,我国农业面源污染的污染物总排放量为1057×104t,其中,COD排放量为825.9×104t,总氮为187.2×104t,总磷为21.6×104t,氨氮为22.4×104t.如果不加大对面源污染的治理力度,2020年前我国农业面源污染有加剧的趋势.在高排放情景下,2030年农业面源污染中COD排放量可能上升到1466.5×104t,面源污染需引起高度重视.目前,东部沿海地区是我国农业面源污染的主要排放区,但未来我国农业面源污染排放的空间分布可能趋于均衡.     

Effectiveness of national air pollution control policies on the air quality in metropolitan areas of China

Understanding the effectiveness of national air pollution controls is important for control policy design to improve the future air quality in China. This study evaluated the effectiveness of major national control policies implemented recently in China through a modeling analysis. The sulfur dioxide （SO2） control policy during the llth Five Year Plan period （2006-2010） had succeeded in reducing the national SO2 emission in 2010 by 14% from its 2005 level, which correspondingly reduced ambient SO2 and sulfate （SO42-） concentrations by 13%-15% and 8%-10% respectively over east China. The nitrogen oxides （NOx） control policy during the 12th Five Year Plan period （2011-2015） targets the reduction of the national NOx emission in 2015 by 10% on the basis of 2010. The simulation results suggest that such a reduction in NOx emission will reduce the ambient nitrogen dioxide （NO2）, nitrate （NO3-）, 1-hr maxima ozone （03） concentrations and total nitrogen deposition by 8%, 3%-14%, 2% and 2%--4%, respectively over east China. The application of new emission standards for power plants will further reduce the NO2, NO3-, 1-hr maxima 03 concentrations and total nitrogen deposition by 2%-4%, 1%-%, 0-2% and 1%-2%, respectively. Sensitivity analysis was conducted to evaluate the inter-provincial impacts of emission reduction in Beijing-Tianjin-Hebei and the Yangtze River Delta, which indicated the need to implement joint regional air pollution control.     

Efectiveness of national air pollution control policies on the air quality in metropolitan areas of China

Understanding the efectiveness of national air pollution controls is important for control policy design to improve the future air quality in China. This study evaluated the efectiveness of major national control policies implemented recently in China through a modeling analysis. The sulfur dioxide(SO2) control policy during the 11th Five Year Plan period(2006–2010) had succeeded in reducing the national SO2emission in 2010 by 14% from its 2005 level, which correspondingly reduced ambient SO2and sulfate(SO4 2) concentrations by 13%–15% and 8%–10% respectively over east China. The nitrogen oxides(NOx) control policy during the 12th Five Year Plan period(2011–2015) targets the reduction of the national NOx emission in 2015 by 10% on the basis of 2010. The simulation results suggest that such a reduction in NOx emission will reduce the ambient nitrogen dioxide(NO2), nitrate(NO3), 1-hr maxima ozone(O3) concentrations and total nitrogen deposition by 8%, 3%–14%, 2% and 2%–4%, respectively over east China. The application of new emission standards for power plants will further reduce the NO2, NO3, 1-hr maxima O3concentrations and total nitrogen deposition by 2%–4%, 1%–6%, 0–2% and 1%–2%, respectively. Sensitivity analysis was conducted to evaluate the inter-provincial impacts of emission reduction in Beijing-Tianjin-Hebei and the Yangtze River Delta, which indicated the need to implement joint regional air pollution control.     

Effects of air pollution on Pinus halepensis (Mill.): pollution levels in Attica,Greece

Air quality in the Athens basin is well known to be poor, damaging building materials and human health, but there is no information available on concentrations or the impact of oxidants on ecosystems in rural areas outside the basin. A short-term monitoring campaign, coupled with a survey using the O₃ bioindicator Bel-W3 tobacco demonstrated that phytotoxic concentrations of O₃ occurred throughout Attica, within a 75 km radius of the city. There was relatively little injury produced in the industrial centre of the city and maximum injury was found about 40 km to the SE. Visible lesions identical to those of O₃ injury were found on Aleppo pine at all sites in the cooler months. In the summer the needles were very chlorotic, possibly due to photo-oxidation of chlorophylls mediated by heat or drought. This chlorosis may mask oxidant symptoms in the summer. NO₂ diffusion tube data and needle analysis suggested that the effects of sulphur and NO₂ are probably confined to the Athens basin.     

宝鸡城市土壤重金属生物活性与环境风险

在野外调查与前期研究的基础上,根据一点多样混合采样法收集宝鸡市工业区土壤分析样品50个,采用Tessier连续形态分析法对城市土壤重金属Pb、Zn、Cd、Cr、Cu、Sb形态进行分级并使用ICP-OES对其各形态含量进行测定.在对6种重金属活性系数(MF)、迁移系数(MJ)、综合潜在生态风险指数(RI)及人群健康风险研究的基础上,对重金属地球化学形态分布、迁移能力、生物活性与环境风险进行了探讨.结果表明,宝鸡工业区城市土壤重金属Zn、Cd、Cr、Cu、Sb形态均以残渣态为主,而Pb主要以铁锰氧化物结合态为主;在各形态含量所占百分比中,重金属Cr可交换态含量最低.化学形态分析结果显示,6种重金属整体迁移的顺序为:Pb(77.60%)Zn(47.36%)Cu(35.86%)Cd(30.91%)Sb(16.46%)Cr(11.31%);土壤Pb(MF=35.77%)的生物活性最强,Cd(MJ=0.091)的迁移能力最大.城市土壤重金属Cd和Cr对儿童和成人的致癌风险处于中低等水平,但Cr对儿童将产生较大的非致癌风险.而重金属Pb对儿童和成人均产生非常明显的非致癌风险和中等程度的致癌风险,可见,重金属Pb是宝鸡市城市土壤最主要的环境污染物与健康风险因子.重金属Pb、Zn、Cd、Cr、Cu、Sb工业排放与化石燃料燃烧的来源和城市儿童高铅血症的检出率说明宝鸡工业区重金属的干湿尘降污染应该引起高度重视.     

济南城区空气污染对呼吸道疾病门诊量的影响

为探讨空气污染对人群呼吸道健康的影响,调查了2002~2005 年济南市历城区空气质量状况及医院每日呼吸道疾病门诊量,采用时间序列方法的非参数广义相加模型(GAM),在控制门诊量变化的长期趋势、“星期几效应”、气象因素等混杂因素的基础上,分析了空气污染对呼吸道疾病日门诊量影响的最佳滞后时间及暴露-反应关系.结果表明,空气污染对呼吸道疾病日门诊量有影响.单污染物模型中,PM₁₀ 和NO₂ 分别滞后0d 和3d 及SO₂ 滞后0~3d 的移动平均值对人群呼吸道健康的影响具有统计学意义.PM₁₀、SO₂ 和NO₂ 日均浓度增加10µg/m³,呼吸道疾病日门诊相对危险度分别为1.004, 1.015,1.008.女性比男性对空气污染更为敏感.     

Evaluation of ambient air quality in Guangzhou, China

On the basis of the reported air quality index （API） and air pollutant monitoring data provided by the Guangzhou Environment Monitoring Stations over the last twenty-five years, the characteristics of air quality, prominent pollutants, and variation of the average annual concentrations of SOE, NOE, total suspended particulate （TSP）, fine particulates （PM10）, CO and dustfall in Guangzhou City were analyzed. Results showed that TSP was the prominent pollutant in the ambient air environment of Guangzhou City. Of the prominent pollutants, TSP accounted for nearly 62%, SOE 12.3%, and NOx 6.4%, respectively. The average API of Guangzhou over 6 years was higher than that of Beijing, Tianjin, Nanjing, Hangzhou, Suzhou and Shanghai, and lower than that of Shenzhen, Zhuhai and Shantou. Concentrations of air pollutants have shown a downward trend in recent years, but they are generally worse than ambient air quality standards for USA, Hong Kong and EU. SOE and NOx pollution were still serious, impling that waste gas pollution from all kinds of vehicles had become a significant problem for environmental protection in Guangzhou. The possible causes of worsening air quality were also discussed in this paper.     

沈阳市空气污染特征

以沈阳市8个国控环境空气监测点位和一个清洁对照点位2004年全年小时浓度为基础数据,研究了沈阳市空气PM₁₀、SO₂和NO₂的季节变化、日变化、空间分布及综合污染指数(API)等空气污染特征,并用1995～2004年的监测数据,分析了沈阳市空气质量的总体变化趋势.结果表明,首要污染物为PM₁₀,其空气污染具有典型的煤烟型污染季节特征,环境空气质量在1995～2004年期间逐年好转.     

Impacts of pollution heterogeneity on population exposure in dense urban areas using ultra-fine resolution air quality data

Traditional air quality data have a spatial resolution of 1 km or above, making it challenging to resolve detailed air pollution exposure in complex urban areas. Combining urban morphology, dynamic traffic emission, regional and local meteorology, physicochemical transformations in air quality models using big data fusion technology, an ultra-fine resolution modeling system was developed to provide air quality data down to street level. Based on one-year ultra-fine resolution data, this study investigated the effects of pollution heterogeneity on the individual and population exposure to particulate matter (PM_2.5 and PM₁₀), nitrogen dioxide (NO₂), and ozone (O₃) in Hong Kong, one of the most densely populated and urbanized cities. Sharp fine-scale variabilities in air pollution were revealed within individual city blocks. Using traditional 1 km average to represent individual exposure resulted in a positively skewed deviation of up to 200% for high-end exposure individuals. Citizens were disproportionally affected by air pollution, with annual pollutant concentrations varied by factors of 2 to 5 among 452 District Council Constituency Areas (DCCAs) in Hong Kong, indicating great environmental inequities among the population. Unfavorable city planning resulted in a positive spatial coincidence between pollution and population, which increased public exposure to air pollutants by as large as 46% among districts in Hong Kong. Our results highlight the importance of ultra-fine pollutant data in quantifying the heterogeneity in pollution exposure in the dense urban area and the critical role of smart urban planning in reducing exposure inequities.     

Characteristics of air pollution by polychlorinated dibenzo-p-dioxins and dibenzofurans in the typical industrial areas of Tangshan City, China

The ambient air in vicinity of different industrial sources for PCDD/PCDFs was sampled by TSP/PM10 active samplers and passive PUF disk samplers in Tangshan City, a metropolis containing clusters of various industrial plants. The TEQ concentrations of PCDD/PCDFs ranged from 44.2 to 394.1 fg I-TEQ/m3 with an average of 169.9 fg I-TEQ/m3. 2,3,4,7,8-PeCDF was the dominant contributor to PTEQ, contributing 41% (12% to 55%), while 1,2,3,4,6,7,8-HpCDF, OCDD and OCDF were the major congeners for the total concentrations. The ratios of PPCDF/PPCDD reached 2.54 on average, suggesting that de novo synthesis in thermal processes played an important role to the airborne pollution of PCDD/PCDFs. The similarities congener profiles indicated that TSP and PM10 active sampling methods are comparable for the determination of the PCDD/PCDFs in ambient air, and the ratios of concentrations determined by the two methods suggested that the PCDD/PCDFs tended to stay in fine particles. It was found that 2,3,7,8-TCDF and OCDD were the dominating congeners in the passive PUF disks samples. Through principal components analysis, the coke industry was suggested to be a relatively high potential emission source for PCDD/PCDFs in the ambient air of Tangshan, which was possibly formed by de novo synthesis mechanism. In this study, the atmospheric impacts to the environment from di erent industrial sources could be ranked as follows (from high to low): coking, iron sintering, steel making, power generation and chlorinate alkali chemical production industries.     

广州市机动车尾气排放系数及污染趋势探讨

运用美国EPAMOBILE5尾气排放系数模式,结合广州市实际情况,进行了机动车排放系数的探讨,并据此预测了广州市机动车尾气排放浓度,估算了广州市机动车尾气排放在环境空气污染中所占的比例和所起的作用。对指导城市机动车污染排放控制提供了重要的参考依据。     

Landscape ecological analysis of urban vegetation in Guangzhou, China

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常熟市大气污染特征、健康风险评价及潜在源分析

利用常熟市2018—2020年空气质量自动监测站点的常规大气污染物数据对空气质量及主要污染物变化特征进行分析,并利用大气污染与健康暴露评价模型分析常熟市近年来大气健康风险特征,同时结合HYSPLIT后向轨迹模型,综合运用轨迹聚类及PSCF分析方法,计算不同季节影响常熟市城区的主要气流输送路径及常熟市O₃的主要潜在源区。结果表明：2018—2020年,常熟市空气质量明显改善,AQI达标天逐年增多,中重度以上污染天呈明显减少趋势,SO₂、PM_2.5、NO₂、PM₁₀浓度均呈下降趋势,大气污染防治效果显著。PM_2.5与O₃仍是影响常熟市空气质量的主要因素,其中O₃对于空气质量影响逐年增强。PM_2.5季节变化特征明显,冬季浓度最高,夏季最低;O₃浓度春夏季较高,冬季最低。常熟市大气污染物的健康风险同污染物特征分布趋于一致,具有显著的时间分布特征。颗粒物对人体健康的相对风险值处于较低水平,呈逐年降低趋势;而O₃的健康风险威胁总体上高于颗粒物,且在近两年逐渐上升,夏季对人体健康威胁风险等级达适中级别,造成死亡率/发病率的相对风险增加3%—5.1%。后向轨迹聚类分析结果表明常熟市夏季受南与东南方向气流影响较大,二者在夏季总气流轨迹中的占比高达66.21%。潜在源分析结果表明,常熟地区对人体健康威胁较大的O₃潜在源区广泛,主要分布在江苏北部、安徽南部、浙江东部地区,同时还存在部分广东地区的远距离输送。     

京津冀城市群大气污染传输规律研究——两组排放清单的比较分析

利用WRF/CALPUFF耦合模型,在同样重污染气象条件下,选择了当下模拟应用最广的两组排放清单对4种主要污染物（NO_x,SO₂,PM_2.5和PM₁₀）进行京津冀城市间区域传输贡献比较分析.其中一组排放清单来自政府的环境统计（以下称：环统排放清单）,另一组排放清单是来自中国多尺度排放清单（以下称：MEIC排放清单）.污染物的浓度空间分布表明,两种排放清单下污染物浓度均呈现北部以唐山中心,南部以石家庄-邯郸为中心的分布特征,均是由两个浓度最高的中心向外逐渐降低.但是环统排放清单下模拟的污染物浓度高值区范围更大,更接近实际监测数据.基于不同的清单输入,一些城市的传输角色存在一些差异.例如,对于4种污染物,两种排放清单模拟出的沧州与周边城市的净传输方向完全相反,在MEIC排放清单中,沧州以向外净传输为主,即为源;而在环统排放清单中,沧州则变成了净输入城市,即为汇.这些结论将影响大气联防联控中各城市源汇责任的认定,在实际环境管理中应注重多源数据的选择、验证和比较.     

广州市大气污染特征及其典型环流形势分析

基于2016—2019年空气质量监测数据、地面气象观测数据和中低层天气形势图,分析了广州市大气污染特征及其典型环流形势特征,揭示了不同环流形势与污染物浓度之间的关系.结果表明：(1)近年来广州市随着细颗粒物污染持续改善,空气质量优良率基本维持在80%及以上,但光化学污染问题逐渐凸显,O₃已成为广州市大气污染的主要污染物.(2)广州市大气污染季节变化明显,主要表现为秋、冬季更易出现大气污染,且多为持续性(≥5 d)污染.(3)经过分型和统计,总结出10种典型500 hPa-850 hPa-地面环流型,分别为台风外围-台风外围-台风外围、副高边缘-反气旋环流-变形高压脊、副高边缘-反气旋环流-冷锋前、副高-偏南气流-均压场、副高-偏东气流-均压场、副高-反气旋环流-均压场、副高边缘-反气旋环流-冷高压脊、西风槽槽后-反气旋环流-变性高压脊、副高-偏南气流-冷锋前、副高边缘-偏南气流-冷锋前.个例分析表明,这10种典型环流型可以概述最主要的广州大气污染环流形势,对空气质量预报有一定的指导作用.     

工业园及电子垃圾区大气中的溴代阻燃剂(BFRs)

对广州市主要的工业园以及清远电子垃圾回收拆解园周边空气中溴代阻燃剂（BFRs）进行了分析.结果表明,两地区大气中均以多溴联苯醚（PBDEs）和十溴二苯乙烷（DBDPE）为主（城市地区占比分别为30.0%和68.0%,电子垃圾区分别为74.5%和22.8%）,其中PBDEs在城市地区和电子垃圾区的浓度中值分别为184和411pg/m³;DBDPE则分别为414和193pg/m³.在城市地区,PBDEs的浓度高值多出现在与机械、电子、装饰材料和汽车制造业有关的工业园,新型阻燃剂DBDPE高浓度则多在与机械和电子产品制造业相关的大气中,而1,2-二（2,4,6-三溴苯氧基）乙烷（BTBPE）可能受当地面源污染影响较大.城市地区低分子量的PBDEs的组成波动较大,与五溴联苯醚的禁用（直接排放减少）和来源复杂有关;而电子垃圾区低分子量PBDEs组成稳定,气-固相分配更接近平衡,说明来源较为单一.通过模型估算,城市地区的21个工业园每年约向空气中释放48.0kg的BDE209与163kg的DBDPE,4个电子垃圾拆解园每年约释放31.8kg的PBDEs与12.0kg的DBDPE.