Accumulating characteristics of platinum group elements (PGE) in urban environments, China

The three-way catalytic converters [mainly using platinum, palladium and rhodium of platinum group elements (PGE)] have been widely used to reduce the pollution arising from vehicular traffic. Since the late 1990s, the Chinese government has implemented measures for new vehicles, equipped with the three-way catalytic converters in metropolitan cities. However, the PGE spreading on environments has not been strongly concerned in developing countries. This study investigated the accumulation characteristics of PGE in urban environments in China. A few samples from India were also analyzed and compared with those from China. The collected soil, aerosol and plant samples were determined for PGE by inductively coupled plasma-mass spectrometry (ICP-MS) after nickel sulphide fire assay preconcentration. The results have shown higher PGE contents in the samples from the cities where vehicles were fitted with autocatalysts for longer time periods. The highest values are 160 ng/g for Pt, 107 ng/g for Pd and 34.5 ng/g for Rh in Hong Kong soils, whereas the lowest values are 2.59 ng/g for Pt, 1.31 ng/g for Pd and 0.40 ng/g for Rh in Kolkata soils. In Beijing and Guangzhou aerosol samples, the PGE concentrations are 6.22 to 24.3 pg/m³ for Pt and 1.16 to 8.60 pg/m³ for Rh and 7.68 to 12.2 pg/m³ for Pt and 2.15 to 5.15 pg/m³ for Rh, respectively. The levels of PGE abundances in the urban environments of China have been significantly elevated with increasing number of vehicles equipped with autocatalysts.     

A further discussion of the factors controlling the distribution of Pt, Pd, Rh and Au in road dust, gullies, road sweeper and gully flusher sediment in the city of Sheffield, UK

Forty paired road dust and gully sediments from the city of Sheffield in NE England show that high platinum, palladium and rhodium concentrations derived from catalytic converters depend on proximity to both roundabouts rather than traffic lights and to topographic lows. Road dust outside schools and control samples, further away on the same road, show that Pt, Pd and Rh concentrations are dependant on passing traffic flow rather than numbers of stopping vehicles. Highest values of Pt + Pd in road dust are 852 ppb and 694 ppb in gullies. Rh has maximum values of 113 ppb in road dust and 49 ppb in gullies. Pt and Pd values of a few ppb to just over 100 ppb occur in road dust where traffic does not stop, on roads away from junctions. Pt, Pd, Rh and Au are all picked up by road sweepers and gully flushers both with maximum values of just over 100 ppb Pt and Pd. High Au values (maximum 610 ppb in a road dust) were located on pavements, in suburbs, outside schools and in road sweepers collecting in residential areas rather than on high traffic flow roads. Stratification of Pt and Pd in gullies was not observed whereas a high Au value was recorded at the bottom of a gully suggesting gravity concentration for Au. Anomalous Pd grades of 1050 ppb in road dust from a school entrance and 2040 ppb in a street sweeper sample were recorded. These high Pd- and Au-bearing samples do not have anomalous Pt or Rh values and may be sourced from jewellery or dental fillings. However, most samples have consistent Pt/Pd ratios of about 1 and Pt/Rh values of 4 to 5 indicating a catalytic converter source. Pt and Pd are concentrated in road dust at levels well above background in all the samples, including on high and low traffic flow roads.     

The estimation of the bioavailabilities of platinum, palladium and rhodium in vehicle exhaust catalysts and road dusts using a physiologically based extraction test

Platinum group element (PGE) levels in the environment have increased following the introduction of vehicle exhaust catalysts (VECs). In order to evaluate the potential pathways of PGEs from VECs into humans, a physiologically based extraction test (PBET) was used to study the uptake of PGEs by the human digestive tract. The PBET assay was implemented in two phases, to first simulate the passage of ingested soil through the acid conditions of the stomach before it enters the near neutral conditions of the small intestine. The results showed that Pt, Pd and Rh did not undergo precipitation reaction when passing from the acid environment of the stomach to the neutral environment of the small intestine. The greatest fractions of bioavailable PGEs (up to 68%) were observed in road dust samples, possibly due to the presence of mobile PGE species formed in the roadside environment. Higher percentages of Pd and Rh were bioavailable than Pt, probably due to the differences in their mobilities and tendencies to form soluble complexes. Pt showed the highest absolute bioavailability however, due to its greater concentration in environmental samples. The solubilization of PGEs in the human digestive tract could involve the formation of PGE-chloride complexes, with perhaps increased health-hazard issues because of the known toxic and allergenic effects of these species.     

Micropolitan areas: Exploring the linkages between demography and land-cover change in the United States cities

Micropolitan statistical areas in the United States are important transitionary regions that may provide insights into the economic, demographic, and social forces driving urbanization. Land cover change may provide significant insights into the dynamics of these important transitionary units. Our work investigates three questions: (1) How is the national landscape changing within micropolitan statistical areas with regards to land cover? (2) Are land-cover conditions in micropolitan areas closer to rural or metropolitan areas or are they unique? (3) How closely are demographic patterns linked to land conversion for development within micropolitan areas?When compared to metropolitan and rural areas within the US, our results demonstrate that micropolitan areas are unique with regards to the total amount of developed land, as well as land conversion to development. Within the micropolitan areas, we show that demographic categories such as population, population density, or population growth are not adequate predictors of land-cover change and that the geographic patterns of land conversion for development may provide valuable insights into the impact of micropolitan areas on the US national landscape.     

英国GIS高等教育与城市规划实践

本文结合城市规划等行业对高等院校毕业生的GIS技能的需求对英国大学中GIS教学培训的情况作一简单介绍,并通过若干实例就英国大学地理规划类院校的GIS辅修课程的讲授范围及深度要求、地理及计算机等院校GIS专业的课程设置结构等方面提供一些具体信息,供中国有关大专院校参考。     

Perfluorooctane sulphonate in raw and drinking water sources in the United Kingdom

There has been increasing interest in the widely used perfluorinated chemicals such as perfluorooctane sulphonate (PFOS). PFOS has been shown to be toxic, persistent and bioaccumulative in the environment and is a focus for restriction within the European Union. Limited monitoring data, especially in the United Kingdom, are available for PFOS in environmental waters, and even less for its detection in drinking water. Data available in the United Kingdom indicate that PFOS contamination of environmental waters has only occurred following specific incidents. Monitoring of 20 raw and treated drinking water sites in England, covering four seasonal periods, showed that PFOS is not a widespread background contaminant of raw and treated drinking water in England. Low levels of PFOS (0.012–0.208 μg/L) were detected at four specific sites, which were at a higher risk for contamination. At three of these sites, where PFOS was detected in both raw and final drinking water, treatment processes [chlorination, ozonation and granular activated carbon (GAC)] did not appear to remove PFOS. The findings of this work are pertinent to risk assessments now required by the drinking water quality regulations.     

Airborne particulate matter, platinum group elements and human health: A review of recent evidence

Environmental concentrations of the platinum group elements (PGE) platinum (Pt), palladium (Pd) and rhodium (Rh) have been on the rise, due largely to the use of automobile catalytic converters which employ these metals as exhaust catalysts. It has generally been assumed that the health risks associated with environmental exposures to PGE are minimal. More recent studies on PGE toxicity, environmental bioavailability and concentrations in biologically relevant media indicate however that environmental exposures to these metals may indeed pose a health risk, especially at a chronic, subclinical level. The purpose of this paper is to review the most recent evidence and provide an up-to-date assessment of the risks related to environmental exposures of PGE, particularly in airborne particulate matter (PM).This review concludes that these metals may pose a greater health risk than once thought for several reasons. First, emitted PGE may be easily mobilised and solubilised by various compounds commonly present in the environment, thereby enhancing their bioavailability. Second, PGE may be transformed into more toxic species upon uptake by organisms. The presence of chloride in lung fluids, for instance, may lead to the formation of halogenated PGE complexes that have a greater potential to induce cellular damage. Third, a significant proportion of PGE found in airborne PM is present in the fine fraction that been found to be associated with increases in morbidity and mortality. PGE are also a concern to the extent that they contribute to the suite of metals found in fine PM suspected of eliciting a variety of health effects, especially in vulnerable populations. All these factors highlight the need to monitor environmental levels of PGE and continue research on their bioavailability, behaviour, speciation and associated toxicity to enable us to better assess their potential to elicit health effects in humans.     

Regulating sanitation services in sub-saharan africa: An overview of the regulation of emptying and transport of faecal sludge in 20 cities and its implementation

Onsite sanitation is widely used in Sub-Saharan African (SSA) cities. Safe transportation and emptying of the resulting faecal sludge are essential for healthy cities. Typically provided by an informal and unmonitored private sector, these services are being increasingly regulated. This research provides an overview of the regulatory mechanisms in place in 20 cities across SSA, their implementation and emerging common trends. Findings highlight the diversity of tools, mechanisms, and capabilities. We conclude that incremental and pragmatic change is needed to achieve fully regulated services, with adequate implementation particularly facilitated by support and incentive mechanisms, and participation of all stakeholders.     

Transport and mobility in sub-Saharan African cities: An overview of practices,lessons and options for improvements

Urban mobility is increasingly becoming one of the planning and development issues for cities in the sub-Saharan Africa (SSA) region. Sub-Saharan cities are growing fast, outstripping the current transport infrastructure. Despite the population and spatial growth, many cities are defined by inadequate planning, rapid urbanisation and deteriorating transport infrastructure and services. In most sub-Saharan African countries, modes of urban mobility are highly dependent on income. Transport options are limited. In fact, walking and cycling are often the main means available for the majority of city commuters. Little effort is made to develop a range of transport options or to improve bike or walking paths. Combined with traffic jams, poor governance and the increasing cost of living, public transport mobility in sub-Saharan cities is having a tremendous impact on their liveability and citizens development aspirations. This paper argues that inclusive and broad ranging transport planning must be prioritised in SSA cities to improve the capacity of citizens to participate in work opportunities as well as to fulfil their daily domestic needs. Using observations and comparing progress in other countries and regions, we note that the majority urban poor, women in particular, are often bearing the brunt of inadequate planning and transport provision. We note that urban planning and transport infrastructure should therefore be (re) designed with particular focus on the wellbeing of the poor. The paper thus ends with a range of suggestions on what planning, design and policy options might be available to better integrate various commuting modes into urban planning infrastructure. In doing so, the paper notes that safety and security are critical elements of improving urban and spatial transport planning in the sub-Saharan Africa region.     

GIS在英国等欧洲国家及中国城市规划管理中的应用

本文结合若干实例介绍了GIS技术在英国等欧洲国家的规划管理与设计工作中的发展与应用现状,并总结了其应用经验与教训。对于一些具有规划应用潜力的GIS相关技术,本文也予以简单评价。最后就一些与GIS在中国规划设计管理中应用的有关问题提出了一些个人看法。     

英国历史土地利用评价(HLA)研究的 经验与启示

历史土地利用评价(Historic Land-use Assessment, HLA)是在时间深度(Time Depth,TD)下对历史环境中文化与自然的发展过程进行定性分析与数字化解译的过程,其结果可展现人地互动过程中遗留或呈现的风景特质。通过总结英国历史土地利用评价(HLA)的发展历程、目标和方法等内容,综合HLA在分析土地时空演变动态过程中的优势,探讨将融合文化-自然双重属性的评价方法应用于中国自然保护地的保护与建设之中,以期为我国自然保护地主要保护对象的确定、保护边界的优化、功能分区的划分等提供参考。     

The value of sewage sludge to agriculture and effects of the agricultural use of sludges contaminated with toxic elements: A review

The effects of organic matter, nitrogen, phosphorus and toxic elements in sewage sludges applied to agricultural land are reviewed. Organic matter may improve the structure and water holding capacity of poor soils and the nitrogen and phosphorus in sludge have fertiliser value. However, an important consideration in applying sludge to land is the limitation of addition of toxic elements and any beneficial effects are secondary to this. Crops can accumulate toxic elements from sludge-amended soils and where heavily contaminated sludges and excessive rates of application are used plants may accumulate concentrations which are phytotoxic. The extent of accumulation varies considerably with plant species and cultivar; cereals and legumes accumulating lower concentrations than leafy plants such as lettuce and spinach. Although guidelines limit the addition of toxic elements in sludges and soils, thus reducing the quantities of these elements accumulated by plants, total concentrations of toxic elements in soil provide no indication of their availability to plants. The procedures applied to the determination of the forms of elements in sludges and soils and attempts to relate forms extractable in a variety of reagents to their availability to plants have been discussed. The factors which influence the forms of nutrient and toxic elements, their long term availability and hence their accumulation by crops are also reviewed.     

Urban growth: Changes,management, and problems in large cities of Southeast China

Compared with medium-sized cities, megacities play an increasingly important role in the rapid urbanization process in China. Owing to the expanding scale of large cities, urban sprawl leads to unsustainable practices that cause ecological, social, and environmental problems. Urban planning and land use planning are major driving forces of land use and land cover change in China. However, the goals of these two types of planning are different, and coordinating them is a challenge for local government decision makers. Thus, we use the SLEUTH model to simulate the implementation scenarios of future urban growth in Nanjing in the Jiangsu province of China. Using the scientific simulation data of the model, we contrasted the alternative futures of the two planning types for local government decision makers to achieve sustainable urban planning.The objective of our study is to explore the problems and possible solutions for urban management in the context of amegacity in China. The results of our study confirm the value of SLEUTH, which provid esextensive exploratory knowledge in evaluating the effects of possible local government decisions.     

The concentration and distribution of some stable elements in healthy human tissues from the United Kingdom An environmental study

The mass of between 50 and 60 of the chemical elements present in various healthy human tissues has been studied and quantitative results are reported for about forty elements. The methods of analysis used were spark source mass spectrometry, X-ray fluorescence and various radioactivation methods.The merits of reconnaissance studies for a large number of elements are discussed with particular reference to the value of such data when considering possible relationships between the abundance of the chemical elements in man and human morbidity. The need for a true interdisciplinary approach when attempting to relate the abundances of the chemical elements in man to human morbidity is emphasized. A similarity between the shape of the abundance curve for the elements present in human tissues and average crustal rocks is discussed together with comments upon the chemical elements present in man and those in the natural environment.The mass of the chemical elements in human tissues from the United Kingdom is compared with data from elsewhere and suggests that only small differences exist for the mass of most elements present in the materials which have been examined. If some chemical elements present in man should be responsible for various types of disease then general reconnaissance studies will have to be supported by quantitative measurements in well defined environments.The samples of blood, amounting to ～2500 individual samples for which limited data are presented, may serve to provide a useful historical sequence of samples for the years 1968–1969.     

The performance of tertiary lagoons in the United Kingdom: I

Two tertiary lagoons at Holmwood Sewage Treatment Works in the United Kingdom were sampled over a 1 year period. Each lagoon is approximately 39×28 m, receives domestic wastewater only, and serves approximately 2000 people. The aim of the work is to gain a greater understanding of the performance of the lagoon with respect to a number of chemical, biological and physical parameters. Samples were analysed for E. coli, enterococci, total coliforms, BOD, COD, suspended solids, ammoniacal nitrogen, nitrite, nitrate, total oxidised nitrogen and soluble phosphate. Occasional samples were also analysed for Cryptosporidium, Giardia and enteroviruses. Cusum charts were used to analyse the cumulative variations that were seen for the parameters being investigated, and had the advantage of emphasising their distinct seasonal trends. Although good percentage removals were seen, there was a lack of consistency in performance for all parameters over the year. No ammonia or phosphorus removal was found, although limited nitrification does appear to occur. None of the bacterial criteria for the WHO guidelines on wastewater reuse or the EC directive on bathing water were reached.     

城市记忆与复兴--上海城市雕塑艺术中心的实践

上海城市雕塑艺术中心通过保护性改造和功能重塑,将一座曾经十分辉煌而今不再使用的老厂房打造成一座独特的艺术殿堂,实践了一条既能保留城市记忆、延续城市文明,又能展现城市新的艺术活力的城市工业文化遗产再造之路。     

Migrants'' dreams and planners'' nightmares: International labour migration in the Arab world and the growth of two sets of cities

"The author investigates how trends in international labour migration in the Arab world have been paralleled by new directions in migration research....[She] seeks to evaluate why the urban impact of international migration is so great and outlines the considerable potential which exists for pursuing research on this aspect of urban development."     

Climatic city: Two centuries of urban planning and climate science in Manchester (UK) and its region

This paper traces the history, and current challenges, of climate science and urban design in Greater Manchester, UK. The Mancunian metropolis is a remarkable example of a ‘climatic city’, one that shapes its climate as much as it is shaped by it. From the efforts to control smoke and clear slums in the 19th century, to today’s race to be at the forefront of ‘green’ and ‘sustainable’ cities, climate is a central actor in Manchester’s history and will likely be so in the near future. We analyse the continuities and inflections of this history of climate science and urban planning in the metropolis by drawing on historical material and interviews with key local stakeholders, to understand the natural, social and political construction of this singular ‘industrial ecology’. Ultimately, we ask whether stakeholders in the Greater Manchester area can overcome existing challenges to go towards a greener, more resilient and sustainable city.     

Tracer study and profiling of a tertiary lagoon in the United Kingdom: II

Monitoring data over a year showed that the performance of a tertiary lagoon system in the United Kingdom was very variable. Distinct seasonal patterns were seen for all the determinands. Tracer studies and profile sampling of one of the lagoons were carried out in order to investigate the factors affecting performance. The tracer studies, using sodium fluoride, indicated that the hydraulic regime was dispersed plug flow. The mean retention time was found to be 26 h, but the peak in tracer concentration occurred after 12 h, showing significant short-circuiting. During the profile sampling, the pH, temperature, DO and conductivity were measured down through the lagoon at 16 positions and four depths. E. coli, enterococci and total coliform numbers were measured in samples taken from the surface and the base of the lagoon. The results showed temperature decreased down through the lagoon, but the other parameters increased with depth, indicating that the short-circuiting was caused by the cooler influent sinking to the base of the lagoon.     

增长、结构和效率——兼评中国城市空间发展模式

研究表明,中国的城市空间发展存在六种缺少效率的典型形态,分别是：分散组团式发展,破碎化的土地开发、过度规模的土地开发,蛙跳式发展．空间随机式发展,过度的混合用途。为推动城市可持续的空间发展,应增强城市规划中经济．定量、模型等方面的分析;引进市场机制,充分发挥土地价值对城市空间发展的作用,实行灵活和多样的城市规划建设标准,实行灵活的土地利用功能分区等措施。