Hasil untuk "Metropolitan areas"

Xiaotao Peng, Xiaotao Peng, Ziling Tan et al.

Accelerating urbanization and industrialization in China has intensified land use conflicts (LUCs), requiring the identification of potential LUCs and their reconciliation to support the sustainable utilization of land resources. In this study, we established a hierarchical multi-criteria evaluation system for land use competitiveness from the perspective of land suitability and potential driving forces of land-use conversion. Based on this system, we measured the competitiveness intensity for construction, agricultural, and ecological land. Finally, a conflict identification matrix was used to determine the types and intensity of LUCs. We took Guangdong Province as the case study because it is one of the most economically dynamic regions in China and is experiencing severe LUCs. The results were as follows: the potential LUCs were more acute in the non-core areas of the Pearl River Delta, the Eastern Coastal Economic Zone, and the Western Coastal Economic Zone, but weak in agricultural advantage areas, economically developed metropolitan, and ecologically sensitive areas. The primary types of these conflicts were notably between agricultural and ecological land, between agricultural and construction land, and among three land use types, which accounted for 34.00, 10.40, and 10.51% of the provincial area, respectively. The conflict between agricultural land and ecological land mainly occurred in the interface between agricultural and forest ecosystems. Based on the scope, intensity, and spatial patterns of LUCs in each zone, we finally proposed targeted land use strategies and recommendations for different administrative regions. Our findings provide scientific evidence for sustainable land use planning and management in rapidly developing regions.

Ivan N. Alov, Marko D. Petrović, Alisa M. Belyaeva

Urban depopulation has become an increasingly visible phenomenon worldwide, affecting cities of different sizes and economic structures. This article develops a typology of U.S. depopulating cities beyond the Rust Belt’s iconic industrial cities, which dominate academic literature, to include a wider range of shrinking settlements in the shadows. The analysis is based on a dataset of U.S. census places constructed from decennial census population data (1990–2020) combined with employment structure indicators and spatial classification variables identifying metropolitan position and industrial specialization. Using 1990–2020 population change and three explanatory dimensions—city size, industrial heritage, and peripheral location—the analysis identified 1082 places that lost at least 10% of their population. Logistic regression showed manufacturing and mining reliance, small size, and remoteness as significant predictors of depopulation. Based on these factors, settlements are divided into seven types, from large urban centers to small peripheral towns with fewer than 5000 people. The overwhelming predominance of small towns (97%) in the sample highlights their distinct development challenges and questions the narrative of decline focused solely on larger industrial cities. By situating American trajectories within the broader shrinking cities discourse, the findings demonstrate the value of typology as a methodological tool for identifying intra-group heterogeneity, capturing regional differences, and establishing a more reliable basis for comparative urban studies. Ultimately, the study shows that urban decline in the United States is not exclusively a Rust Belt phenomenon, but a multidimensional process encompassing different scales, sectors, and geographies.

Carlos Lopez-Ordoñez, Elena Garcia-Nevado, Helena Coch et al.

As global warming increases, understanding the vulnerability of urban areas to extreme heat becomes crucial. Social housing districts, due to their urban form and demographic composition, are identified as high-risk areas for heat stress. This study investigates the impact of trees on mitigating outdoor heat stress in social housing districts, focusing on the Mediterranean region, particularly the metropolitan area of Barcelona, Spain. Using mean radiant temperature (MRT) as a key parameter, simulations were conducted to assess the influence of trees on heat stress in two districts differing in building types: linear blocks versus towers. The results show that the absence of trees makes towers more vulnerable to heat stress, as they lack long-term shaded spaces, such as the corridors in the linear blocks. In contrast, when trees are considered, tree-induced shading significantly decreases MRT and shifts its distribution pattern so that both urban fabrics exhibit similar performances, achieving the same percentage of open space with moderate heat stress (22%). These findings underscore the importance of a performance-based design approach, emphasising the need to consider both urban form and tree cover for effective heat stress mitigation in social housing districts. Policy relevance Shade planning plays a key role in shaping thermal comfort outcomes under heat-stress conditions. Urban fabrics with high open space ratios, typical of the European post-war modernist social housing boom, are especially vulnerable to this issue, underscoring the importance of integrating vegetation as a key component of green infrastructure and a critical microclimatic resource. This work emphasises the need for planning frameworks that recognise trees not only as design elements but also as essential urban infrastructure. By leveraging workflows compatible with geographical information system (GIS)-based tools used by urban practitioners, the study supports both the design and the management of green infrastructure through actionable, context-sensitive, heat-mitigation strategies. By enabling the identification of critical shade providers and assessing their performance under different morphologies, such tools can guide adaptive strategies, from tree placement to irrigation prioritisation, enhancing the resilience of urban environments to rising heat stress.

Aastha Gautam, Diya Malla, Aadarsh Khatiwada et al.

Managing solid waste is one of the emerging challenges in urban areas, and open dumping and burning is common practices mostly in developing countries like Nepal. Which affects the overall surroundings. The study has investigated the effects of open dumping and burning in nearby air, soil, and river water in dumping site of Biratnagar metropolitan city. For studying the effects on air, the three samples of air were taken, at center and 100m upstream and downstream to the direction of wind flow. Soil samples were taken at 10m from the dumping site center, at 25m from the first sample and at 60m from the second sample, and the water samples were taken at leachate and 100 m upstream and downstream to the leachate. Soil and water were subjected to the physiochemical test, heavy metals test and microbes test whereas PM 2.5, and PM 10 were tested for air  quality. The results showed that the air from upstream has been seen carrying particulate matter from the dumping site to downstream. Similarly, it is found that the quality of water at leachate and downstream is degraded compared to upstream. The soil quality has been found to have degraded due to the harmful and toxic material of the dumping site. Thus, this study shows that open dumping and burning have affected the nearby air, water, and soil.

Junjie Wang, Jialiang Guo

IntroductionIn recent years, China’s divorce rates have remained high, especially in metropolitan areas such as Beijing and Shanghai, where rates reach up to 40%. Additionally, there has been a notable shift towards younger demographics in divorce cases. In a society that highly values marital harmony, divorce is often seen as a cultural transgression. Anthony Giddens’ theory of disembedding and re-embedding provides a useful framework for understanding these changes. This study addresses a gap in literature by focusing on the online social interactions of divorced Chinese youth, exploring their use of dating apps for emotional support and social reconnections.MethodsThis qualitative study employed semi-structured interviews with 19 divorced young adults in China who engaged with dating apps such as Momo, Tantan, and Soul. Participants were recruited via Douban and Xiaohongshu. The interviews, conducted through WeChat voice calls and Tencent Meetings, lasted 45-70 minutes each. Data was analyzed using Nvivo12 to understand the disembedding and re-embedding processes in their online interactions, exploring themes such as motivations, self-presentation, and the transition from online to offline engagements.Results and discussionThe findings reveal that these individuals face societal challenges, biases, and the residual effects of past marriages, leading them to seek refuge in online environments to avoid stigmatization. In digital spaces, they cautiously engage, revealing a lack of confidence through selective self-disclosure. Their goals range from forming same-sex and opposite-sex friendships to seeking new romantic relationships, indicating a nuanced approach to remarriage and challenging stereotypes of dating app users. Re-engaging online, they discover social support and a sense of community, which aids in regaining confidence post-divorce, underscoring the complex interplay between societal influences and individual adaptation strategies in the digital age. The study highlights the unique challenges faced by this demographic, including maintaining anonymity and dealing with societal prejudices. Future research should consider a broader age range and gender differences to provide a more comprehensive understanding of the online behaviors and experiences of divorced individuals.

Qianqian Li, Ziwei Han, Guijin Su et al.

Microplastics (MPs) as emerging contaminants have become a major global concern, however, the distribution and origin of MPs in Qinghai-Tibet Plateau (QTP) and their impacts on ecosystem are poorly known. Hence, we systematically evaluated the profile of MPs on the representative metropolitan locations of Lhasa and Huangshui Rivers and the scenic sites of Namco and Qinghai Lake. The average abundance of MPs in the water samples was 7020 items/m3, which was 34 and 52 times higher than those for the sediment (206.7 items/m3) and soil samples (134.7 items/m3), respectively. Huangshui River had the highest levels, followed by Qinghai Lake, Lhasa River and Namco. Human activities rather than altitude and salinity impacted the distribution of MPs in those areas. Besides the consumption of plastic products by locals and tourists, laundry wastewater and exogenous tributary inputs, the unique prayer flag culture also contributed to the MPs emission in QTP. Notably, the stability and fragment of MPs were crucial for their fate. Multiple assessment models were employed to evaluate the risk of MPs. PERI model took MP concentration, background value and toxicity into account, comprehensively describing the risk differences of each site. The large PVC proportion in Qinghai Lake posed the highest risk. Furthermore, concerns should be raised about PVC, PE and PET in Lhasa and Huangshui Rivers, and PC in Namco Lake. Risk quotient suggested that aged MPs in sediments slowly released biotoxic DEHP and should be cleaned up promptly. The findings offer baseline data of MPs in QTP and ecological risks, providing important support for the prioritization of future control measures.

Zuxuan Song, Fangmei Liu, Wenbo Lv et al.

Exploring the transformation process of urban agricultural functions and its interaction with carbon effects based on regional differences is of great positive significance for achieving a low-carbon sustainable development of agriculture in metropolitan areas. By using the index system method, self-organizing feature maps (SOFM) network modeling, and Granger causality analysis, we divided the agricultural regional types of the Pearl River Delta (PRD) based on the spatio-temporal changes in urban agricultural functions and carbon effects at the county level in the PRD from 2002 to 2020, and analyzed the carbon effects generated by the agricultural functions according to the differences between the three agricultural regional types. The results show the following: (1) The changes in the basic functions of agriculture, the intermediate functions of agriculture, and the advanced functions of agriculture were different from the perspectives of both time and space. (2) The carbon effects produced by the areas with weak agricultural functions, the areas with medium agricultural functions, and the areas with strong agricultural functions were different. (3) The evolution of agricultural production types aggravated the grain risk in the PRD, and urban agriculture has potential in improving food security. (4) Based on the regional types of agricultural functions and considering the constraints of land and water, strategic suggestions such as integrating natural resources, improving utilization efficiency, upgrading technical facilities, and avoiding production pollution are put forward. (5) The green and low-carbon transformation of urban agriculture has its boundaries. The positive effects of the factors, namely the innovation of agricultural production methods, the change in agricultural organization modes, the impact of market orientation, and the transfer of the agricultural labor force, is limited. The findings of this paper provide valuable and meaningful insights for academia, policy makers, producers, and ultimately for the local population in general, driving the development of urban agriculture in a low-carbon and sustainable direction.

Ngangmo Yannick Cédric, Mezoue Adiang Cyrille, Mah Serges Charitos et al.

Introduction: In both developed and developing countries, re-suspension of dust particles along the road owing to tire and brake wear is the most common source of Particulate Matters (PM) pollution in metropolitan areas. This study in Douala analyses the effects of paved and unpaved roads on particle matters concentration thresholds in urban environments. Materials and methods: The United States Environmental Protection Agency (US EPA)'s model AP-42 equations were used to calculate the amount of particle matter emissions on the roads. Between 6 am and 8 pm, a traffic analysis using information from the city of Douala was conducted. The busiest times for traffic were from 8 to 9 a.m. and 6 to 7 p.m. We applied a two-dimensional Gaussian model to determine the particle concentration. Two different scenarios were taken into account: Compared to Scenario 2 (S2), Scenario 1 (S1) represents an unpaved road. The PM10 and PM2.5 types of particles were the main topics of interest. Results: We obtained for S1, around 917.70 µg/m3  and 559.00 µg/m3 respectively for PM10 and PM2.5. We got roughly 170.00 µg/m3 and 103.90 µg/m3 for S2, respectively for the two particles. The amount of silt deposited on the road, the kind of road (paved or unpaved), the number, and the types of vehicles moving all influence the emission of road dust re-suspension. Regardless of particle size, these pollution levels are beyond World Health Organization (WHO) recommended norms. Conclusion: This study offers important information on Douala's pollution levels, which can be a significant cause of disease in the area and should be considered.

R Franzsen

In terms of the Local Government: Municipal Property Rates Act 6 of 2004 (MPRA), metropolitan and local municipalities in South Africa may levy property rates on property. The MPRA provides for only one tax base, namely "market value". Given the paucity of skills and capacity to prepare credible valuation rolls and given the costs of doing so, especially B3 and B4 local municipalities situated in rural areas are struggling to comply with the valuation-related provisions of the MPRA. A brief review of property tax base options utilised globally indicates that some countries allow for different tax bases (or even different taxes) on the basis of the location and/or use of property and some jurisdictions apply simplified methodologies (such as value banding, points-based assessment or even self-assessment) to assess properties for property tax purposes. In the light of there being viable alternatives to market value and of the challenges faced by many rural local municipalities, the South African government should revisit the policy decision to have only market value as the tax base across vastly different types of municipalities.

Wendel Coura-Vital, Diogo Tavares Cardoso, Fabricio Thomaz de Oliveira Ker et al.

ABSTRACT COVID-19 is an infectious disease caused by the recently discovered coronavirus SARS-Cov-2. The disease became pandemic affecting many countries globally, including Brazil. Considering the expansion process and particularities during the initial stages of the epidemic, we aimed to analyze the spatial and spatiotemporal patterns of COVID-19 occurrence and to identify priority risk areas in Minas Gerais State, Southeast Brazil. An ecological study was performed considering all data from human cases of COVID-19 confirmed from the epidemiological week (EW) 11 (March 08, 2020) to EW 26 (June 27, 2020). Crude and smoothed incidence rates were used to analyze the distribution of disease patterns based on global and local indicators of spatial association and space-time risk assessment. Positive spatial autocorrelation and spatial dependence were found. Our results suggest that the metropolitan region of the State capital Belo Horizonte (MRBH) and Vale do Rio Doce mesoregions, as major epidemic foci in the beginning of the expansion process, have had important influence on the dispersion of SARS-CoV-2 in Minas Gerais State. Triangulo Mineiro/Alto Paranaiba region presented the highest risk of infection. In addition, six statistically significant spatiotemporal clusters were identified in the State, three at high risk and three at low risk. Our findings contribute to a greater understanding of the space-time disease dynamic and discuss strategies for identification of priority areas for COVID-19 surveillance and control.

Spencer D. Li, Ruoshan Xiong, Min Liang et al.

PurposePast research has documented a significant relationship between family violence and adolescent violence. However, much is unknown about the processes through which this association occurs, especially in the non-Western cultural context. To address this gap, we propose an integrated model encompassing multiple pathways that connect family violence to adolescent violence. Specifically, this study investigates how family violence is related to adolescent violence through violent peer association, normative beliefs about violence, and negative emotions.MethodWe tested the model using the two-wave survey data collected from a probability sample of more than 1,100 adolescents residing in one of the largest metropolitan areas in China in 2015 to 2016.Results and ConclusionsThe results indicated that family violence predicted adolescent violence perpetration. Violent peer association, normative beliefs, and negative emotions, however, mediated much of the relationship between family violence and adolescent violence.

Artan Hysa

Human activity combined with the dynamics of severe climate conditions are accepted the main drivers of wildfire events in the Mediterranean region. This fact is urging for further comprehensive research focusing on the wildland-urban interface (WUI) at metropolitan scale, at which the tension between the cause and effect of wildfire is the highest. In this context, the study brings a comparative case between two metropolitan areas from Western Balkan countries, the forest lands of which are classified by their index of wildfire ignition probability (WIPI) and wildfire spreading capacity (WSCI). Originally, both indexing methods rely on a multi-criteria evaluation which considers simultaneously the geophysical, hydrometeorological and anthropogenic factors of the territory. All stages of the process are performed by utilizing QGIS software. First, the forest surfaces within the metropolitan zone of Tirana (AL) and Sarajevo (BH) are extracted from Urban Atlas land cover data being provided as an open source by Copernicus data portal (EU). Reference points grid (distance of 100m) overlapping with the forest surfaces serve as pivot points to which the relative values of each criteria are projected. Later the absolute values are normalized into 10 classes via Jenks natural break method. The class value of each criterion is introduced into the indexing equation multiplied by the unique impact factor being weighted via pairwise comparative method in Analytical Hierarchy processing. The majority of the workflow steps are automated via Graphical Modeler in QGIS utilizing open source spatial data, giving floor to further applicability of the method to similar cases. As a result, there are produced statistical and graphical information being useful for identifying wildfire prone forest surfaces within the metropolitan areas. Being applied into two different study areas, the results enable a comparative discussion and evaluation at regional scale. By utilizing open source software and data, this work contributes in the development of practical and re-applicable models of wildfire risk assessment promoting open access scientific culture. Finally, the study results successful in testing a rapid and cost free method for identifying the forest areas prone to wildfire ignition and spreading risk in metropolitan areas in support to disaster risk reduction agendas and sustainable Development Goals.

Yohan Fayet, Virginie Chasles, Françoise Ducimetière et al.

Cancers inequalities in France are among the highest in developed countries and these gaps seem to be growing in the last decades. Territorial inequalities of cancers are analyzed by mapping, which showed higher mortality rates in the North-East Regions of France. At the local scale, standardized mortality rates are two times higher in some areas in the North as other areas in the South-East. Epidemiological studies, mostly based on multilevel analysis, evidence the impact of physical environment, deprivation or health care access on health outcomes. But to identify contextual effects are not sufficient to understand how cancer inequalities are built and how patient’s life context contributes to this process. As epidemiological approach is splitting contextual effects according to health outcomes, geographical approach may have to explain how these contextual effects lead to cancer inequalities, by using territorial typology to summarize these contextual effects. Comparing health outcomes according to this territorial classification may help to understand territory’s ability to generate health inequalities. Several stages across the cancer continuum are implied in the building of the cancer inequalities. This medical process has to be reconstructed to determine whether mortality inequalities are generated by a higher incidence or a lower survival. Moreover, lower survival may be linked to the worse prognosis of patients at diagnosis or to the lower quality of management according to cancer care facilities. Evolution of patients’ prognosis may be reconstructed, thanks to clinical data, in order to identify the most influent steps during this medical process. As a result, to understand the way geographical inequalities of cancers are building requires a multidisciplinary methodology, considering the territory’s contribution as a whole and using longitudinal clinical data. But to reconstitute this medical process is quite difficult actually because few longitudinal and exhaustive data are available. The EMS cohort represents an opportunity to test and discuss this methodological approach. This cohort includes all sarcoma (rare cancer) patients diagnosed in 2005 and 2006, in the Rhône-Alpes Region, and collects clinical data from the diagnosis to the patient follow-up. For this geographical analysis of the EMS cohort, we used a territorial typology generated thanks to multivariate analysis of 15 geographical variables known for their impact on health. Strong differences are noticed in terms of environment exposures, deprivation and health care access between the six types of territory (metropolitan neighborhoods, working-class neighborhoods, urban districts, residential areas, periurban areas, rural areas). This typology seems to be relevant to study geographical inequalities because it enables to distinguish populations which are not exposed to the same risks through their life context. A logistic regression including stage, age and histological subtype, as clinical factors influencing prognosis, estimates the patients’ prognosis at diagnosis. This prognosis score seems to be quite predictive because only 7% of “good prognosis” patients will be dead five years later, whereas this five years death rate raises to 80% for the worse prognosis patients. Analysis of geographical inequalities for sarcoma patients in the Rhône-Alpes Region shows the diversity of situations leading to inequalities of mortality. Indeed, the higher mortality in three types of territories has to be attributed to three different processes. In the case of the urban hub, this high mortality is linked to the higher incidence of sarcoma, as survival rate for patients of these districts is very close to the regional average. As incidence and prognosis risk in the working-class neighborhoods are quite similar to the regional average, higher mortality is due to the loss of survival odds in the course of treatments, probably because of a less optimal management. Despite the second lower incidence among the six types of territories, the worse prognosis of patients (more late-stage diagnosis) and the loss of survival odds during cancer management explained the high mortality rated in the rural areas. Thanks to the EMS cohort’s analysis, we assess the potential of a multidisciplinary methodology studying the territory’s ability to generate geographical inequalities of cancers. Territorial typology, produced without health outcomes data, may be used for every health studies as a synthetic index of the territory and also evidence strong inequalities of health according to people’s life contexts. As public policies struggle to be successful on this issue, to identify key events in the medical process leading to cancer inequalities may improve the territorialization and the efficiency of these policies. Territories with high risk before diagnosis would be focused on prevention and early diagnosis, whereas those more disadvantage during the management would lean towards cancer care quality, access to hospitals and cancer expertise and patient compliance.

Yuriy V. Pavlov

Research purpose. In order to implement the optimal metropolitan governance model, it is important to understand the conditions under which this or that model is economically effective. There is a need to develop a quantitatively justified methodology for choosing the optimal metropolitan governance model for different types of metropolitan areas. It has been emphasized in some federal documents of Russia, for example, in the “Recommendations for the selection of pilot projects for approbation and improvement of mechanisms for managing the development of metropolitan areas in the Russian Federation”.Materials and methods. Domestic researchers (N. Zubarevich, K. Gonchar, etc.) and foreign researchers (Glaeser Edward L., Nakamura, Ciccone A., Hall R., etc.) carried out the study of quantitative relationships between the economic growth of cities and the characteristics of cities.However, for metropolitan areas, the analysis of the relationship has not yet been implemented between the outpacing economic growth of the metropolitan area relative to the average country values (labor productivity and GDP per capita), the institutional factor (the type of metropolitan governance model), andthe non-institutional factor (population size). To identify the dependencies we are interested in, we used the OECD statistical database and OECD researches to identify the metropolitan governance model in the sample of metropolitan areas in the world. The sample in this research was 87 metropolitan areas in Europe and was divided into groups, depending on the population and the introduced metropolitan governance model. For each group, a correlation-regression analysis was performed and a weighted average was calculated from the indexes of the economic growth. As the leading index of the economic growth, labor productivity was used, as the final - GDP per capita. Then a comparison was made between the real value of economic growth in each surveyed metropolitan area and the expected value when implementing different metropolitan governance model. If the comparison showed the non-optimality of the implemented model for some index of the economic growth, then the values of the economic growth in the metropolitan area and the national average were compared. As a result, a recommendationwas given for the metropolitan area on the degree of need for the management reform and an optimal metropolitan governance model was selected.Results. Based on the revealed regularities, we have created a methodical approach to choose the optimal model of metropolitan governance according to the population size. It can be used as a tool to justify metropolitan governance reform. The advantage of the approach is the use of real quantitative data that reduces the degree of subjectivity in decision-making Conclusion. The methodical approach is tested on the example of eightmetropolitan areas (Lublin, Palermo, Krakow, Paris, Stuttgart, Madrid, Geneva, and Linz). It was revealed that there is no metropolitan governance model, which is always more efficient for all objects. As the result of the analysis for Geneva, the degree of need for management reforms was described as “high” with a recommendation for a transition to a decentralized metropolitan governance model. For Linz, Stuttgart and Madrid, the degree of need for reform is characterized as “low” with a recommendation for a transition to decentralization (Stuttgart) and centralization (Linz and Madrid). The rest of the metropolitan areas of the sample do not need reforms.

Valérie Jousseaume, Magali Talandier

This paper develops a methodological reflection on urban framework. Based on a extensive bibliography, it aims to define notions used in urban studies and point out pertinent indicators to identify different urban levels. We propose to generalize across metropolitan France, a method developed in western France in the framework of the research program of the UMR ESO called DYTEFORT (Dynamics and territorial land in rural areas in transition from Grand West of France). This allows us to list and cartography functional urban hierarchy in France. It defines and characterizes the rural / urban split line current. It shows the reversal of the demographic dynamics of the French urban hierarchy for 60 years. Finally, this work highlights the lack of tool to analyze the poles in suburban areas.

J. Anhorn, B. Khazai

In an emergency situation shelter space is crucial for people affected by natural hazards. Emergency planners in disaster relief and mass care can greatly benefit from a sound methodology that identifies suitable shelter areas and sites where shelter services need to be improved. A methodology to rank suitability of open spaces for contingency planning and placement of shelter in the immediate aftermath of a disaster is introduced. The Open Space Suitability Index uses the combination of two different measures: a qualitative evaluation criterion for the suitability and manageability of open spaces to be used as shelter sites and another quantitative criterion using a capacitated accessibility analysis based on network analysis. For the qualitative assessment implementation issues, environmental considerations and basic utility supply are the main categories to rank candidate shelter sites. A geographic information system is used to reveal spatial patterns of shelter demand. Advantages and limitations of this method are discussed on the basis of an earthquake hazard case study in the Kathmandu Metropolitan City. According to the results, out of 410 open spaces under investigation, 12.2% have to be considered not suitable (Category D and E) while 10.7% are Category A and 17.6% are Category B. Almost two-thirds (59.55%) are fairly suitable (Category C).

Lara P Clark, Dylan B Millet, Julian D Marshall

We describe spatial patterns in environmental injustice and inequality for residential outdoor nitrogen dioxide (NO2) concentrations in the contiguous United States. Our approach employs Census demographic data and a recently published high-resolution dataset of outdoor NO2 concentrations. Nationally, population-weighted mean NO2 concentrations are 4.6 ppb (38%, p<0.01) higher for nonwhites than for whites. The environmental health implications of that concentration disparity are compelling. For example, we estimate that reducing nonwhites' NO2 concentrations to levels experienced by whites would reduce Ischemic Heart Disease (IHD) mortality by ∼7,000 deaths per year, which is equivalent to 16 million people increasing their physical activity level from inactive (0 hours/week of physical activity) to sufficiently active (>2.5 hours/week of physical activity). Inequality for NO2 concentration is greater than inequality for income (Atkinson Index: 0.11 versus 0.08). Low-income nonwhite young children and elderly people are disproportionately exposed to residential outdoor NO2. Our findings establish a national context for previous work that has documented air pollution environmental injustice and inequality within individual US metropolitan areas and regions. Results given here can aid policy-makers in identifying locations with high environmental injustice and inequality. For example, states with both high injustice and high inequality (top quintile) for outdoor residential NO2 include New York, Michigan, and Wisconsin.

Arie Romein, Otto Verkoren, Ana María Fernandez

Since the mid 20th century, large urban areas in advanced economies have experienced a fundamental transformation from relatively compact monocentric cities towards more extended polycentric metropolitan areas. By now, it is being commented repeatedly, but not investigated systematically that the concept of polycentricity is also adequate to characterise recent metropolitan dynamics in Latin-America. This paper aims to present a few key-issues for a future research agenda into polycentricity in Latin-American metropolitan areas. These elements are identified from a review of existing literature. Since no clear-cut definition and operationalisation of polycentricity exist yet, we distinguish some key-elements of this phenomenon in North America as a frame of reference for this review. It reveals that ‘polycentricity U.S. style’ is at best dawning in Latin-America. In order to achieve a more appropriate picture of polycentricity of Latin American metropolitan areas, our ideas for a research agenda take into account these areas typical economic, social and spatial conditions.

Herbert Schubert

Taking as an example the situation pertaining in Lower Saxony between 1992 and 1997 regarding the designation of land for residential developments, this article shows that in particular outside urban regions and on the fringes of rural regions the consumption of land for settlement purposes is taking place in an uncoordinated fashion. Consequently, in the century before us we can look forward to a continuation of the desuburbanisation process in urban regions. The effect of this is that rural areas now need to promote co-operative, network-based and process-orientated procedural models of regional planning. These will allow us to establish to what extent the municipalities in rural regions are pursuing the principle of poly-centric concentration and are displaying an orientation towards a mid-ranking regional centre, or are choosing for orientation the metropolitan centres of more distant urban regions.  

Maria José Chinelatto Pinheiro Alves, Luiz Carlos Barradas Barata, Rita de Cássia Barradas Barata et al.

Com o objetivo de conhecer o perfil sócio-econômico dos indivíduos que se deslocaram das áreas endêmicas de malária do país, foram estudadas 566 pessoas com suspeita de malária que procuraram a confirmação diagnostica no Laboratório de Malária da Região Metropolitana de São Paulo da Superintendência de Controle de Endemias (SUCEN). As informações foram obtidas através da aplicação de formulário, no período de novembro de 1986 a junho de 1987. Da população estudada, 345 (61,0%) residiam na área endêmica, 479 (84,6%) eram do sexo masculino, 513 (90,7%) estavam na faixa etária de 15 a 55 anos e 307 (54,2%) apresentaram hemoscopia positiva para plasmódio. Com relação à ocupação na área de transmissão, observou-se que 109 (19,3%) estavam ligados a atividade de extração de minerais, 74 (13,2%) à agricultura e 46 (8,1%) à atividade de transporte. A análise da escolaridade mostrou que 486 (85,9%) tinham 1° ou 2° grau. Quanto ao conhecimento sobre a doença, 384 (67,8%) declararam pelo menos 1 malária anterior e 491 (86,8%) associavam à doença a presença do vetor. Dentre os 221 indivíduos residentes em São Paulo, 207 (93,7%) conheciam o risco de contrair malária por ocasião do deslocamento para área de transmissão. Daqueles residentes na área endêmica, 336 (97,4%) tinham conhecimento do risco de contrair a doença naquela região. O intervalo transcorrido entre os primeiros sintomas e a procura de atendimento médico em 386 (68,2%) indivíduos variou de 0 a 3 dias. As freqüências das variáveis estudadas mostraram de acordo com o resultado hemoscópico e o local da residência, diferenças estatísticas relevantes.<br>With a view to discovering the social and economic characteristics of people from endemic malarial areas of Brazil, 566 suspected malaria cases were studied at the S. Paulo City Metropolitan Region Malaria Laboratory. Data were obtained by means of the application of standardized questionnaires over the period from November 1986 to June 1987 to individuals with as history of transit to Brazil's endemic malarial region. Of the population studied, 345 (61.0%) lived in the endemic area; 479 (84.6%) were males, 513 (90.7%) were between 15 and 55 years old and 307 (54.2%) presented positive plasmodium haemoscopia. The analysis by educational level indicated that 486 (85.9%) had primary or secondary education; 109 (19.3%) worked in mineral extraction; 74 (13.2%) were farmers, and 46 (8.1%) were related to terrestrial transportation activities. With respect, to knowledge of the disease, 384 (67.8%) had at least 1 bout of malaria before and 491 (86.8%) associated the disease with the presence of the vector. Of the 221 residents in S. Paulo, 207 (93.7%), as well as 336 (97.4%) of those residing in the endemic area already know of the riscks of infection prior to travelling through the area of transmission. The interval between the first symptoms and the seeking for medical care varied from 0 to 3 days in 386 cases (68.2%). The frequencies of the variables studied analysed according to the haemoscopic result and the place of residence, were statistically significant.