The persistence of ancient settlements and urban sustainability.

We propose a dedicated research effort on the determinants of settlement persistence in the ancient world, with the potential to significantly advance the scientific understanding of urban sustainability today. Settlements (cities, towns, villages) are locations with two key attributes: They frame human interactions and activities in space, and they are where people dwell or live. Sustainability, in this case, focuses on the capacity of structures and functions of a settlement system (geography, demography, institutions) to provide for continuity of safe habitation. The 7,000-y-old experience of urbanism, as revealed by archaeology and history, includes many instances of settlements and settlement systems enduring, adapting to, or generating environmental, institutional, and technological changes. The field of urban sustainability lacks a firm scientific foundation for understanding the long durée, relying instead on narratives of collapse informed by limited case studies. We argue for the development of a new interdisciplinary research effort to establish scientific understanding of settlement and settlement system persistence. Such an effort would build upon the many fields that study human settlements to develop new theories and databases from the extensive documentation of ancient and premodern urban systems. A scientific foundation will generate novel insights to advance the field of urban sustainability.

Identification of urban land use efficiency by indicator-SDG 11.3.1.

Inefficiency in urban land use is one of the problems caused by rapid urbanization. The UN Sustainable Development Goals (SDGs) indicator 11.3.1 is designed to test urban land use efficiency. This study employed geospatial and statistical data to compute land use efficiencies from 1990 to 2015 with five 5-year and ten 15-year intervals in Wukang, center of Deqing County, China. A flowchart was designed to extract the built-up lands from multiple data sources. The produced built-up lands were demonstrated to provide good accuracy by constructing an error matrix between the extracted and manually interpreted built-up lands as classified and reference images, respectively. By using the model provided by UN metadata to calculate SDG 11.3.1, the land use efficiencies from 1990 to 2015 were identified in Wukang. Our results indicate that the land use efficiency in Deqing County center is lower than the average of cities around the world, primarily because our in-situ study focused on a county center with larger rural regions than urban areas. Over the long term, urban land use becomes denser as the population grows, which will have a positive impact on the sustainability of urban development. This work is helpful for the local government to balance urban land consumption and population growth.

Research on the relationship between Urban economic development level and urban spatial structure-A case study of two Chinese cities.

The characteristics of urban spatial structure and the objective evaluation of the development level of urban economy have always been the concern of urban researchers, However, the spatial relationship between urban spatial structure and urban economic development level is often deliberately ignored. Through the point of interest (POI), the identification framework is constructed, the spatial structure of the city is identified and evaluated, and the Geographically Weighted Regression analysis is carried out with the distribution of unit GDP (Gross Domestic Product) in this study. The research shows that Kunming and Guiyang are polycentric spatial structures and Kunming's structure is more significant. Kunming's economic level is generally higher than Guiyang, but the unit area cannot be compared. The city center will promote the development of the central area in this city, and the more urban centers are distributed within the geographical and spatial range, the greater contribution would have to economic development. In addition, the results of this study will have a positive impact on urban planning and construction, and will also provide a new perspective for the study of cities and related disciplines.

Using morphological attributes for the fast assessment of nutritional responses of Buddhist pine (Podocarpus macrophyllus [Thunb.] D. Don) seedlings to exponential fertilization.

Culturing slowly growing tree seedlings is a potential approach for managing the conflict between the increasing demand for ornamental stock and the decreasing area of farmlands due to urbanization. In this study, Buddhist pine (Podocarpus macrophyllus [Thunb.] D. Don) seedlings were raised in multishelves with light-emitting diode lighting in the spectrum of 17:75:8 (red:green:blue) at 190-320 µmol m-2 s-1 with controlled temperature and relative humidity at 19.5°C and 60%, respectively. Seedlings were fed by exponential fertilization (EF) (nitrogen [N]-phosphorus [P]2O5-K2O, 10-7-9) at eight rates of 0 (control), 20 (E20), 40 (E40), 60 (E60), 80 (E80), 100 (E100), 120 (E120), and 140 (E140) mg N seedling-1 for four months through 16 fertilizer applications. The nutritional responses of Buddhist pine seedlings can be identified and classified into various stages in response to increasing doses, up to and over 120 N seedling-1. Morphological traits, i.e., the green color index and leaf area (LA) obtained by digital analysis and the fine root growth, all remained constant in response to doses that induced steady nutrient loading. LA had a positive relationship with most of the nutritional parameters. A dose range between 60 and 120 mg N seedling-1 was recommended for the culture of Buddhist pine seedlings. At this range of fertilizer doses, measuring the leaf area through digital scanning can easily and rapidly indicate the inherent nutrient status of the seedlings.

Vegetation communities on commercial developments are heterogenous and determined by development and landscaping decisions, not socioeconomics.

In urban ecosystems, woody vegetation communities and the ecosystem functions and habitat they provide are largely controlled by humans. These communities are assembled during development, landscaping, and maintenance processes according to decisions made by human actors. While vegetation communities on residential land uses are increasingly well studied, these efforts generally have not extended to other land uses, including commercial property. To fill this gap, I surveyed tree and shrub communities on office developments located in Redmond and Bellevue, Washington, USA, and explored whether aggregated neighborhood and parcel scale socio-economic variables or variables describing the outcome of development and landscaping actions better explained variation in vegetation communities. I found that both tree and shrub communities on office developments are heterogenous, with sites characterized by native or ornamental vegetation. The heterogeneity I observed in vegetation communities within one land use suggests that different ecosystem functions, habitat quality, and habitat quantities are provided on office developments. Greater provision of e.g. native conifer habitat is possible using currently existing developments as models. Additionally, the outcome of development and landscaping decisions explained more variation in community composition than the socio-economic factors found significant on residential property. Together with previous research showing that residential property owner attitudes and actions are more important than socio-economic descriptors, my results suggest that individual motivators, including intended audience, may be the primary determinant of urban vegetation communities. Future urban ecology research should consider sampling the vegetation gradient within land uses, better understanding individual motivation for vegetation management, and creating models of the urban ecosystems that account for alternate decision pathways on different land uses.

Health Benefits of Physical Activity Related to an Urban Riverside Regeneration.

The promotion of physical activity through better urban design is one pathway by which health and well-being improvements can be achieved. This study aimed to quantify health and health-related economic impacts associated with physical activity in an urban riverside park regeneration project in Barcelona, Spain. We used data from Barcelona local authorities and meta-analysis assessing physical activity and health outcomes to develop and apply the "Blue Active Tool". We estimated park user health impacts in terms of all-cause mortality, morbidity (ischemic heart disease; ischemic stroke; type 2 diabetes; cancers of the colon and breast; and dementia), disability-adjusted life years (DALYs) and health-related economic impacts. We estimated that 5753 adult users visited the riverside park daily and performed different types of physical activity (walking for leisure or to/from work, cycling, and running). Related to the physical activity conducted on the riverside park, we estimated an annual reduction of 7.3 deaths (95% CI: 5.4; 10.2), and 6.2 cases of diseases (95% CI: 2.0; 11.6). This corresponds to 11.9 DALYs (95% CI: 3.4; 20.5) and an annual health-economic impact of 23.4 million euros (95% CI: 17.2 million; 32.8 million). The urban regeneration intervention of this riverside park provides health and health-related economic benefits to the population using the infrastructure.

Mortality from Homicides in Slums in the City of Belo Horizonte, Brazil: An Evaluation of the Impact of a Re-Urbanization Project.

Background: Homicide rates in Brazil are among the highest worldwide. Although not exclusive to large Brazilian cities, homicides find their most important determinants in cities' slums. In the last decade, an urban renewal process has been initiated in the city of Belo Horizonte, in Brazil. Named Vila Viva project, it includes structuring urban interventions such as urban renewal, social development actions and land regularization in the slums of the city. This study evaluates the project's effect on homicide rates according to time and interventions. Methods: Homicide rates were analyzed comparing five slums with interventions (S1⁻S5) to five grouped non-intervened slums (S0), with similar socioeconomic characteristics from 2002 to 2012. Poisson regression model estimates the effect of time of observation and the effect of time of exposure (in years) to a completed intervention, besides the overall risk ratio (RR). Results: Using the time of observation in years, homicide rates decreased in the studied period and even more if considered cumulative time of exposure to a completed intervention for S1, S2, S3 and S4, but not for S5. Conclusions: Although the results of the effect of the interventions are not repeated in all slums, a downward trend in homicide rates has been found, which is connected to the interventions. New approaches could be necessary in order to verify the nexus between slum renewal projects and the reduction of homicide rates.

Urban renewal, gentrification and health equity: a realist perspective.

Background: Up to now, research has focused on the effects of urban renewal programs and their impacts on health. While some of this research points to potential negative health effects due to gentrification, evidence that addresses the complexity associated with this relation is much needed. This paper seeks to better understand when, why and how health inequities arise from urban renewal interventions resulting in gentrification. Methods: A realist review, a qualitative systematic review method, aimed to better explain the relation between context, mechanism and outcomes, was used. A literature search was done to identify theoretical models of how urban renewal programs can result in gentrification, which in turn could have negative impacts on health. A systematic approach was then used to identify peer-reviewed studies that provided evidence to support or refute the initial assumptions. Results: Urban renewal programs that resulted in gentrification tended to have negative health effects primarily in residents that were low-income. Urban renewal policies that were inclusive of populations that are vulnerable, from the beginning were less likely to result in gentrification and more likely to positively impact health through physical and social improvements. Conclusions: Research has shown urban renewal policies have significant impacts on populations that are vulnerable and those that result in gentrification can result in negative health consequences for this population. A better understanding of this is needed to impact future policies and advocate for a community-participatory model that includes such populations in the early planning stages.

Characteristics and use of urban health indicator tools by municipal built environment policy and decision-makers: a systematic review protocol.

BACKGROUND: There is wide agreement that there is a lack of attention to health in municipal environmental policy-making, such as urban planning and regeneration. Explanations for this include differing professional norms between health and urban environment professionals, system complexity and limited evidence for causality between attributes of the built environment and health outcomes. Data from urban health indicator (UHI) tools are potentially a valuable form of evidence for local government policy and decision-makers. Although many UHI tools have been specifically developed to inform policy, there is poor understanding of how they are used. This study aims to identify the nature and characteristics of UHI tools and their use by municipal built environment policy and decision-makers. METHODS: Health and social sciences databases (ASSIA, Campbell Library, EMBASE, MEDLINE, Scopus, Social Policy and Practice and Web of Science Core Collection) will be searched for studies using UHI tools alongside hand-searching of key journals and citation searches of included studies. Advanced searches of practitioner websites and Google will also be used to find grey literature. Search results will be screened for UHI tools, and for studies which report on or evaluate the use of such tools. Data about UHI tools will be extracted to compile a census and taxonomy of existing tools based on their specific characteristics and purpose. In addition, qualitative and quantitative studies about the use of these tools will be appraised using quality appraisal tools produced by the UK National Institute for Health and Care Excellence (NICE) and synthesised in order to gain insight into the perceptions, value and use of UHI tools in the municipal built environment policy and decision-making process. This review is not registered with PROSPERO. DISCUSSION: This systematic review focuses specifically on UHI tools that assess the physical environment's impact on health (such as transport, housing, air quality and greenspace). This study will help indicator producers understand whether this form of evidence is of value to built environment policy and decision-makers and how such tools should be tailored for this audience. SYSTEMATIC REVIEW REGISTRATION: N/A.

Urban sustainability in an age of enduring inequalities: Advancing theory and ecometrics for the 21st-century city.

The environmental fragility of cities under advanced urbanization has motivated extensive efforts to promote the sustainability of urban ecosystems and physical infrastructures. Less attention has been devoted to neighborhood inequalities and fissures in the civic infrastructure that potentially challenge social sustainability and the capacity of cities to collectively address environmental challenges. This article draws on a program of research in three American cities-Boston, Chicago, and Los Angeles-to develop hypotheses and methodological strategies for assessing how the multidimensional and multilevel inequalities that characterize contemporary cities bear on sustainability. In addition to standard concerns with relative inequality in income, the article reviews evidence on compounded deprivation, racial cleavages, civic engagement, institutional cynicism, and segregated patterns of urban mobility and organizational ties that differentially connect neighborhood resources. Harnessing "ecometric" measurement tools and emerging sources of urban data with a theoretically guided framework on neighborhood inequality can enhance the pursuit of sustainable cities, both in the United States and globally.

Urban upgrading and its impact on health: a "quasi-experimental" mixed-methods study protocol for the BH-Viva Project.

There is little scientific evidence that urban upgrading helps improve health or reduce inequities. This article presents the design for the BH-Viva Project, a "quasi-experimental", multiphase, mixed-methods study with quantitative and qualitative components, proposing an analytical model for monitoring the effects that interventions in the urban environment can have on residents' health in slums in Belo Horizonte, Minas Gerais State, Brazil. A preliminary analysis revealed intra-urban differences in age-specific mortality when comparing areas with and without interventions; the mortality rate from 2002 to 2012 was stable in the "formal city", increased in slums without interventions, and decreased in slums with interventions. BH-Viva represents an effort at advancing methodological issues, providing learning and theoretical backing for urban health research and research methods, allowing their application and extension to other urban contexts.

Urban upgrading and its impact on health: a “quasi-experimental” mixed-methods study protocol for the BH-Viva Project / Intervenciones de renovación urbana y el impacto en la salud: protocolo de un estudio cuasi-experimental con métodos mixtos – Proyecto BH-Viva / Intervenções de requalificação urbana e o impacto na saúde: protocolo de estudo “quasi-experimental” com métodos mistos – Projeto BH-Viva

Abstract There is little scientific evidence that urban upgrading helps improve health or reduce inequities. This article presents the design for the BH-Viva Project, a “quasi-experimental”, multiphase, mixed-methods study with quantitative and qualitative components, proposing an analytical model for monitoring the effects that interventions in the urban environment can have on residents’ health in slums in Belo Horizonte, Minas Gerais State, Brazil. A preliminary analysis revealed intra-urban differences in age-specific mortality when comparing areas with and without interventions; the mortality rate from 2002 to 2012 was stable in the “formal city”, increased in slums without interventions, and decreased in slums with interventions. BH-Viva represents an effort at advancing methodological issues, providing learning and theoretical backing for urban health research and research methods, allowing their application and extension to other urban contexts.

Resumen Hay poca evidencia científica de que las estrategias de regeneración urbana contribuyen a mejorar la salud y reducir las inequidades. En este trabajo se presenta el diseño del Proyecto BH-Viva, estudio “cuasi-experimental”, de múltiples fases, con métodos mixtos, incluidos los componentes cuantitativos y cualitativos, que propone un modelo de análisis para el seguimiento de los efectos de las intervenciones en el entorno urbano puede tener en la salud residentes de las aldeas y los barrios marginales en Belo Horizonte, Minas Gerais, Brasil. En el análisis preliminar hubo diferencias intra-urbanas en la mortalidad proporcional por grupos de edad, al comparar las zonas con y sin la intervención; las tendencias de la mortalidad de 2002 hasta 2012 se mantuvieron estables en la ciudad formal, el aumento en el pueblo sin ninguna intervención y disminuyen de que con la intervención. El BH-Viva es un esfuerzo para avanzar en cuestiones metodológicas, proporcionando el aprendizaje y la base teórica de los métodos de investigación y de investigación en salud urbana, lo que permite la aplicación y la extensión en otros contextos urbanos.

Resumo Há poucas evidências científicas de que estratégias de requalificação urbana contribuam para a melhoria da saúde e redução das iniquidades. Este artigo apresenta o delineamento do Projeto BH-Viva – estudo “quasi-experimental”, multifásico, com métodos mistos, incluindo componentes quantitativos e qualitativos, propondo um modelo de análise para monitoramento dos efeitos que intervenções no ambiente urbano possam ter sobre a saúde de moradores de vilas e favelas em Belo Horizonte, Minas Gerais, Brasil. Em análise preliminar observou-se diferenças intraurbanas na mortalidade proporcional por grupos etários, ao comparar áreas com e sem intervenção; a tendência de mortalidade de 2002 a 2012 mostrou estabilidade na cidade formal, aumento na vila sem intervenção e decréscimo naquela com intervenção. BH-Viva representa um esforço no avanço de questões metodológicas, fornecendo aprendizado e subsídios teóricos para a pesquisa e métodos de investigação em Saúde Urbana, possibilitando a aplicação e extensão em outros contextos urbanos.

Nonzero-Sum Relationships in Mitigating Urban Carbon Emissions: A Dynamic Network Simulation.

The "stove-pipe" way of thinking has been mostly used in mitigating carbon emissions and managing socioeconomics because of its convenience of implementation. However, systems-oriented approaches become imperative in pursuit of an efficient regulation of carbon emissions from systems as complicated as urban systems. The aim of this paper is to establish a dynamic network approach that is capable of assessing the effectiveness of carbon emissions mitigation in a more holistic way. A carbon metabolic network is constructed by modeling the carbon flows between economic sectors and environment. With the network shocked by interventions to the sectoral carbon flows, indirect emissions from the city are accounted for under certain carbon mitigation strategies. The nonzero-sum relationships between sectors and environmental components are identified based on utility analysis, which synthesize the nature of direct and indirect network interactions. The results of the case study of Beijing suggest that the stove-pipe mitigation strategies targeted the economic sectors might be not as efficient as they were expected. A direct cutting in material or energy import to the sectors may result in a rebound in indirect emissions and thus fails to achieve the carbon mitigation goal of the city as a whole. A promising way of foreseeing the dynamic mechanism of emissions is to analyze the nonzero-sum relationships between important urban components. Thinking cities as systems of interactions, the network approach is potentially a strong tool for appraising and filtering mitigation strategies of carbon emissions.

Valuing the benefits of creek rehabilitation: building a business case for public investments in urban green infrastructure.

In an effort to increase the livability of its cities, public agencies in Australia are investing in green infrastructure to improve public health, reduce heat island effects and transition toward water sensitive urban design. In this paper, we present a simple and replicable approach to building a business case for green infrastructure. This approach requires much less time and resources compared to other methods for estimating the social and economic returns to society from such investments. It is a pragmatic, reasonably comprehensive approach that includes socio-demographic profile of potential users and catchment analysis to assess the economic value of community benefits of the investment. The approach has been applied to a case study area in the City of Brimbank, a western suburb of Greater Melbourne. We find that subject to a set of assumptions, a reasonable business case can be made. We estimate potential public benefits of avoided health costs of about AU$75,049 per annum and potential private benefits of AU$3.9 million. The project area is one of the most poorly serviced areas in the municipality in terms of quality open spaces and the potential beneficiaries are from relatively low income households with less than average health status and education levels. The values of cultural (recreational benefits, avoided health costs, and increased property values) and regulating (reduction in heat island effect and carbon sequestration) ecosystem services were quantified that can potentially offset annual maintenance costs.

Exploring complex causal pathways between urban renewal, health and health inequality using a theory-driven realist approach.

INTRODUCTION: Urban populations are growing and to accommodate these numbers, cities are becoming more involved in urban renewal programs to improve the physical, social and economic conditions in different areas. This paper explores some of the complexities surrounding the link between urban renewal, health and health inequalities using a theory-driven approach. METHODS: We focus on an urban renewal initiative implemented in Barcelona, the Neighbourhoods Law, targeting Barcelona's (Spain) most deprived neighbourhoods. We present evidence from two studies on the health evaluation of the Neighbourhoods Law, while drawing from recent urban renewal literature, to follow a four-step process to develop a program theory. We then use two specific urban renewal interventions, the construction of a large central plaza and the repair of streets and sidewalks, to further examine this link. DISCUSSION: In order for urban renewal programs to affect health and health inequality, neighbours must use and adapt to the changes produced by the intervention. However, there exist barriers that can result in negative outcomes including factors such as accessibility, safety and security. CONCLUSION: This paper provides a different perspective to the field that is largely dominated by traditional quantitative studies that are not always able to address the complexities such interventions provide. Furthermore, the framework and discussions serve as a guide for future research, policy development and evaluation.

The effect of urban green on small-area (healthy) life expectancy.

BACKGROUND: Several epidemiological studies have investigated the effect of the quantity of green space on health outcomes such as self-rated health, morbidity and mortality ratios. These studies have consistently found positive associations between the quantity of green and health. However, the impact of other aspects, such as the perceived quality and average distance to public green, and the effect of urban green on population health are still largely unknown. METHODS: Linear regression models were used to investigate the impact of three different measures of urban green on small-area life expectancy (LE) and healthy life expectancy (HLE) in The Netherlands. All regressions corrected for average neighbourhood household income, accommodated spatial autocorrelation, and took measurement uncertainty of LE, HLE as well as the quality of urban green into account. RESULTS: Both the quantity and the perceived quality of urban green are modestly related to small-area LE and HLE: an increase of 1 SD in the percentage of urban green space is associated with a 0.1-year higher LE, and, in the case of quality of green, with an approximately 0.3-year higher LE and HLE. The average distance to the nearest public green is unrelated to population health. CONCLUSIONS: The quantity and particularly quality of urban green are positively associated with small-area LE and HLE. This concurs with a growing body of evidence that urban green reduces stress, stimulates physical activity, improves the microclimate and reduces ambient air pollution. Accordingly, urban green development deserves a more prominent place in urban regeneration and neighbourhood renewal programmes.

The evolution of the sustainability assessment tool SBToolPT: from buildings to the built environment.

This paper analyses the current trends in sustainability assessment. After about 15 years from the launch of sustainability assessment tools, focused on buildings evaluation, the paradigm of sustainability assessment tools is changing from the building scale to the built environment scale. Currently European cities and cities around the world are concerned with sustainable development, as well as its evolution. Cities seek a way to adapt to contemporary changes, in order to meet the required needs and ensure population's well-being. Considering this, the new generations of sustainability assessment tools are being developed to be used to guide and help cities and urban areas to become more sustainable. Following the trend of the most important sustainability assessment tools, the sustainability assessment tool SBTool(PT) is also developing its version for assessing the sustainability of the built environment, namely, the urban planning projects and the urban regeneration projects, to be developed in Portugal, the SBTool(PT)-UP. The application of the methodology to three case studies will demonstrate its feasibility; at the same time this will identify the best practices which will serve as reference for new projects, thereby assisting the development of the tool.

Position of social determinants of health in urban man-made lakes plans.

BACKGROUND AND OBJECTIVE: A social determinants approach proposes that enhancing living conditions in areas such as income, housing, transportation, employment, education, social support, and health services is central to improving the health of urban populations. Urban development projects can be costly but have health impacts. The benefit derived from the creation of man-made lakes in developing countries is usually associated with great risks; however, the evidence for physical and non-physical health benefits of urban man-made lake is unclear. The aim of this paper is to formulate a conceptual framework of associations between urban man-made lakes and social determinants of health. METHOD: This study was a qualitative study carried out using one focus group discussion and 16 individual interviews. Data were analyzed based on deductive-inductive content analysis approach. RESULTS: Participants' points of view were analyzed within 261 codes. Data analysis matrix was the conceptual framework of social determinants of health commission and its sub-groups, thus, two structural and mediating determinants categories as well as their sub-sets were created accordingly. In addition, some extra sub-sets including environment, air quality, weather changes, noise pollution, pathogenesis, quality of life, shortage of available resources, region popularity, ethnicity, tourism, social and physical development of children, unintentional injuries, aesthetic, and spirituality were extracted beyond the matrix factors, which were placed in each of above categories based on their thematic content. CONCLUSION: This paper has illustrated that the quality and type of man-made lake provided within communities can have a significant and sustained impact on community's health and wellbeing. Therefore, in order to strengthen positive effects and reduce negative effects of any developmental projects within community, their impacts on public health should be taken into consideration.

Use of impact fees to incentivize low-impact development and promote compact growth.

Low-impact development (LID) is an innovative stormwater management strategy that restores the predevelopment hydrology to prevent increased stormwater runoff from land development. Integrating LID into residential subdivisions and increasing population density by building more compact living spaces (e.g., apartment homes) can result in a more sustainable city by reducing stormwater runoff, saving infrastructural cost, increasing the number of affordable homes, and supporting public transportation. We develop an agent-based model (ABM) that describes the interactions between several decision-makers (i.e., local government, a developer, and homebuyers) and fiscal drivers (e.g., property taxes, impact fees). The model simulates the development of nine square miles of greenfield land. A more sustainable development (MSD) scenario introduces an impact fee that developers must pay if they choose not to use LID to build houses or apartment homes. Model simulations show homeowners selecting apartment homes 60% or 35% of the time after 30 years of development in MSD or business as usual (BAU) scenarios, respectively. The increased adoption of apartment homes results from the lower cost of using LID and improved quality of life for apartment homes relative to single-family homes. The MSD scenario generates more tax revenue and water savings than does BAU. A time-dependent global sensitivity analysis quantifies the importance of socioeconomic variables on the adoption rate of apartment homes. The top influential factors are the annual pay rates (or capital recovery factor) for single-family houses and apartment homes. The ABM can be used by city managers and policymakers for scenario exploration in accordance with local conditions to evaluate the effectiveness of impact fees and other policies in promoting LID and compact growth.

Slum upgrading strategies involving physical environment and infrastructure interventions and their effects on health and socio-economic outcomes.

BACKGROUND: Slums are densely populated, neglected parts of cities where housing and living conditions are exceptionally poor. In situ slum upgrading, at its basic level, involves improving the physical environment of the existing area, such as improving and installing basic infrastructure like water, sanitation, solid waste collection, electricity, storm water drainage, access roads and footpaths, and street lighting, as well as home improvements and securing land tenure. OBJECTIVES: To explore the effects of slum upgrading strategies involving physical environment and infrastructure interventions on the health, quality of life and socio-economic wellbeing of urban slum dwellers in low and middle income countries (LMIC). Where reported, data were collected on the perspectives of slum dwellers regarding their needs, preferences for and satisfaction with interventions received. SEARCH METHODS: We searched for published and unpublished studies in 28 bibliographic databases including multidisciplinary (for example Scopus) and specialist databases covering health, social science, urban planning, environment and LMIC topics. Snowballing techniques included searching websites, journal handsearching, contacting authors and reference list checking. Searches were not restricted by language or publication date. SELECTION CRITERIA: We included studies examining the impact of slum upgrading strategies involving physical environment or infrastructure improvements (with or without additional co-interventions) on the health, quality of life and socio-economic wellbeing of LMIC urban slum dwellers. Randomised controlled trials (RCTs), controlled before and after studies (CBAs) and interrupted time series (ITS) were eligible for the main analysis. Controlled studies with only post-intervention data (CPI) and uncontrolled before and after (UBA) studies were included in a separate narrative to examine consistency of results and to supplement evidence gaps in the main analysis. DATA COLLECTION AND ANALYSIS: Two authors independently extracted data and assessed risk of bias for each study. Differences between the included study interventions and outcomes precluded meta-analysis so the results were presented in a narrative summary with illustrative harvest plots. The body of evidence for outcomes within the main analysis was assessed according to GRADE as very low, low, moderate or high quality. MAIN RESULTS: We identified 10,488 unique records, with 323 screened as full text. Five studies were included for the main analysis: one RCT with a low risk, two CBAs with a moderate risk and two CBAs with a high risk of bias. Three CBAs evaluated multicomponent slum upgrading strategies. Road paving only was evaluated in one RCT and water supply in one CBA. A total of 3453 households or observations were included within the four studies reporting sample sizes.Most health outcomes in the main studies related to communicable diseases, for which the body of evidence was judged to be low quality. One CBA with a moderate risk of bias found that diarrhoeal incidence was reduced in households which received water connections from a private water company (risk ratio (RR) 0.53; 95% confidence interval (CI) 0.27 to 1.04) and the severity of diarrhoeal episodes (RR 0.48; 95% CI 0.19 to 1.22). There was no effect for duration of diarrhoea. Road paving did not result in changes in parasitic infections or sickness in one RCT. After multicomponent slum upgrading, claims for a waterborne disease as opposed to a non-waterborne disease reduced (RR 0.64; 95% CI 0.27 to 0.98) in one CBA with a high risk of bias but there was no change in sanitation-related mortality in a CBA with a moderate risk of bias.The majority of socio-economic outcomes reported within the main studies related to financial poverty, for which the body of evidence was of very low quality. Results were mixed amongst the main studies; one RCT and two CBAs reported no effect on the income of slum dwellers following slum upgrading. One further CBA found significant reduction in monthly water expenditure (mean difference (MD) -17.11 pesos; 95% CI -32.6 to -1.62). One RCT also showed mixed results for employment variables, finding no effect on unemployment levels but increased weekly worked hours (MD 4.68; 95% CI -0.46 to 9.82) and lower risk of residents intending to migrate for work (RR 0.78; 95% CI 0.60 to 1.01).There was no evidence available to assess the impact of slum upgrading on non-communicable diseases or social capital. Maternal and perinatal conditions, infant mortality, nutritional deficiencies, injuries, self-reported quality of life, education and crime were evaluated in one study each.Nine supporting studies were included that measured varying outcomes (6794 households or observations within eight studies reporting sample sizes). One CPI evaluated cement flooring only while three UBAs and five CPIs evaluated multicomponent slum upgrading strategies. All studies but one had a high risk of bias.The studies reinforced main study findings for diarrhoea incidence and water-related expenditure. Findings for parasitic infections and financial poverty were inconsistent with the main studies. In addition, supporting studies reported a number of disparate outcomes that were not evaluated in the main studies.Five supporting studies included some limited information on slum dweller perspectives. They indicated the importance of appropriate siting of facilities, preference for private facilities, delivering synergistic interventions together, and ensuring that infrastructure was fit for purpose and systems were provided for cleaning, maintenance and repair. AUTHORS' CONCLUSIONS: A high risk of bias within the included studies, heterogeneity and evidence gaps prevent firm conclusions on the effect of slum upgrading strategies on health and socio-economic wellbeing. The most common health and socio-economic outcomes reported were communicable diseases and indicators of financial poverty. There was a limited but consistent body of evidence to suggest that slum upgrading may reduce the incidence of diarrhoeal diseases and water-related expenditure. The information available on slum dwellers' perspectives provided some insight to barriers and facilitators for successful implementation and maintenance of interventions.The availability and use of reliable, comparable outcome measures to determine the effect of slum upgrading on health, quality of life and socio-economic wellbeing would make a useful contribution to new research in this important area. Given the complexity in delivering slum upgrading, evaluations should look to incorporate process and qualitative information alongside quantitative effectiveness data to determine which particular interventions work (or don't work) and for whom.