Promoting ecosystem and human health in urban areas using Green Infrastructure: A literature review
Ecosystem services provided by a Green Infrastructure can provide healthy environments and physical and psychological health benefits to the people residing within them. Healthy environments can contribute to improved socio-economic benefits for those communities as well.
Tzoulas, K., Korpela, K., Venn, S., Yli-Pelkonen, et al. (2007). Promoting ecosystem and human health in urban areas using Green Infrastructure: A literature review. Landscape and Urban Planning, 81(3), 167-178.
Europe is a highly urbanised continent. The consequent loss and degradation of urban and peri-urban green space could adversely affect ecosystems as well as human health and well-being. The aim of this paper is to formulate a conceptual framework of associations between urban green space, and ecosystem and human health. Through an interdisciplinary literature review the concepts of Green Infrastructure, ecosystem health, and human health and well-being are discussed. The possible contributions of urban and peri-urban green space systems, or Green Infrastructure, on both ecosystem and human health are critically reviewed. Finally, based on a synthesis of the literature a conceptual framework is presented. The proposed conceptual framework highlights many dynamic factors, and their complex interactions, affecting ecosystem health and human health in urban areas. This framework forms the context into which extant and new research can be placed. In this way it forms the basis for a new interdisciplinary research agenda. The United Nations (2001) estimated that the level of urbanisation in Europe will increase to almost 80% by 2015, compared to 75% in 2000. Urban growth, by altering cities and the surrounding countryside, presents numerous challenges for the maintenance of urban green space, and consequently also for human health and well-being. The link between an individual’s socio-economic position and their health is well-established (e.g. Bartley et al., 1997; Brunner, 1997; Davey-Smith et al., 1997, 1990). Furthermore, epidemiological studies have provided evidence of a positive relationship between longevity and access to green space (Takano et al., 2002; Tanaka et al., 1996), and between green space and self-reported health (de Vries et al., 2003). The World Health Organization defines human health as “a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity” (WHO, 1948). This definition implies that to fully understand and describe the concept of health a wide array of related factors ought to be considered including, amongst others, biological, psychological and social. Ecosystem health is generally defined as the occurrence of normal ecosystem processes and functions (Costanza, 1992). A healthy ecosystem is thought of as one that is free from distress and degradation, maintains its organisation and autonomy over time and is resilient to stress (Costanza, 1992; Mageau et al., 1995; Costanza et al., 1998; Rapport et al., 1998; Lu and Li, 2003). Some authors have pointed out that defining ecosystem health depends on human-social values and desires (Lackey, 1998; Brussard et al., 1998). Therefore, the concept of ecosystem health, like that of human health, integrates numerous ecological, social, economic and political factors. METHODOLOGY Electronic journal databases (i.e.Web of Knowledge, Science @ Direct and Infotrac—Health & Wellness Resource Centre) were first searched by journal name to identify journals in urban nature conservation, ecosystem health, environmental psychology and public health. At this stage only peer reviewed publications were selected for the subsequent selection of articles. The journals included in the literature review were Landscape and Urban Planning, The Journal of Environmental Psychology, Environment and Behaviour, Ecosystem Health, The British Medical Journal, and Preventative Medicine. Using the keywords of Green Infrastructure, ecosystem health, human health, well-being and conceptual models, relevant articles from these journals were identified. Additionally, landmark book publications where included in the literature review. The articles were critically evaluated by conducting a strengths and weaknesses analysis of the study design and interpretations. Since causal relationships between Green Infrastructure components and human health are difficult to establish and quantify this critical literature review covered studies that focussed on association rather than causation. BACKGROUND The literature reviewed revealed a number of themes and relationships that relate to Green Infrastructure, ecosystem health and human health. These themes and relationships were used to construct a conceptual framework. The themes were summarised and classified into seven thematic groups each one comprising a number of elements. Then, the dynamic nature of relationships between Green Infrastructure, ecosystem health and human health were illustrated. This was achieved by organising the themes and relationships, in the conceptual framework, according to associations that have been empirically evaluated by published studies. The concept of Green Infrastructure has been introduced to upgrade urban green space systems as a coherent planning entity Sandstr¨om (2002). It can be considered to comprise of all natural, semi-natural and artificial networks of multifunctional ecological systems within, around and between urban areas, at all spatial scales. The concept of Green Infrastructure emphasises the quality as well as quantity of urban and peri-urban green spaces (Turner, 1996; Rudlin and Falk, 1999), their multifunctional role (Sandstr¨om, 2002), and the importance of interconnections between habitats (van der Ryn and Cowan, 1996). If a Green Infrastructure is proactively planned, developed, and maintained it has the potential to guide urban development by providing a framework for economic growth and nature conservation (Walmsley, 2006; Schrijnen, 2000; van der Ryn and Cowan, 1996). Such a planned approachwould offer many opportunities for integration between urban development, nature conservation and public health promotion.
There is clearly a need to evaluate the potential economic implications of Green Infrastructure, linked to health effects and health service budgets. In a pioneering study, Bird (2004) developed a model for calculating health care savings attributable to increased outdoor physical activity. Based on a study of five major UK cities, he calculated that if 20% of the population within 2 km of an 8–20 ha green space used that space to reach a target of 30 min activity on 5 days a week, the saving to the UK’s National Health Service would be more than £1.8 million (D 2.7 million) a year. This finding makes a strong economic case, as well as a strong social case, for enhancing the urban Green Infrastructure for the purpose of reducing health care expenditure. If the concept of Green Infrastructure is to gain recognition as an important public health factor, it is necessary to articulate the link between ecological and social systems in a way that is understood by those working in different disciplines. The linkages between the Green Infrastructure, ecosystem and human health and well-being presented in this paper provide a basis for such an interdisciplinary “conceptual meeting point”. Urban planners, developers, politicians, urban ecologists, atmospheric and soil scientists and social scientists, will be familiar with aspects of the conceptual framework (Fig. 1). Also, public health professionals will not be strangers to issues relating to pollution, and to the issues included in boxes 4 and 6. Community health and psychological health issues are the remit of epidemiologists and environmental psychologists. Thus, this conceptual framework presents opportunities for interdisciplinary collaboration for studying the relationships between the Green Infrastructure and ecosystem and human health. Neither of the two concepts that are central to the conceptual framework (i.e. ecosystem and human health) can be precisely defined. The concept of human health is defined as an ideal state of socio-economic and biological being (WHO, 1948). Ecosystem health is seen as a heuristic metaphor based on the concept of human health (Haila, 1998). The framework proposed should facilitate interdisciplinary debate to define the conditions of public health and ecosystem health. Ecosystem health indicators based on habitat and species indicators, air and water quality and landscape features and form, can be developed from the top half of the conceptual framework. Public health indicators based on socio-economic derivation, physical illness, death rates, community participation and psychological disorders, can be developed based on the lower half of the conceptual framework. Thus, the conceptual framework (Fig. 1) illustrates possible ways for developing associations between the concepts of Green Infrastructure, ecosystem health and public health. This provides a basis for the establishment of an interdisciplinary approach to urban planning, as has been recommended in a number of studies (Berkes and Folke, 1998; Haeuber and Ringold, 1998; Collins et al., 2000; Devuyst et al., 2001; Kinzig and Grove, 2001; Ehrlich, 2002). CONCLUSIONS Ecosystem services provided by a Green Infrastructure can provide healthy environments and physical and psychological health benefits to the people residing within them. Healthy environments can contribute to improved socio-economic benefits for those communities as well. The hope and intension of this paper is to encourage the integration of information among and between the various disciplines such as the urban nature conservationists, environmental psychologists, and public health specialists to further improve urban and peri-urban environments. Fig. 1. Conceptual framework integrating Green Infrastructure, ecosystem and human health. The framework has two main parts separated by two-way arrows. The top half (ecosystem) has three interrelated boxes and the bottom half (human health) four interrelated boxes. Two-way arrows indicate two way interactions. Key: GR: green roofs; UP: urban parks; GC: green corridors; EC: encapsulated countryside; DL: derelict land; HG: housing green space and domestic gardens; CS: churchyards, cemeteries and school grounds; OW: open standing and running water; AP: air purification; CR: climate and radiation regulation; WP: water purification; SN: soil and nutrient cycling; HP: habitat provision; WD: waste decomposition; AS: aesthetic and spiritual; NP: noise pollution control; AQ: air quality; SS: soil structure; EM: energy and material cycling; WQ: water quality; HSD: habitat and species diversity; ER: ecosystem resilience; IE: income and employment; EL: education and lifestyle; LW: living and working conditions; ASH: access to services and housing; CI: sense of community identity; CE: community empowerment; SC: social capital; CL: culture; C: cardiovascular; EI: endocrine functions and immunity; N: nervous system; R: respiratory; D: digestive; B: bone tissue; RS: relaxation from stress; PE: positive emotions; AC: attention capacity; CC: cognitive capacity.
EXSUM | © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.landurbplan.2007.02.001 K