RESUMEN
Urban gardening is part of a trend towards more parks and green areas in cities, consumption of organic, locally grown products, and a closer relationship with one's own living environment. Our literature review shows that urban gardens provide opportunities for physical activity and allow people to consume homegrown fruit and vegetables. Urban gardens may also reduce stress levels of gardeners and improve social cohesion. In this way, they can help to prevent health problems. Good quality of urban soil and the functioning of soil ecosystems are indispensable prerequisites for these. We developed a framework that shows how ecosystem health and human health are interconnected in urban gardening, by placing it in the context of urban green space management and valuation. This study yields a set of indicators, which can be used to assess soil ecosystem services and health impacts. They may provide a basis for the evolving dialogue in decision-making processes and partnership activities in urban management. Recognizing the potential effects and discussing what is important to whom, might be enough to find synergies. Importantly, the initiators of urban gardens are often citizens, who seek support from other stakeholders. The social network established by gardens may contribute to health-enabling, cohesive communities involved with their living environment. To maximize health benefits, it is useful to make the urban gardens accessible to many people. This study suggests that urban gardens deserve a position in urban green space management as they may help to address societal challenges like urbanization, health and well-being in aging populations and climate adaptation.
Asunto(s)
Ciudades , Jardinería , Promoción de la Salud , Humanos , SueloRESUMEN
This paper is meant to initiate and feed the discussion on a more sophisticated procedure for the derivation and use of groundwater screening values (GSVs). To this purpose, the possibilities and tools for the derivation of function specific GSVs, i.e., GSVs that depend on the actual contact of humans and ecosystems with groundwater and groundwater-related mediums, are elaborated in this study. Application of GSVs geared to the specific use and function of specific groundwater volumes could result in a more effective and cost-efficient groundwater quality management, without compromising the protection of human health and the ecosystem. Therefore, a procedure to derive function specific GSVs was developed. For illustrative purposes, risk limits have been derived for human health and ecological protection targets, for arsenic, benzene, methyl tert-butyl ether (MTBE) and vinylchloride. Agriculture and Nature reserves (combined), Residential and Industrial land uses have been considered and two different groundwater management purposes, i.e., curative and sustainable groundwater management. For each of the four contaminants, this results in a series of risks limits for each function and land use combination. It is shown that for all four contaminants higher groundwater screening values are considered appropriate for less sensitive combinations of function and land use. In the process towards (policy) implementation of these function specific GSV, it is recommended to evaluate the selection of protection targets, the scientific basis of the risk assessment procedures applied and the methodology to assess the time factor for groundwater quality assessment, given the fact that groundwater is a dynamic medium. Moreover, protection levels must be harmonized with national or regional groundwater quality standards and correspond with the requirements of the Groundwater Daughter Directive of the European Union Water Framework Directive. Groundwater plumes that are judged as 'no need for remediation' are not compatible with the Water Framework Directive requirement to take actions to prevent or limit inputs of contaminants, even when no receptor is present. However, the European Commission formulated a series of exemptions, to avoid that the "prevent" requirement would imply an onerous and sometimes unfeasible task. The function specific GSVs derived in this study could be used to identify the groundwater volumes that do not result in an unacceptable risk.
Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , Ecosistema , Monitoreo del Ambiente , Humanos , Éteres Metílicos , Medición de RiesgoRESUMEN
One of the effects of climate change expected to take place in urban areas in the Netherlands is an increase in periods of extreme heat and drought. How the soil can contribute to making cities more climate proof is often neglected. Unsealed soil and green spaces increase water storage capacity and can consequently prevent flooding. The planning of public or private green spaces can have a cooling effect and, in general, have a positive effect on how people perceive their health. This paper reviews existing guidelines from Dutch policy documents regarding unsealed soil and green spaces in the Netherlands; do they support climate adaptation policies? Scientific literature was used to quantify the positive effects of green spaces on water storage capacity, cooling and public health. Finally we present a case study of a model town where different policy areas are linked together. Maps were made to provide insight into the ratio of unsealed soil and the number of green spaces in relation to existing guidelines using Geographical Information Systems (GIS). Maps marking the age and social-economic status of the population were also made. The benefits of green spaces are difficult to express in averages because they depend on many different factors such as soil properties, type of green spaces, population characteristics and spatial planning. Moreover, it is not possible to provide quantifications of the benefits of green spaces because of a lack of scientific evidence at the moment. Based on the maps, however, policy assessments can be made, for example, in which site a neighborhood will most benefit from investment in parks and public gardens. Neighborhoods where people have a low social-economic status have for example fewer green spaces than others. This offers opportunities for efficient adaptation policies linking goals of several policy fields.
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Ciudades/estadística & datos numéricos , Conservación de los Recursos Naturales/métodos , Monitoreo del Ambiente , Sistemas de Información Geográfica , Países Bajos , Salud Pública , Factores Socioeconómicos , Suelo , Salud Urbana , Abastecimiento de Agua/estadística & datos numéricosRESUMEN
This article presents and discusses the main elements for a fundamental policy change for groundwater management in The Netherlands. The study analyzes the status and current use of groundwater, the increasing pressure in The Netherlands and many other countries on the natural soil-water system, the effects on quality and quantity of groundwater and the use of the subsoil. An overview is given of the current national and European regulations regarding groundwater and related policies for e.g. drinking water, soil policies and other interventions in the subsurface. The Dutch National Government is developing a new framework for groundwater management that aims a sustainable use of groundwater not only in environmental, but also in economic and social perspective. This framework for groundwater will benefit the Structure vision on the subsoil. The question is how 'sustainable use' can be a guiding principle in groundwater management, strengthening the relation between groundwater quantity and quality. It is proposed to define a generic National approach for the assessment of new and existing activities with potential effects on groundwater and for groundwater quality assessment. Additionally it is proposed to give local authorities the opportunity to set area-specific objectives on a regional or local scale to adjust for specific societal needs and area-specific characteristics. For setting these objectives it is recommended to use the concept of ecosystem services as a leading principle for defining the groundwater quality and quantity (e.g. for use as source for drinking water, aquifer thermal storage and sustaining terrestrial and aquatic ecosystems).
Asunto(s)
Conservación de los Recursos Naturales/métodos , Política Ambiental , Agua Subterránea/química , Formulación de Políticas , Contaminación del Agua/prevención & control , Ecosistema , Monitoreo del Ambiente , Países Bajos , Contaminantes Químicos del Agua/análisis , Contaminación del Agua/estadística & datos numéricos , Abastecimiento de Agua/normasRESUMEN
Consumption of vegetables that are grown in urban areas takes place worldwide. In developing countries, vegetables are traditionally grown in urban areas for cheap food supply. In developing and developed countries, urban gardening is gaining momentum. A problem that arises with urban gardening is the presence of contaminants in soil, which can be taken up by vegetables. In this study, a scientifically-based and practical procedure has been developed for assessing the human health risks from the consumption of vegetables from cadmium-contaminated land. Starting from a contaminated site, the procedure follows a tiered approach which is laid out as follows. In Tier 0, the plausibility of growing vegetables is investigated. In Tier 1 soil concentrations are compared with the human health-based Critical soil concentration. Tier 2 offers the possibility for a detailed site-specific human health risk assessment in which calculated exposure is compared to the toxicological reference dose. In Tier 3, vegetable concentrations are measured and tested following a standardized measurement protocol. To underpin the derivation of the Critical soil concentrations and to develop a tool for site-specific assessment the determination of the representative concentration in vegetables has been evaluated for a range of vegetables. The core of the procedure is based on Freundlich-type plant-soil relations, with the total soil concentration and the soil properties as variables. When a significant plant-soil relation is lacking for a specific vegetable a geometric mean of BioConcentrationFactors (BCF) is used, which is normalized according to soil properties. Subsequently, a 'conservative' vegetable-group-consumption-rate-weighted BioConcentrationFactor is calculated as basis for the Critical soil concentration (Tier 1). The tool to perform site-specific human health risk assessment (Tier 2) includes the calculation of a 'realistic worst case' site-specific vegetable-group-consumption-rate-weighted BioConcentrationFactor.