courtesy  :  bmc public health

Vitamin G: effects of green space on health, well-being, and social safety

Previous (experimental) research in environmental psychology has shown that a natural environment has a positive effect on well-being through restoration of stress and attentional fatigue. Descriptive epidemiological research has shown a positive relationship between the amount of green space in the living environment and physical and mental health and longevity.

The program has three aims. First, to document the relationship between the amount and type of green space in people’s living environment and their health, well-being, and feelings of safety. Second, to investigate the mechanisms behind this relationship. Mechanisms relate to exposure (leading to stress reduction and attention restoration), healthy behavior and social integration, and selection. Third, to translate the results into policy on the crossroads of spatial planning, public health, and safety. Strong points of our program are: we study several interrelated dependent variables, in different ordinary settings (as opposed to experimental or extreme settings), focusing on different target groups, using appropriate multilevel methods.

The briefest summary of our program is in its title: Vitamin G, where G stands for the green space around us. Notions of beneficial effects of nearby green space have persisted throughout history [1]. Research on this topic, mainly experimental research, has focused on demonstrating the relationship between exposure to green environments and well-being [2, 3]. Most of the evidence on health benefits comes from laboratory experiments that exposed participants to photographic simulations of various types of natural environments [4], or controlled field studies that compared residents with a view of urban greenery to residents without such view [5]. This research has demonstrated that mere exposure to views of nature can improve people’s health and well-being by providing restoration from stress and mental fatigue. Moreover, this research has shown that views of nature can improve feelings of neighborhood safety and even lead to decreases in aggression and crime rates [6, 7]. To maximize effects, scientists have selected extreme settings, such as urban areas with nearly no green space at all, and concentrated on stress reduction and attention restoration as the most noticeable outcomes. Theoretical developments have followed this focus, and the dominant theories in the field [8, 2] consider stress reduction and restoration as a central causal mechanism. Although this focus on extreme settings and restorative effects has highlighted the importance of green space to well-being, it potentially obscures the scope and underlying mechanisms of these effects. Very little is known about the positive effects of green space on well-being through mechanisms of increased and prolonged physical activity, and improved social cohesion [9, 10]. Not only causal mechanisms might explain the effects of green space; research in naturalistic settings also has to take into account the possibility of direct or indirect selection [11, 12].

Vitamin G aims to establish the relationship between the amount and type of green space in people’s living environment and their health, well-being, and feelings of safety, to study the mechanisms behind this relationship, and to specify the implications for policy making. Our program differs from previous studies in two respects.

First of all, field studies will be conducted instead of experimental studies; this is especially important for applied purposes, because it provides a better indication of the relative size of the effects in real-life settings. Field studies also have higher ecological validity, a more direct social relevance, and a focus on long-term rather than on short-term effects (almost inevitable in the case of laboratory studies). Secondly, the focus is on ordinary settings instead of ‘extreme’ settings in which people are especially stressed or frustrated (hospitals, prisons), or live in extremely poor or barren circumstances (as in some of the previous studies: [13–15]). This increases the generalizability of the effects and the relevance to the European and especially the Dutch situation.

In this article we describe the research questions and background of the program as a whole and the design and methodology of the three separate projects that form the program. Vitamin G started on 1 January 2005 and will run for four years.

The program vitamin G

The general problem formulation of our research program is: what is the direction and strength of the relationship between the amount of green space in people’s living environment and their health, well-being and perceived safety, how can this relationship be explained and how can the results be made useful for policy intervention? This general question will be answered in three projects at three different scales: at a macro scale using data on the Netherlands as a whole, at an intermediate scale looking into the specific effect of green space in the urban environment, and at micro scale investigating the effects of allotment gardens. The specific problem formulations for each of these three projects are:

1. How strong is the relationship between the amount of green space in people’s living environment and their perceived health and well-being, and feelings of safety and is this relationship stronger for specific population segments and/or types of green space? How can this relationship be explained?

2. Do urban neighborhoods that differ in the amount and type of green space in the vicinity, also differ in the health, well-being and perceived safety of the people living in these neighborhoods? Have urban neighborhoods that went through a large change in the amount of green space, changed in these respects? If so, which aspects of the green space seem to be the most influential ones?

3. Is having an allotment garden related to health, well-being and perceived safety in urban dwellers and how can this relationship be explained?

Our approach to answer these questions is based on analyzing the multilevel relationships between environment and people [16, 17]. People live in a shared environment that influences their well-being in a general sense, even partly by virtue of the fact that it is a shared environment (as in the case of social integration).