Urban Green Spaces: Our tools to build a “balance-maker” habit

The world is facing unprecedented urban population growth, putting the relationship between humans and the environment in an unfamiliar context. Although there has been academic attention on the ecological impacts of urbanization, less is known about the relationship between urban development and human health. As more and more people move to urban areas all over the world, more and more questions arise regarding how exposure to the urban environment is linked to the health of humans. In parallel with massive urbanization, we as human beings have been living in a world full of smart devices, social media options, and technology-based platforms. Technology has become a solid and constant element of many people’s lives, as they spend a considerable amount of time on smartphones and online.

Although massive urbanization and technological advancements have created faster and smarter ways of living, our current generation is at higher risks of physical inactivity and social isolation [1].

BALANCING PHYSICAL INACTIVITY
According to the Canadian Institute of Health Information, physical inactivity is the biggest contributor to obesity, which increases the risk for heart disease, stroke, some types of cancer, and type II diabetes. Obesity prevalence rates in Canadian adults are projected to continue to increase over the next two decades [2]. Between 1990 and 2010, childhood obesity in the world increased from 4.2% to 6.7%, being higher in developed countries (7.9% to 11.7%) as compared to developing ones (3.7% to 6.1%) [2].

Technology and urbanization both have impacts on our daily physical activity routines. Too much technology is associated with a sedentary lifestyle (watching TV, using a phone/computer, playing video games). On the other hand, living in low-density urban areas puts the residents at greater risks of obesity by encouraging people to drive instead of daily physical walks to their desired destinations.

BALANCING SOCIAL ISOLATION
Regarding social isolation, it may be worth referring to the book Bowling Alone by Robert D. Putnam, which described the decline of social capital and reduction in all forms of in-person social interaction in the United States since 1950 [11]. 

Unfortunately, research shows that mobile technology is affecting communication in a negative way when it comes to sociability and in-person communication [3]. Moreover, the current suburban form does not support a healthy social network because it offers limited opportunities for face-to-face meetings [3]. The present urban system does not take the social costs of distancing into account either and ignores the negative impacts of car-dependency resulting from the spatial distribution of urban zones on the social capital [3].

BALANCING URBAN GREEN SPACES
What we might be missing out on is the capacity of our cities and their urban green spaces to nourish our daily habits, encouraging us get more active and bringing us together. Keeping privacy while being in the crowd, maintaining neighbourhood social cohesion, and increasing the chance of face-to-face interactions are all social benefits of urban green spaces that may provide a real-world alternative to tech-based socialization [4].

Higher levels of physical activity among the residents of greener neighborhoods has been reported in many studies. In a Canadian survey, positive associations were reported between greenness and physical activity, independent of income level [5]. Physical activity levels also play a protective role against health disorders because physical activity increases energy expenditure [6]. As the energy expenditure increases, the risk of hypertension and obesity are reduced [6].

Therefore, we may conclude that being exposed to urban green spaces may be considered a non-medical prescription to help us respond to the challenges of physical inactivity and social isolation among urban communities.

Exposure to urban green spaces can be called a "balance-maker" habit, helping us have more physical activity while maintaining social cohesion.

BALANCING HUMAN WELL-BEING
Also worth exploring are the effective features of urban green spaces in contributing to human well-being. Here are four factors that could impact the links between urban green spaces and human physical and mental health benefits. In other words, these four factors were used as independent variables in evaluating the “value” of urban green spaces in terms of their health benefits. These four factors include:

1. Biodiversity
The term biodiversity is an umbrella term that defines the biological diversity and number of species and habitats [7]. It has been understood that the experience of biodiversity and other characteristics of nature are associated with greater well-being [7]. Fuller et al. (2007) found a correlation between higher bird and plant diversity and gained benefits of visiting urban green spaces [7]. Comparably, Cox et al. (2017) reported that vegetation cover and afternoon bird abundance in urban areas reduced the severity of depression, anxiety and stress [7].

2. Site Facilities
A site facility is considered to be a non-biological factor that can be assessed by subjective tools [7]. Various parameters include lighting, adequate seating, signs, and indications of good management such as cut grass and lack of graffiti or litter that make green spaces feel safe and desirable [7].

3. Quality of Vegetation (NDVI)
The Normalized Difference Vegetation Index (NDVI) has been mentioned as an independent variable in investigating health benefits of urban green spaces [5]. NDVI takes on values between 0 and 1, where 1 stands for the healthiest and densest vegetation that is able to not only absorb red and blue light (visible light or VIS), but also reflect green and near-infrared light (NIR) [8]. NDVI was used as an indicator of residential greenness in studies on the health impacts of urban green spaces [9]. Higher mean value of NDVI in the proximity of residential units have been associated with better health outcomes [9]. 

4. Residential Proximity
The distance between urban green spaces and residential units are shown as independent factors, while positive health impacts are dependent factors. Cohen et al. reported that adolescent girls living within 0.5 miles of park space were more likely to engage in non-school-related, moderately-vigorous physical activity [4]. Cohen et al. demonstrated that residential proximity was strongly associated with park use and physical activity [4].

Identifying the above four features may set a platform to establish a framework towards optimizing health benefits through an evidence-based design.
Referring to the book Triumph of The City, the city is humanity's greatest invention and our best hope for the future [10]. Urban green spaces are the city’s best assets and offer to help us solve the big problems we face.
 

Reference List

1. Briki, W., & Majed, L. (2019). Adaptive Effects of Seeing Green Environment on Psychophysiological Parameters When Walking or Running. Frontiers in Psychology, 10, https://doi.org/ 10.3389/fpsyg.2019.00252.
2. Fisberg, M., Maximino, P., Kain, J., & Kovalskys, I. (2016). Obesogenic environment --- intervention opportunities. Jornal de Pediatria, 92, http://dx.doi.org/10.1016/j.jped.2016.02.007.
3. Montgomery, C. (2013). Happy City. Farrar, Straus and Giroux, Random House, Penguin Books.
4. Lee, A. C. K., & Maheswaren, R. (2010). The health benefits of urban green spaces: a review of the evidence. Journal of Public Health, 86, 212–222.
5. Demoury, C., Thierry, B., Richard, H., Sigler, B., Kestens, Y., & Parent, M. (2017). Residential greenness and risk of prostate cancer: A case-control study in Montreal, Canada. Environment International, 98, 129-136.
6. Richardson, E. A., Pearce, J., Mitchell, R., & Kingham, S. Role of physical activity in the relationship between urban green space and health. Public Health, 127, 318-324.
7. Wood, E., Harsant, A., Dalimer, M., Cronin de Chavez, A., McEachan, R. R. C., Hassall, C. (2018). Not All Green Space Is Created Equal: Biodiversity Predicts Psychological Restorative Benefits from Urban Green Space. Frontiers in Psychology, 9, https://doi.org/10.3389/fpsyg.2018.02320.
8. Kondo, M. C., Fluehr, J.M., Mckeon, T., & Branas, C. C. (2018). Urban Green Space and Its Impact on Human Health. International Journal of Environmental Research and Public Health, 15, https://doi.org/10.3390/ijerph15030445.
9. Albeit, K., & McLafferty, S. (2017). Green Streets: Urban Green and Birth Outcomes. International Journal of Environmental Research and Public Health, 14, https://doi.org/10.3390/ijerph14070771.
10. Glaeser, E. (2011). Triumph of The City. Penguin Publishing Group.
11. Putnam, R. D. (2000). Bowling Alone. Simon & Schuster.