The World Health Organisation’s review, “Urban green spaces and health – A review of evidence” summarises the existing evidence of health effects of urban green spaces and concludes, “There are many public health benefits, such as psychological relaxation and stress reduction, enhanced physical activity, and mitigation of exposure to air pollution, excessive heat, and noise as well as other harmful factors in the urban environment. These numerous benefits strongly outweigh potential detrimental effects of green spaces such as exposure to allergenic pollen and to infections carried by insect vectors. In addition, most detrimental effects are associated with poorly maintained green spaces; they can be reduced or prevented through proper planning, organization and maintenance of green urban areas.”
The informed work of landscape architects, planners and urban designers is important in contributing professional expertise to ensure that health benefits as well as environmental and economic co-benefits of green spaces are maximised and future opportunities are not lost through short‐sighted urban development decisions.”
The main objectives of this report are to inform public health specialists and policy‐makers on the benefits of providing urban residents with green space access, and to provide cities with systematic approaches to quantifying and monitoring their green space access. This report advocates the implementation and evaluation of targeted, evidence‐based green space interventions for the health promotion of urban residents.
Many of the mechanisms behind such links have been poorly understood or lacked rigorous scientific evidence. A refined understanding of the health promotion potential of urban green spaces can contribute to addressing major public health issues related to non-communicable diseases. Preventable non-communicable diseases, such as mental illness, obesity, cardiovascular diseases, type 2 diabetes and cancer, remain major factors not only affecting health and well‐being, but also driving up the cost of health care and reducing the productivity of the workforce. Many such illnesses are linked to chronic stress and lifestyle factors, such as insufficient physical. Urban green spaces, as part of a wider environmental context, have the potential to help address problems in a preventative way – considered a more efficient approach.
At the Fifth Ministerial Conference on Environment and Health in Parma, Italy, the Member States of the WHO European Region made a commitment “…to provide each child by 2020 with access to healthy and safe environments and settings of daily life in which they can walk and cycle to kindergartens and schools, and to green spaces in which to play and undertake physical activity”. Improving access to green spaces in cities is also included in the United Nations Sustainable Development Goal, which aims to achieve the following: “By 2030, provide universal access to safe, inclusive and accessible, green and public spaces, in particular for women and children, older persons and persons with disabilities”. Finally, the WHO Action Plan for the implementation of the European Strategy for the Prevention and Control of Non-communicable Diseases in 2012−2016 includes a call to create health supporting urban environments.
The WHO report on urban planning, environment and health published in 2010 states that green spaces can positively affect physical activity, social and psychological well‐being, improve air quality and reduce exposure to noise; however, they can also be associated with an increased risk of injury due to increased recreational and sport‐related use. Another WHO report evaluated the effects of green spaces on physical activity and their potential to reduce public health inequalities. It states that “… access to public open space and green areas with appropriate recreation facilities for all age groups is needed to support active recreation”, but recognizes that multidisciplinary and inter-sectoral interventions may be needed to support disadvantaged groups where physical activity levels are lowest. Recent studies have provided evidence of multiple benefits from urban green space, through various mechanisms, and with potentially differential impacts in various populations. Epidemiological studies have used a multitude of approaches to measure the effects of urban green space availability and accessibility on the health outcomes of study participants. Given the potential of urban green spaces to act as settings for health promotion it is therefore necessary to summarize the existing evidence identifying, where possible, the underlying mechanisms contributing to both the negative and positive health outcomes of urban green space. There is also a need to summarize existing understandings of the characteristics of urban green space that may differentially be associated with 2 health outcomes, and to understand how different populations may be affected and benefit in different ways.
“A city of well‐connected, attractive green spaces that offer safe opportunities for urban residents for active mobility and sports as well as for stress recovery, recreation and social contact, is likely to be more resilient to extreme environmental events, such as heat waves (due to the mitigation of urban heat island effect) and extreme rainfall (due to reduced surface run‐off). Such a city is also likely to have healthier citizens, reducing demands on health services and contributing to a stronger economy.”
WHO Urban green spaces and health – A review of evidence, 2016.
This report offers a review of the existing evidence on the health effects of green space in urban areas alongside a summary of health‐relevant measures of green space availability, accessibility and usage. The report also presents a toolkit outlining an example of a Geographic Information System based approach to measuring urban green space that WHO has recently applied in three European cities. The review is an overview of previous WHO reports and other previously published reviews as well as selected recent research publications.