Many of us know intuitively that green space matters. Real estate agents tell us that houses backing on to green space can cost $10,000 more than other homes in the same neighbourhood. Studies suggest that easy access to green space is an important neighbourhood feature for many people. However, land use planners have found that it can be difficult to preserve green space in the face of competing priorities and development pressures. In this context, public health professionals and planners from conservation authorities, parks and recreation departments, and school boards, have created a new organization, EcoHealth Ontario, through which they can collaborate on projects which examine the health benefits associated with green space.
On March 24, EcoHealth Ontario, with support from the Friends of the Greenbelt Foundation, and in association with The Ontario Public Health Convention, hosted a workshop entitled, “Realizing the Health Benefits of Green Spaces in a Changing World“. Convened in Toronto, the workshop attracted 150 participants from conservation authorities, public health units, school boards, parks and recreation, and non-governmental organizations.
Dr. Charles Gardner, the Medical Officer of Health for the Simcoe Muskoka District Health Unit, began the day by providing an overview on the many ways in which greenspace can affect the lives of people. While he touched on issues related to water quality, physical activity, mental health, air quality and climate change, he ended by offering: “nature is beneficial to health but more importantly, it is essential to our existence”.
Tara Zupancic, Director of Habitus Research, provided a high level summary of a literature review, produced for the David Suzuki Foundation, directed at the impact of green space on air quality and heat mitigation. She reported that: “all types of green space have a positive impact on heat in urban centres”. She also noted that: “as size and/or continuity of green space increases, the heat reduction benefits increase”. She concluded by suggesting that green space, which tends not to be equitably distributed in urban centres, may provide greater health benefits for low income populations that are most vulnerable to heat waves.
Zupancic reported that green space’s impact on air quality is more complicated. She explained that green space can improve air quality by improving the movement of air or by removing pollutants such as fine particulate matter from the air. However, she noted that some trees release volatile organic compounds (VOCs) that can contribute to smog, and in some situations, trees that line street canyons with heavy traffic can concentrate levels of air pollution on those streets.
Ronald Macfarlane, Manager in the Healthy Public Policy Directorate of Toronto Public Health, presented the principal findings from a literature review prepared for Toronto Public Health by Tara Zupancic which looked at the impact of green space on physical activity and mental health. He began by noting that there are many different types of green space in an urban area including natural areas, parks, community gardens, playgrounds, street trees and front and back yards. He explained that, when the findings of 102 studies of green space and mental health were taken as a whole, “it appears that all types of green space are associated with some mental health benefits”.
Macfarlane reported that the link between physical activity and green space is less clear; that certain features of green space, such as linear trails and recreational amenities, appear to increase levels of physical activity, while other types of green space do not. He also noted that: “the literature suggests that green space may have greater health benefits for people who live on low incomes than on those who live on higher incomes”.
The presentations from the day can be found on the Ontario EcoHealth website at: EcoHealth Ontario Resources along with summaries of the two new reports. The full report on air quality and heat mitigation can be accessed at: The Impact of Green Space on Heat and Air Pollution in Urban Communities. The report on mental health and physical activity will be released by Toronto Public Health in June 2015.
Prepared by Kim Perrotta, Executive Director (Volunteer), CHASE Canada, Kim Perrotta/LinkedIn