Evidence supporting the health benefits of Public Open Space
Authors: Julianna Rozek, Dr Lucy Gunn, Anna Gannet, Dr Paula Hooper, Professor Billie Giles-Corti
Providing access to high-quality public open space encourages people to be physically active and supports good mental and physical health.
Scope of evidence
There is a considerable amount of literature on the benefits of public open space to physical activity, mental health and other health outcomes.
This review primarily includes research from urban and suburban areas of Australia, the USA, Europe and, to a lesser extent, Asia.
In this section, you will learn more about:
- Quality and characteristics
- Park amenities
- Neighbourhood green space
- Ecosystem services
Good access means most homes in a neighbourhood are within easy walking distance of a green public open space. To encourage walking and cycling to these spaces, the street network should be connected, convenient and feel safe.
Residents living in neighbourhoods with good access to public open space are more likely to use such spaces and gain the associated physical activity, and mental and physical health benefits. (6,9,13,20–22,34,37,41)
Distance and quantity
There is considerable evidence that living within walking distance of parks and in neighbourhoods with more green public open space is linked to greater use of these areas and positive health outcomes. (8,22) For example, living within walking distance of green public open space has been associated with:
- Lower probability of high-normal blood pressure in women during pregnancy (23)
- Good mental health (24)
- Higher birth weights (25)
However, health benefits have also been observed from green public open space at distances much further from home. (22) People living in areas of Leicestershire, UK with higher amounts of green space within 3km and 5km of home were found to have lower levels of type 2 diabetes. (60) Similarly, more green public open space up to 4.8km from home was associated with lower mortality in Florida, USA. (61)
Many studies have focused on the relationship between access to parks and physical activity, and have found a positive association across all age groups. (6,18,19) For example, a Canadian study found that each additional hectare of park area within 1km of home increased the likelihood of an adult achieving the recommended 150 minutes or more of moderate-to-strenuous physical activity. (62) Each additional park within 1km increased this likelihood by 17%. (62)
In Australia, a longitudinal study found that adults spent around 18 additional minutes a week walking for recreation for every additional green public open space within 1.6km of their home. (63) Similarly, another Australian study found that living within 1.6km of attractive, green public open space was associated with participating in some recreational walking. (34) However, adults with larger, attractive green public open space within 1.6km of home were more likely to achieve the recommended 150 minutes of physical activity through recreational walking. This suggests that having a larger, high-quality green public open space within walking distance may be more important for promoting sufficient walking for health benefits than simply living close to smaller, lower-quality green public open space. (34) Refer to the section on Quality and characteristics for further information.
An American study of adolescents girls found a similar relationship between access to parks and physical activity. (20) Each additional park within 800m of home increased moderate-to-vigorous physical activity by 2.8%, or 17.2 minutes. While these are small increases in physical activity at the individual level, they scale up to large community-wide benefits.
Green public open space also has a positive impact on mental health. A study in Perth, Western Australia investigated the effect of parks of different sizes and types within 1.6km of home. (64) They found a significant and positive relationship between the total number and area of parks within the local neighbourhood and measures of mental health. (64) Similarly, in Los Angeles, USA mental health scores were highest in adults living up to 400m from parks and lowest in those further than 800m. (33)
However, some studies have had mixed results or found no relationship between proximity to and quantity of green public open space, and health outcomes. A US study found distance to the closest park was not significantly related to the likelihood of using parks, or park-based physical activity. (38) However, the number and total area of parks within 1.6km of home did have a positive relationship with park use and physical activity. (38)
Notably, in Melbourne, two studies also found no relationship between distance to the nearest green public open space and total area of green public open space within 1km and walking to or within these spaces. (65,66) Another small, Melbourne-based study found living within 400m of green public open space had no impact on the likelihood of depression. (67) However, residents were more likely to walk if they lived within 400m of a park larger than 1.5ha. (67)
These mixed results suggest that other features of green public open space, and not just quantity and proximity, affect whether they are used and provide health benefits. (34,65,66) For example, people may not use their closest park if it is small, uninteresting or has few amenities. (65,66)
In a study of park use by adolescents in regional Western Australia only 27% reported using their closest park for physical activity; instead parks visited by adolescents tended to have certain attributes. These included skate parks, walking paths, barbeques, picnic tables, public access toilets, lighting around courts and equipment, and more than 25 trees. (45) A study in Melbourne found that children aged 8-12 used parks which had amenities they valued, rather than their closest park. (68) Refer to Quality and characteristics for information on other features that affect whether public open spaces are used.
Neighbourhood built environment
Neighbourhoods with connected and walkable street networks encourage the use of local green public open spaces. (37,51,52) For example, greater street connectivity - measured as the density of intersections in an area - is positively associated with park use in both adults and children. (37,51,52) For further information on the features and benefits of good networks refer to Movement Networks.
Perceptions of the neighbourhood built environment also affect whether people will walk to and use parks. If the route to a green public open space is perceived as aesthetically pleasing, and safe from crime and traffic, adults are also more likely to walk there. (66) On the other hand, having to walk along or cross a high-speed road discourages walking to and using parks. (51)
For children and adolescents, their parents’ perceptions of the neighbourhood affect whether they are allowed and encouraged to walk or cycle to parks and sports centres. (52) Young people living in neighbourhoods with safe and connected streets, and easy access to parks and sports centres are more likely to use them. (52)
Indeed, a study in Brisbane, Queensland found perceptions of access were more important than objectively measured proximity to parks in determining whether an adult intended to use a park. (69)
Quality and characteristics
The characteristics of green public open space affects whether they are used and the activities they support. (8) A recent literature review found the following characteristics were important for encouraging park use and physical activity (8):
- Amenities (See Park amenities)
- Proximity (see Access)
Identifying features that are associated with use, physical activity and other health benefits can help policy-makers and practitioners design better green public open spaces.
Measurements of park quality have typically looked at the number or mix of different features, facilities and amenities and their associations with use or increased walking and physical activity. These attributes have been used to create indicators including:
- ParkIndex (70)
- Community Park Audit Tool (71)
- Public Open Space Tool (7,34)
- POSDAT: Public Open Space Desktop Auditing Tool (72)
- A park quality attractiveness score for adolescents (45)
- QUINPY: A QUality INdex of Parks for Youth (73)
Higher-quality parks generally feel safe, are well maintained and large enough to include a variety of amenities. (39) Aesthetic features, such as well-maintained vegetation, irrigated lawns and water features, also make parks more attractive. (8,74)
People are more likely to visit and be physically active in higher-quality parks, leading to greater health benefits. (8,15,34,37,38,40,70,75)
Maintenance and safety
Green public open spaces that are poorly maintained and do not feel safe discourage people from using them. (8) For example, a Western Australian study found that recreational walking was lower in parks with more disorder. (76)
Conversely, a survey of residents in a US city found that those who perceived their local parks to be clean, well-used and providing benefits to the neighbourhood were more physically active and had lower BMI. (75)
Important maintenance issues that discourage people from using parks include (8):
- Graffiti and vandalism
- Litter and pollution
- Broken and cracked paths
- Lack of lighting
- Dog faeces
Park maintenance can be a social inequity issue. A study in Melbourne found that parks in disadvantaged areas were poorly maintained and had more disorder, than those in more advantaged areas. (77)
Generally, larger green public open spaces are more used and encourage greater levels of physical activity. (7,21,34–37) A number of studies in Australia have confirmed this relationship.
Two studies in Perth, Western Australia investigated how the proximity, size and attractiveness of public open spaces affected walking in adults. (34,74) Both found that living close to large and attractive open spaces encouraged more walking compared with living close to smaller and lower-quality spaces. (34,74)
A study in Melbourne, Victoria also found that living within easy walking distance of a green public open space was associated with more walking, but only if the space was larger than 1.5ha. (67)
However, some studies have not found a clear relationship between park size, use, features and physical activity. (35,40) For example, a Danish study found no association between total physical activity in adults and the size of, distance to or number of features in the nearest green public open space. (35)
Nevertheless, people were more physically active within larger parks that had more features such as walking routes, bike racks and wooded areas. (35) These mixed results may be because physical activity is more strongly associated with the variety and number of amenities, and bigger parks have more amenities. (35)
However, there is evidence in European cities - which tend to have higher residential densities than Australian cities - that small areas of green public open space make neighbourhoods more pleasant and may provide benefits such as enhanced mental health and increased life satisfaction. (22) Smaller, high quality parks have also been positively linked to stress relief (13) and social cohesion. (78)
To date, there has been little research on the best size for public open space to promote physical activity and other health benefits. (4,21,22) While researchers and policy-makers have made suggestions to help with urban planning decision-making, more research is required to clarify the interaction between size, proximity, quality and the reasons for visiting a park.
Understanding how these factors interact would help determine how big parks should be, how far they should be located from a persons’ home, and what equipment and amenities should be included to support healthy communities.
Refurbishing parks can improve their quality and increase their use and physical activity benefits. (41–43) A recent systematic literature review of park interventions found that installing amenities or playground equipment had a consistently strong and positive impact on adult and children’s physical activity. (41)
The refurbishment of a park in Victoria with a fenced area for dogs, playground, walking track, barbeque area, and landscaping and fencing, led to significant increases in the number of park users, and people observed walking and being physically active. (42)
In a separate study, the installation of an outdoor gym led to a small, but significant increase in moderate-to-vigorous physical activity in older adult park users. (44)
However, upgrading parks without considering the wider needs of the community may not have the desired benefits. One US study observed declines in use and physical activity in five refurbished and five control parks over time. (79) Some of this decline was attributed to fewer scheduled organised activities such as sports games, caused by reduced park program budgets. While residents reported that the refurbished parks did feel safer, this was not enough to encourage people to use them. (79)
Generally, green public open spaces with more amenities are more used, support a wider range of activities and encourage higher levels of physical activity. (6,38–40)
A study in Perth, Western Australia found that high quality green public open space with more features were used by significantly more people throughout the week and for a wider variety of activities, compared with poor quality green public open space or open spaces designed only for sport. (74)
Within parks, people are more active when using features such as trails, playgrounds and sports facilities. (6) A study of park use in four Canadian neighbourhoods found that facilities such as paved trails, water features and playgrounds are more strongly related to an increase in physical activity than amenities such as drinking fountains, picnic areas and restrooms. (40) Parks with trails were seven times more likely to be used for physical activity as those without trails. (40)
Similarly, a Danish study found that physical activity in parks was related to features such as walking routes, wooded areas, water features and pleasant views. (35)
Amenities for different users
Parks should include a mix of amenities that attract people of all ages and genders. Features found to appeal to particular demographic groups include:
- Playgrounds, shaded paths and shaded seating for children and their parents (37,38,80)
- Sports fields, playground slides and skateparks for adolescents (37,45,81,82)
- Paved and unpaved trails for all age groups and genders (6,20,38,45,81)
- Designs that promote safety and security, and opportunities for socialising and contact with nature for older adults (83)
These findings are based on surveys, interviews and observations of how people use parks. For example, a study observing the activities of children and adults in 20 neighbourhood parks in the US found differences according to gender and age. (37) Organised sport amenities such as basketball courts attracted and encouraged physical activity in men, boys and adolescents - but not children younger than 13, women or girls. Features used for social functions, such as shelters and picnic areas, were attractive to older men and women, and adolescents, while playgrounds appealed to children and women.
A similar study in Canada also found age and gender-based differences in adults. (38) Men were more attracted to parks with basketball courts, water play areas and lakes, while baseball fields, trails and playgrounds appealed to women. Tennis courts, fitness stations and skate parks appealed to both genders. However, none of these facilities were significantly associated with use in older adults over 60.
Some research has investigated features attractive to particular groups. For example, a study in regional Western Australia surveyed adolescents about the parks they used most. One of the outcomes was a ‘park quality attractiveness score’ made up of seven features (45):
- Skate park
- Walking paths
- Picnic table
- Public access toilets
- Lighting around courts and equipment
- More than 25 trees
Each additional feature in a park significantly increased the likelihood it would be used by adolescents for physical activity. (45)
The preferences of different users may conflict. For example, while skateparks are very attractive to adolescent boys, they may deter older adults and discourage physical activity in adolescent girls. (20,52) The design of parks should manage these potential conflicts, and include a mix of amenities to maximise physical activity and other health benefits for the whole community.
Playgrounds are an important feature of green public open spaces because they attract children and families. (37,46,47,84) Playing in parks provides many learning and development opportunities for children, including (46):
- Learning social skills such as turn-taking, sharing, negotiation and leadership
- Cognitive development
- Sensory stimulation in younger children
- Creative problem solving in adolescents
The importance of playgrounds and the features that appeal to children may vary according to age and gender. A study in Melbourne, Victoria found the presence of a playground in a park was positively associated with younger boys’ weekend physical activity, but had the opposite effect on younger girls. (77) Furthermore, playgrounds had no effect on weekend or after-school physical activity in boys and girls aged 13-15. This may be because younger girls and adolescents prefer less formal play options. (77)
However, some studies have identified conflicting patterns of use. A US study found playgrounds encouraged both younger boys and girls to use parks, but were not important to adolescents. (37) Another US study found a positive relationship between playgrounds and physical activity levels in adolescent girls. (20)
A recent study in Melbourne, Victoria found the features most attractive to adolescents were playground slides, followed by swings and walking and cycling paths. (81) However, in an earlier study adolescents noted that a lack of variety in playground equipment across local parks was boring, and that slides and swings were sometimes too small. (86) Instead they preferred basketball rings or skate ramps and said that ‘more physically challenging play equipment would entice them to go to parks more often’. (86)
The design of playgrounds affects the benefits they provide to children. Natural playgrounds offer a blend of natural areas, environmental features and plants that interest and engage children. (46) Common features include (50):
- Creek beds
- Digging patches
- Rocks and boulders
- Natural shade
- Unstructured play areas, such as clear grassed areas and slopes
- Quiet areas
- Imaginative, creative and exploratory play areas
- Children may prefer natural playgrounds because they offer a degree of risk, making these playgrounds feel more exciting and challenging. (49,87)
Further, spending time outside and in green spaces has a positive effect on children’s mental health and development. (88–90) For example, a study on children diagnosed with attention-deficit/hyperactivity disorder found participating in after-school and weekend activities in green outdoor settings reduced their symptoms. (89)
Neighbourhood green space
Some research has investigated the relationship between health and the amount of green space around a residence. These studies generally include all green public open space, but vary on whether they include private green space such as gardens and agricultural land-uses, bushland and other conservation-focused green areas, and small patches of greenery such as street trees and nature strips. (29)
Green space is usually identified using land-use classification databases or remote sensing data. (29) For example, studies in Australia may use the Australian Bureau of Statistics classification of Mesh Blocks. (91) Mesh Blocks are small geographical units assigned a category such as residential, parkland or industrial, based on the dominant land use. (92) Alternatively, all of the vegetation in an area can be identified using satellite remote sensing data to estimate the Normalized Difference Vegetation Index (NDVI). (29)
Living in neighbourhoods with more green space has a positive effect on a variety of health outcomes, including:
Access to green space has been positively associated with a range of objective and perceived measures of mental health. Standardised surveys are a common method, and score participants based on their perceptions of well-being, mental distress, stressful experiences, and other types of health-related outcomes. (29)
A survey of 10,000 adults in the UK found those living in areas with more green spaces, including private gardens, had lower mental distress and higher well-being. (30) Another finding from the same survey was that moving to areas with more green space led to significant and long-term improvements in mental health. (31)
The mental health benefits of green space may change across adulthood, and differ in men and women. (96) A large longitudinal study in the UK found neighbourhoods with the most green space were associated with improved mental health in men, but not women. (96) When age was also considered, men benefited most in early adulthood (around 24-45 years old) while older women (over around 60) had the best mental health when living in in moderately green neighbourhoods. The causes of these differing relationships are currently poorly understood.
Living in neighbourhoods with more green space also has a positive effect on child mental wellbeing. (97) A study in NSW found a positive link between green space quantity and quality, and mental wellbeing in children aged 12-13. (97) A survey of adults in Adelaide, South Australia found a link between perceptions of neighbourhood greenness and mental health. (28) Residents who perceived their neighbourhood as being highly green had 1.6 times higher odds of better mental health than those in the least green neighbourhoods. (28)
Studies which use objective measures of mental health are less common but have also found a positive association with green space. One Scottish study measured the stress of urban residents living in deprived communities based on cortisol levels in saliva and a standard well-being survey. (93) Adults living in neighbourhoods with more green space had lower levels of self-reported and objectively measured stress. (93)
A large study in the Netherlands used medical records to examine the relationship between the prevalence of many health conditions and the amount of green space in a 1km radius of home. (32) People living in areas with more green space were less likely to suffer from a range of conditions, particularly mental disorders. For example, the annual prevalence of anxiety disorders in people with 10% green space within 1km of home was 26 per 1000, compared to 18 per 1000 for those with 90% green space. (32) For depression, the prevalence at 10% was 32 per 1000, compared to 24 per 1000 for those with 90% green space. (32)
Obesity and other health outcomes
Residents living in neighbourhoods with more green space are likely to be more physically active and less likely to be overweight or obese. (26,91) A recent longitudinal study of approximately 575,000 adults in Canada cautiously concluded that living in urban environments with more green space may be linked to a long-term reduction in mortality. (95)
A large Australia-wide survey of adults over 45 found those living in neighbourhoods with 0-20% green space were significantly less likely to walk, and participate in moderate-to-vigorous physical activity at least once a week, than those living in areas with more green space. (26) According to the same survey, women living in neighbourhoods with more green space were less likely to be overweight or obese. (98)
Similarly, a study in Perth, Western Australia found adults aged 16 to 65+ living in greener neighbourhoods were less likely to be overweight or obese. (94)
These results are consistent with the findings of a systematic literature review on the relationship between the quantity of green space and obesity-related health indicators. (27) In this review, the majority of papers (68%) analysed found a positive or weak association. (27)
However, providing lots of green space without considering other aspects of the built environment may not lead to good health outcomes. A study in Perth, Western Australia found that the risk of heart disease and stroke were comparable in the greenest and least green neighbourhoods. (99) The risk was 37% lower in neighbourhoods that had high variability in greenness.
The study suggested this may be because the attributes which contribute to high variability in greenness - such as tree-lined streets and parks in areas with good road connectivity - also make the areas more walkable. (99) Residents in these neighbourhoods may be more physically active, which is strongly associated with lower risk of heart disease and stroke. This idea is consistent with the findings of a study in NSW, which reported adults over 45 living in the most green areas were less sedentary. (91)
The benefits provided by the natural environment to humans are called ecosystem services. In the urban environment, vegetated areas have many important functions relevant to public health including maintaining a favourable climate, improving air quality and reducing traffic noise. (1)
Vegetated areas are generally cooler than the surrounding built environment and have a cooling effect on the neighbourhood. (53,57) They can effectively reduce the urban heat island effect, improving human thermal comfort reducing the risk of heat-related illnesses. (53–57) Measurements of vegetated areas in cities have found they are between 1-4°C cooler, averaging 0.9°C cooler depending on the local climate and the surrounding landscape. (53,58,100)
The size, shape and features of green spaces also impact their ability to cool the environment. Larger and smaller but connected vegetated areas have particularly strong cooling effects. (53,58) Trees, and the shade they provide, are responsible for about 80% of the cooling effect of urban vegetated areas. (101) Trees are also effective at reducing air pollution, including ground-level ozone, sulphur dioxide, smog and particulate matter. (58,59)
However, poorly designed and maintained green spaces can produce disservices. (1) For example, pollen can cause allergies, tree roots can damage side-walks and under-ground infrastructure, and falling fruit can attract pests and cause a mess. (1) These issues can be prevented and minimised with thoughtful planting and regular maintenance, and do not outweigh the multitude of health, physical activity and environmental benefits green spaces provide.
Summary of the evidence
|Adults who visit parks are more physically active and are more likely to achieve recommended levels of physical activity compared to non-users||(8,9)|
|Adults, adolescents and children who live within walking distance of parks are more likely to use them and be more physically active||(2,3,6,18–20)|
|Living within walking distance of green public open space is associated with higher birth weights, good mental health and a lower probability of high-normal blood pressure.||(21–25)|
|Neighbourhoods with more green public open space are associated with improved outcomes in physical activity, overweight and obesity, the prevalence of many health conditions, and mental health||(26–33)|
|Living within walking distance of large, attractive green public open space is associated with a greater likelihood of use and increased physical activity||(7,21,34–37)|
|Green public open space with more amenities, including trails, picnic tables, toilets and gardens, are more used and encourage higher levels of physical activity||(6,38–40)|
|Refurbishing parks by upgrading amenities can increase their use and physical activity benefits||(41–44)|
|Walking tracks and trails within parks are a highly appealing feature, and are used for a range of physical activities by all age groups and genders||(6,20,38,45)|
|Adolescents in regional cities are more likely to use parks with the following features: skate park, walking paths, barbeques, picnic table, public access toilets, lighting around courts and equipment, and more than 25 trees||(45)|
|Playgrounds attract families to parks, and provide opportunities for children to be physically active and learn social skills||(37,46–48)|
|Natural playgrounds may be preferred by children||(46,49,50)|
|Neighbourhoods with connected and walkable street networks encourage access to local green public open spaces||(37,51,52)|
|Neighbourhoods that are aesthetically pleasing and safe from crime and traffic encourage adults and children to use parks||(39, 66)|
|Green spaces have a cooling effect on the urban climate, enhancing human comfort and helping to reduce the risk of heat-related illnesses||(53–57)|
|Trees filter out air pollutants and improve urban air quality||(58,59)|