Better Parks, Healthier for All?

Poor mental health and cardiovascular disease are big public health problems that have impacts on a lot of people's lives. We know that being in and around nature can help prevent these problems. Increasing numbers of us live in cities these days and so our access to nature comes through places like parks and city woodlands. These 'green spaces' have different characteristics. For example, some are well-managed with football pitches, open lawns, toilets and just a few trees lining paths, but others might be woodlands with fewer facilities but perhaps lots of birds and wildlife. We use the word 'qualities' to describe these characteristics. There is already quite a lot of research about how to measure the qualities of a green space, but surprisingly, there is little research which asks which qualities bring greater benefits for mental heath and cardiovascular disease. If you are a city planner or manager, there is no good evidence to tell you how to design, plan, create and manage your green spaces to best prevent these health problems. One obvious thing is that different kinds of green space will offer different kinds of qualities, and not everyone wants the same thing from a park or woodland. We think having a range of different kinds of green spaces with a reasonable distance of people's homes is probably more important than having just one that tries to offer everything.

To do this research we're going to measure the qualities of lots of different green spaces in four cities in Scotland (Glasgow and Edinburgh) and Australia (Sydney and Wollongong). Then we're going to join these new data together with existing data about people who live in those cities. We have very good measures of mental health and the things that lead to cardiometabolic problems for lots of people who live in these cities. We'll ask whether some particular qualities of green spaces seem linked to better mental health and to lower risk of cardiometabolic diseases. In particular, we'll ask if these links are the same for different kinds of people; richer and poorer, male and female, older and younger. It would be expensive and time consuming to have our team visit every green space in these cities and assess its quality, so we are going to use images from Google Earth, map data and other existing survey work on the biodiversity and vegetation in the parks to assess them. Then we will visit a few of the green spaces to check that these measures are accurate and work well. How will we know what to measure? We will work with real planners, designers and managers of green spaces, right through our project, to ensure that we measure the things they can affect, and that we don't reinvent wheels they already have. This is called 'co-production'.

We're doing this work in Scotland and Australia because both countries share problems with poor mental health, with bad rates of CVD and with gaps in health between different kinds of people, but of course the people there may want different things from their green spaces and use them in different ways. Comparing these places will help the planners and city managers in both countries understand what they have in common, what's different and what to do. Our results will also help people in other cities too. Another reason for working together is that the team has already successfully worked together and has skills and experiences that complement each other. Our work will be good value for money because we're using data sets that have already been paid for. We'll make the data about green space qualities available for the public to see on a website, and share our results with the people who plan and manage city environments everywhere - not just in Scotland and Australia. We will help nature help us all to stay healthier.

Both experimental and observational studies suggest that contact with nature reduces risk of poor mental health and also cardio-metabolic disease. This effect operates via a variety of aetiological pathways, including increased physical activity and stress reduction via psycho-neuro-endocrine routes. Urban green spaces (the primary exposure to nature for an increasing proportion of humanity) have a variety of designs, facilities, features, vegetation structure and biodiversity levels which plausibly influence the strength and effectiveness of their influence on NCDs. We refer to these as 'qualities'. There has been no systematic, longitudinal assessment of associations between a range of green space qualities, and robust NCD risk factors or outcomes. We will test the hypothesis that higher quality green spaces drive reductions in the risk of, and inequalities in, mental ill-health and cardiometabolic diseases; and a well-connected network of nearby green spaces with diverse qualities and sizes will be a more effective community health intervention than any single high-quality green space. Whilst the state and third sectors in Australia and the UK have blueprints for what to capture in measuring qualities, there are no spatially comprehensive validated secondary measures of green space quality available. We will therefore first co-produce measures of urban green space qualities for 4 cities in Scotland and Australia, using remote imagery including Google earth, Lidar and secondary crowd-sourced biodiversity measures. These will be validated via primary survey. We will then assess, via data linkage, association between green space qualities and robust measures of mental health, cardiometabolic diseases, biomarkers, hospitalisations and risk factors. The health data will come from the 45 and Up Study in Sydney and Wollongong and the UK Biobank in Edinburgh and Glasgow. Co-design of policy options with a multisector advisory group will be informed by our new evidence.

Who might benefit from this research?

The urban dwelling public, particularly (but not exclusively) of Scotland and Australia, will be key beneficiaries of this research as it seeks to maximise and equalise the qualities of urban green spaces, and minimise and equalise the risk of developing NCDs. If we are successful, less advantaged groups will benefit most as we seek to maximise the equalising effect of urban green space on health. The designers, planners and managers of urban green spaces, including our key partners, will also benefit as they will have greater evidence on which to base their actions, and with which to argue for the protection of existing and creation of new, green spaces. All academics concerned with the role, meaning and impacts of natural environments and their use will benefit from both greater capacity for research, and new understanding of the role that such environments might play in preventing NCDs and minimising inequalities. This is a multidisciplinary endeavour with clinical, social and economic scientists all likely to benefit.

How might they benefit from this research?

In the long term, networks of urban green spaces with qualities shown to have maximum impact on risks of NCDs and inequalities in NCDs should contribute to reducing and equalising NCD rates. Our plans to co-produce this evidence with people who control and influence design, planning and management of these environments, will enable this change to actually happen. In the shorter-term, new and free availability of data on the qualities of urban green spaces in the cities of Sydney, Wollongong, Glasgow and Edinburgh will enable people to understand their environment better, perhaps to choose to visit or experience different kinds of spaces and, crucially, to better engage in the participatory planning and budgeting processes that these cities have. Our experience is that sharing data enables people. Academics too, will be able to use these data and the blueprint for their creation in their own work. Since the new data will be based on freely available resources, they are therefore replicable by other academics for their own study areas. Quality of green space has long been 'the missing link' in epidemiological study of its health impacts, but also in sociological and psychological study of its use and meaning.