Nature within cities will have a central role in helping address key global public health challenges associated with urbanization. However, there is almost no guidance on how much or how frequently people need to engage with nature, and what types or characteristics of nature need to be incorporated in cities for the best health outcomes. Here we use a nature dose framework to examine the associations between the duration, frequency and intensity of exposure to nature and health in an urban population. We show that people who made long visits to green spaces had lower rates of depression and high blood pressure, and those who visited more frequently had greater social cohesion. Higher levels of physical activity were linked to both duration and frequency of green space visits. A dose-response analysis for depression and high blood pressure suggest that visits to outdoor green spaces of 30 minutes or more during the course of a week could reduce the population prevalence of these illnesses by up to 7% and 9% respectively. Given that the societal costs of depression alone in Australia are estimated at AUD$12.6 billion per annum, savings to public health budgets across all health outcomes could be immense.
Engagement with nature is an important part of many people’s lives, and the health and wellbeing benefits of nature–based activities are becoming increasingly recognised across disciplines from city planning to medicine. Despite this, urbanisation, challenges of modern life and environmental degradation are leading to a reduction in both the quantity and the quality of nature experiences. Nature–based health interventions (NBIs) can facilitate behavioural change through a somewhat structured promotion of nature–based experiences and, in doing so, promote improved physical, mental and social health and wellbeing. We conducted a Delphi expert elicitation process with 19 experts from seven countries (all named authors on this paper) to identify the different forms that such interventions take, the potential health outcomes and the target beneficiaries. In total, 27 NBIs were identified, aiming to prevent illness, promote wellbeing and treat specific physical, mental or social health and wellbeing conditions. These interventions were broadly categorized into those that change the environment in which people live, work, learn, recreate or heal (for example, the provision of gardens in hospitals or parks in cities) and those that change behaviour (for example, engaging people through organized programmes or other activities). We also noted the range of factors (such as socioeconomic variation) that will inevitably influence the extent to which these interventions succeed. We conclude with a call for research to identify the drivers influencing the effectiveness of NBIs in enhancing health and wellbeing.
Nature relatedness is a psychological characteristic with the potential to drive interaction with nature and influence well-being. We surveyed 1538 people in Brisbane, Australia to investigate how nature relatedness varies among socio-demographic groups. We determined whether people with higher nature relatedness reported fewer symptoms of depression, anxiety, stress and better overall health, controlling for potentially confounding socio-demographic and health-related variables. Overall nature relatedness was higher in older people, females, those without children living at home, not working, and people speaking English at home. Aspects of nature relatedness reflecting enjoyment of nature were consistently associated with reduced ill health, consistent with widespread evidence of the health and well-being benefits of experiencing nature. In contrast, aspects of nature relatedness reflecting self-identification with nature, and a conservation worldview, were associated with increased depression, anxiety or stress, after accounting for potential confounding factors. Detailed investigation of causal pathways among nature relatedness, socio-demographic factors and health is warranted, with particular focus on the relationship between stress and nature orientation.