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.
Over 30 years of research has shown that urban nature is a promising tool for enhancing the physical, psychological, and social well-being of the world's growing urban population. However, little is known about the type and amount of nature people require in order to receive different health benefits, preventing the development of recommendations for minimum levels of exposure and targeted city planning guidelines for public health outcomes. Dose–response modelling, when a dose of nature is modeled against a health response, could provide a key method for addressing this knowledge gap. In this overview, we explore how “nature dose” and health response have been conceptualized and examine the evidence for different shapes of dose–response curves. We highlight the crucial need to move beyond simplistic measures of nature dose to understand how urban nature can be manipulated to enhance human health.