We asked whether green space availability in urban areas of New Zealand was equitable between affluent and deprived communities, and whether green space was independently associated with health differences. We also intended to examine the evidence for the different pathways by which green space availability may influence health outcomes (e.g., by providing physical activity opportunities or stress relief) by contrasting health associations for different types of green space.
We produced a detailed classification of green space availability for New Zealand, which differentiated between usable (i.e., visitable) and non-usable (i.e., visible but not visitable) areas. Counts of mortality from cardiovascular disease (plausibly related) and lung cancer (a ‘control’) over 10 years were obtained for 1009 urban neighbourhoods (population = 1.5 million). We found that deprived neighbourhoods had less green space in total than affluent areas, but had slightly more green space that was usable (e.g., parks and playing fields). Contrary to expectations we found no evidence that green space influenced cardiovascular disease mortality in New Zealand, suggesting that green space and health relationships found in other countries may vary according to national, societal or environmental context. Hence we were unable to investigate evidence for the causal pathways in the relationship. Green space variation may have lesser relevance for health in New Zealand because green space is generally more abundant and there is less social and spatial variation in its availability than found in other contexts.
You can download the green space data set we used in this study from here.
Richardson EA, Pearce J, Mitchell R, Day P, Kingham S. The association between green space and cause-specific mortality in urban New Zealand: an ecological analysis of green space utility. BMC Public Health 2010; 10(1):240.http://dx.doi.org/10.1186/1471-2458-10-240