No abstract

BackgroundThere is mounting international evidence that exposure to green environments is associated with health benefits, including lower mortality rates. Consequently, it has been suggested that the uneven distribution of such environments may contribute to health inequalities. Possible causative mechanisms behind the green space and health relationship include the provision of physical activity opportunities, facilitation of social contact and the restorative effects of nature. In the New Zealand context we investigated whether there was a socioeconomic gradient in green space exposure and whether green space exposure was associated with cause-specific mortality (cardiovascular disease and lung cancer). We subsequently asked what is the mechanism(s) by which green space availability may influence mortality outcomes, by contrasting health associations for different types of green space.MethodsThis was an observational study on a population of 1,546,405 living in 1009 small urban areas in New Zealand. A neighbourhood-level classification was developed to distinguish between usable (i.e., visitable) and non-usable green space (i.e., visible but not visitable) in the urban areas. Negative binomial regression models were fitted to examine the association between quartiles of area-level green space availability and risk of mortality from cardiovascular disease (n = 9,484; 1996 - 2005) and from lung cancer (n = 2,603; 1996 - 2005), after control for age, sex, socio-economic deprivation, smoking, air pollution and population density.ResultsDeprived neighbourhoods were relatively disadvantaged in total green space availability (11% less total green space for a one standard deviation increase in NZDep2001 deprivation score, p < 0.001), but had marginally more usable green space (2% more for a one standard deviation increase in deprivation score, p = 0.002). No significant associations between usable or total green space and mortality were observed after adjustment for confounders.ConclusionContrary to expectations we found no evidence that green space influenced cardiovascular disease mortality in New Zealand, suggesting that green space and health relationships may vary according to national, societal or environmental context. Hence we were unable to infer the mechanism in the relationship. Our inability to adjust for individual-level factors with a significant influence on cardiovascular disease and lung cancer mortality risk (e.g., diet and alcohol consumption) will have limited the ability of the analyses to detect green space effects, if present. Additionally, 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.

Neighbourhood access to opportunities for gambling is related to gambling and problem gambling behaviour, and contributes substantially to neighbourhood inequalities in gambling over and above-individual level characteristics.

No abstract

The prevalence of obesity has increased rapidly across the globe over the past three to four decades. In New Zealand in 2006/07 over a third of adults were overweight and a further 27% were obese, with higher prevalence rates in more deprived neighbourhoods. Rates were also high for children, with 21% of 2^14 year olds overweight and 8% obese (Ministry of Health, 2008). While increasing body size at the individual level can be understood as arising from an imbalance between energy intake and energy expenditure, explaining why such a large-scale change in body size has occurred at a population level has been harder to pin down. It is increasingly apparent that to understand the worldwide rise in obesity prevalence it is necessary to consider a whole host of environmental factors that operate at a range of geographical scales (Pearce and Witten, 2010). On the energy-expenditure side of the weight equation, lifestyle changes that have reduced physical activity levels include steep rises in car reliance and the use of labour-saving devices in the home and workplace (Giles-Corti et al, 2010). Reduced levels of active transport and increased sedentary behaviours provide a plausible pathway to partially explain the sharp rise in overweight and obesity levels. Accordingly, the impacts of motor vehicle use on physical activity behaviours and on the design of our cities have come under close research scrutiny.A recursive relationship exists between car ownership rates and urban form: as a city sprawls, the distances between home, work, and the other destinations of daily life tend to increase along with car ownership (Social Exclusion Unit, 2003)