Different types of urban natural environments influence various dimensions of self-reported health.

BACKGROUND: Growing evidence suggests health benefits of natural environments. Yet, the effects of different types of natural environments (vegetation and water features) and forms of human-nature contact (access versus exposure) remain relatively unexplored. METHODS: A cross-sectional observational survey was used to analyse the relationship between both access and exposure to different types of urban natural environments and health outcomes in Metro Vancouver, Canada. Data for health outcomes (self-reported general health, mental health, and common mental disorders) and key confounders were obtained from the 2013-2014 Canadian Community Health Survey. Natural environments were quantified using local land use and land cover data, and linked to survey respondents by six-digit postal code. Access was defined as living within 300 m of a public greenspace (≥ 1 hectare) and exposure as the percentage of different land cover types within multiple buffer distances of postal code centroids. Separate logistic regression models were used to estimate the associations of the access and exposure metrics with the three health outcomes. RESULTS: Exposure to water within 1,000 m buffers was associated with a reduced odds of reporting poor general health (OR = 0.982, 95% CI = 0.965, 0.999). A similar association was found for exposure to shrub and grass-herb vegetation types for reported mental health and common mental disorder, respectively (OR = 0.741, 95% CI = 0.576, 0.953 for shrubs in 250 m; OR = 0.737, 95% CI = 0.577, 0.942 for shrubs in 500 m; OR = 0.731, 95% CI = 0.570, 0.938 for shrubs in 1,000 m; OR = 0.980, 95% CI = 0.965, 0.995 for grass-herbs in 250 m). Neither access to public greenspace nor aggregated greenspace exposure were associated with self-reported health. Results from stratified analyses suggest that observed associations between human-nature contact and self-reported health differ according to gender. CONCLUSIONS: Results suggest that type of natural environment should be considered in future research studying the health-promoting aspects of natural environments, and that positive health effects may be more consistent for daily life exposure than for access to public greenspace.