Research shows trends toward positive associations between urban green and blue spaces and health in children and the elderly, but results are inconclusiveThe way in which natural environments promote human health are sometimes grouped according to two types of ecosystem services: cultural and regulatory. The cultural ecosystem services promote health through such avenues as physical activity, stress relief, and social interaction. The regulatory ecosystem services prevent disease by reducing risk factors, such as air pollution, noise, heat stress, densification, and flooding. This review focuses on the human health benefits of regulatory ecosystem services when applied as nature based solutions (NBS) to address urbanization-induced challenges, especially for children and the elderly.
Twenty-seven articles met the inclusion criteria for this review, which included original research published in peer-review journals since 2010. Additional inclusion criteria included an exploration of the health outcomes of children or the elderly and one or more links to the challenge of urbanization addressed by blue (water) or green spaces as NBS.
Some of the NBS identified in this review include urban trees and other vegetation providing cooling, which reduces the impact of the urban heat island. Vegetation can also improve air quality by removing air pollutants. Open areas in cities (e.g., parks, gardens, playgrounds, etc.) can help prevent flooding through their water regulating functions.
Studies addressing the health outcomes of children focused on birth outcomes, obesity, mental health, behavioral concerns, and allergic sensitization or asthma. One study focused on blood pressure in ten-year-old children. Studies on the elderly focused on mortality, mental health, perceived well-being, respiratory diseases, and cancer. Findings generally support a trend toward positive associations between urban green and blue spaces and health in children and the elderly.
The results, however, are inconclusive due, in part, to the possible influence of socioeconomic factors. How green space is measured is another area of concern, as different studies use different measures and often fail to address such factors as quality, type of amenities, accessibility and actual use. The authors offer suggestions for future research and highlight the need to include social justice issues in such investigations, as people with higher incomes are in a better position than others to counteract some of the urban conditions associated with increased health risks. The authors also call for interdisciplinary efforts to establish consistent and robust evidence of the social, economic, and environmental value of the application of NBS to human well-being for all people while maintaining healthy ecosystems on which we all depend.
The Bottom Line