A review of recent public health literature was conducted to assess the effects of neighborhood greenness on health. In addition to reviewing and summarizing the evidence on exposure to greenness and various health outcomes, this report also presents information about methods used to measure greenness exposure and suggests next steps to advance research in this field.
Neighborhood greenness is generally measured using satellite-based vegetation indices or land-use databases linked to participants' addresses. A less common measure of neighborhood greenness is the distance from a participant's residence to the nearest park, major green space, or public open space. In some – but not many -- studies, participants' perceptions are used as measures of neighborhood greenness.
The literature presents fairly strong evidence of a positive link between exposure to greenness and positive health outcomes. Some of the areas in which greenness seems to offer some health-related protection include cardiovascular disease, mortality, and mental health issues. While exposure to greenness is linked with increased physical activity, the association between greenness and body weight is not as clear. Greenness exposure during pregnancy is also linked with healthier birth weights.
Mental health benefits linked with greater access to green space include reduced risk of stress, psychological distress, prevalence of depression, depressive symptoms, and clinical anxiety in adults. The mental health benefits for children were not as clear, but one study did suggest that access to green space provided some protective benefits related to the well-being of children living in small cities.
This review of the literature also found that certain populations may have lower exposure and decreased access to greenness and green spaces than other populations, yet it's recognized that people with the least access to greenness are the ones who could perhaps benefit the most from greenness exposure. The authors recommend further research and related initiatives in this area as a possible way to lesson socioeconomic health disparities. While the authors recognize the need for further research to firmly establish causal relationships, they note the potential of neighborhood greenness as a promising modifiable factor in promoting health.