Environmental policies to increase urban green space may have sustainable public health benefits
Despite growing evidence of public health benefits from urban green space there has been little longitudinal analysis.
In a new study, Dr. Ian Alcock, Associate Research Fellow, European Center for Environment and Human Health, University of Exeter Medical School and colleagues used panel data to explore three different hypotheses about how moving to greener or less green areas may affect mental health over time.
The sample came from participants in the British Household Panel Survey with mental health data (General Health Questionnaire scores) for five consecutive years, and who relocated to a different residential area between the second and third years.
This current research used over 1,000 individuals to explore the relation between urban green space and well-being (indexed by ratings of life satisfaction) and between urban green space and mental distress (indexed by General Health Questionnaire scores) for the same people over time.
The results showed compared to premove mental health scores, individuals who moved to greener areas (n = 594) had significantly better mental health in all three postmove years (P = .015; P = .016; P = .008), supporting a “shifting baseline” hypothesis.
Individuals who moved to less green areas (n = 470) showed significantly worse mental health in the year preceding the move (P = .031) but returned to baseline in the postmove years.
The authors adjusted their data to remove effects from other factors likely to affect mental health over time such as income, employment and education, as well as factors related to personality.
The researchers write “Moving to greener urban areas was associated with sustained mental health improvements, suggesting that environmental policies to increase urban green space may have sustainable public health benefits.”
Dr. Alcock states in press release "We've shown that individuals who move to greener areas have significant and long-lasting improvements in mental health. These findings are important for urban planners thinking about introducing new green spaces to our towns and cities, suggesting they could provide long term and sustained benefits for local communities."
Dr. Matthew White, Lecturer in Risk and Health and co-author of study commented "We needed to answer important questions about how the effects of green space vary over time. Do people experience a novelty effect, enjoying the new green area after the move, but with the novelty then wearing off? Or do they take time to realize the benefits of their new surroundings as they gradually get to know local parks? What we've found suggests that the mental health benefits of green space are not only immediate, but sustainable over long periods of time."
According to WHO, mental health disorders such as depression are among the 20 leading causes of disability worldwide. Depression affects around 350 million people worldwide and this number is projected to increase.
This study is published in Environmental Science & Technology.