Green spaces and health: exploring potential effect modifiers
File(s)
Author(s)
Belcher, Richard
Type
Thesis
Abstract
Noncommunicable diseases place the largest burden on mental and physical health in Europe and can be mitigated by green spaces near people’s residences. However, there are many potentially important, yet understudied, effect modifiers that impact residential green space and health associations. These may change these associations' magnitude, shape and (mostly positive) direction.
In this thesis, I identify and assess four understudied potential effect modifiers of residential green space and health in three epidemiological analyses. I assess effect modification on green space associations with: general health from traffic in analysis 1, mental health from changes in local area socioeconomic deprivation in analysis 2 and mental health from green space naturalness and water in analysis 3. Analyses 1 and 3 are cross sectional, and analysis 3 is longitudinal.
I found that deprivation and water positively affected green spaces’ association with better health. However, the effect of traffic and naturalness depended on the vegetation type and amount of green space present, respectively. A limited evidence base leads me to recommend further study of the impact of wetland, traffic and naturalness as effect modifiers. The latter’s impact on green space and health was inconsistent with the established literature further justifying this recommendation. I suggest a policy of providing green space in socioeconomically deprived areas to benefit public health, supported by my research and a large body of literature.
Given the green spaces physical health benefits alone are approximately a third of the value of the United Kingdom’s Natural Capital, a change in green spaces’ impact on health attributable to effect modifiers, such as I have found, can influence how green spaces are designed and planned. Identifying and quantifying the value of effect modifiers should be a priority for all concerned with maximising the societal benefits we get from existing and new green space.
In this thesis, I identify and assess four understudied potential effect modifiers of residential green space and health in three epidemiological analyses. I assess effect modification on green space associations with: general health from traffic in analysis 1, mental health from changes in local area socioeconomic deprivation in analysis 2 and mental health from green space naturalness and water in analysis 3. Analyses 1 and 3 are cross sectional, and analysis 3 is longitudinal.
I found that deprivation and water positively affected green spaces’ association with better health. However, the effect of traffic and naturalness depended on the vegetation type and amount of green space present, respectively. A limited evidence base leads me to recommend further study of the impact of wetland, traffic and naturalness as effect modifiers. The latter’s impact on green space and health was inconsistent with the established literature further justifying this recommendation. I suggest a policy of providing green space in socioeconomically deprived areas to benefit public health, supported by my research and a large body of literature.
Given the green spaces physical health benefits alone are approximately a third of the value of the United Kingdom’s Natural Capital, a change in green spaces’ impact on health attributable to effect modifiers, such as I have found, can influence how green spaces are designed and planned. Identifying and quantifying the value of effect modifiers should be a priority for all concerned with maximising the societal benefits we get from existing and new green space.
Version
Open Access
Date Issued
2023-11-09
Date Awarded
01/02/2024
License URL
Advisor
Fecht, Daniela
Murray, Kris
Reeves, Jonathan
Sponsor
Natural Environment Research Council (Great Britain)
Medical Research Council (Great Britain)
National Institute for Health Research (Great Britain)
Wildfowl and Wetlands Trust (Trust)
Grant Number
NE/S007415/
MRC/S019669/1, 2019-2024
Publisher Department
School of Public Health
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)