Estimating multiple greenspace exposure types and their associations with neighbourhood premature mortality: A socioecological study

S.M Labib,Jonny J Huck,Sarah Lindley

doi:10.1016/j.scitotenv.2021.147919

Abstract

BackgroundGreenspace exposures are often measured using single exposure metrics, which can lead to conflicting results. Existing methodologies are limited in their ability to estimate greenspace exposure comprehensively. We demonstrate new methods for estimating single and combined greenspace exposure metrics, representing multiple exposure types that combine impacts at various scales. We also investigate the association between those greenspace exposure types and premature mortality. MethodsWe used geospatial data and spatial analytics to model and map greenspace availability, accessibility and eye-level visibility exposure metrics. These were harmonised and standardised to create a novel composite greenspace exposure index (CGEI). Using these metrics, we investigated associations between greenspace exposures and years of potential life lost (YPLL) for 1673 neighbourhoods applying spatial autoregressive models. We also investigated the variations in these associations in conjunction with levels of socioeconomic deprivation based on the index of multiple deprivations. ResultsOur new CGEI metric provides the opportunity to estimate spatially explicit total greenspace exposure. We found that a 1-unit increase in neighbourhood CGEI was associated with approximately a 10-year reduction in YPLL. Meaning a 0.1 increment or 10% increase in the CGEI is associated with an approximately one year lower premature mortality value. A single 1-unit increase in greenspace availability was associated with a YPLL reduction of 9.8 years, whereas greenness visibility related to a reduction of 6.14 years. We found no significant association between greenspace accessibility and YPLL. Our results further identified divergent trends in the relations between greenspace exposure types (e.g. availability vs. accessibility) and levels of socioeconomic deprivation (e.g. least vs. most). ConclusionOur methods and metrics provide a novel approach to the assessment of multiple greenspace exposure types, and can be linked to the broader exposome framework. Our results showed that a higher composite greenspace exposure is associated with lower premature mortality.

Highlights

The connection between human health and the natural environment is widely recognised (Frumkin et al, 2017; Díaz et al, 2018; Bratman et al, 2019)
In addition to population analysis for all the neighbourhoods (LSOAs) in the study area, we explored whether the association between aggregate greenspace exposure and years of potential life lost (YPLL) varied by subgroups at different levels of deprivation
When we evaluated the associations between greenspace exposure and premature mortality (i.e., YPLL), the results showed that individual greenspace exposure metrics provided considerable variances in effect sizes and directions regarding the associations between exposures and outcomes (Table 1)

Summary

Introduction

The connection between human health and the natural environment is widely recognised (Frumkin et al, 2017; Díaz et al, 2018; Bratman et al, 2019). Several recent reviews have demonstrated that human interactions with nature, exposure to green and blue spaces (commonly referred to jointly as ‘greenspaces’) provide multiple pathways enabling positive health benefits (Hartig et al, 2014; Markevych et al, 2017). The importance of these pathways is recognised in the increasing emphasis on urban green infrastructure as a core part of spatial planning (Lindley et al, 2019; Dennis et al, 2020). Methods: We used geospatial data and spatial analytics to model and map greenspace availability, accessibility and eye-level visibility exposure metrics These were harmonised and standardised to create a novel composite greenspace exposure index (CGEI).

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Conclusion