Mechanisms of Impact of Blue Spaces on Human Health: A Systematic Literature Review and Meta-Analysis.

Michail Georgiou,Gordon Morison,Zoë Tieges,Sebastien Chastin,Niamh Smith

doi:10.3390/ijerph18052486

Abstract

Blue spaces have been found to have significant salutogenic effects. However, little is known about the mechanisms and pathways that link blue spaces and health. The purpose of this systematic review and meta-analysis is to summarise the evidence and quantify the effect of blue spaces on four hypothesised mediating pathways: physical activity, restoration, social interaction and environmental factors. Following the PRISMA guidelines, a literature search was conducted using six databases (PubMed, Scopus, PsycInfo, Web of Science, Cochrane Library, EBSCOHOST/CINAHL). Fifty studies were included in our systematic review. The overall quality of the included articles, evaluated with the Qualsyst tool, was judged to be very good, as no mediating pathway had an average article quality lower than 70%. Random-effects meta-analyses were conducted for physical activity, restoration and social interaction. Living closer to blue space was associated with statistically significantly higher physical activity levels (Cohen’s d = 0.122, 95% CI: 0.065, 0.179). Shorter distance to blue space was not associated with restoration (Cohen’s d = 0.123, 95% CI: −0.037, 0.284) or social interaction (Cohen’s d = −0.214, 95% CI: −0.55, 0.122). Larger amounts of blue space within a geographical area were significantly associated with higher physical activity levels (Cohen’s d = 0.144, 95% CI: 0.024, 0.264) and higher levels of restoration (Cohen’s d = 0.339, 95% CI: 0.072, 0.606). Being in more contact with blue space was significantly associated with higher levels of restoration (Cohen’s d = 0.191, 95% CI: 0.084, 0.298). There is also evidence that blue spaces improve environmental factors, but more studies are necessary for meta-analyses to be conducted. Evidence is conflicting on the mediating effects of social interaction and further research is required on this hypothesised pathway. Blue spaces may offer part of a solution to public health concerns faced by growing global urban populations.

Highlights

Introduction2018, increasing the number of people living in urban areas from 751 million in 1950 to
The main reasons for excluding studies were that studies did not measure the right exposure, were qualitative, were conducted in a virtual environment or referred solely to impacts of green space
Our meta-analyses indicated that the blue space benefits on restoration where mainly acquired through a higher amount of blue space within a geographical area (Cohen d = 0.339, 95% CI: 0.072, 0.606), compared to increased contact with blue space (Cohen d = 0.191, 95% CI: 0.084, 0.298)

Summary

Introduction

2018, increasing the number of people living in urban areas from 751 million in 1950 to. 4.2 billion in 2018 [1] This tremendous increase in the urban population has raised several environmental, social and health concerns [2]. Urbanisation is linked to increased risk of non-communicable diseases, premature mortality [3], as well as a higher risk of mental illnesses [4] and social isolation [5]. Urban growth is projected to continue and bring an additional 2.5 billion people to urban areas by 2050 [1]. It is of paramount importance for city-planners to create sustainable and healthy urban environments, which promote mental and physical wellbeing

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Conclusion