Effect modification of greenness on the association between heat and mortality: A multi-city multi-country study

• Authors: Hayon Michelle Choi, Yale University; Whanhee Lee, Yale University; Dominic Roye, University of Santiago de Compostela; Seulkee Heo, Yale University; Aleš Urban, Czech Academy of Sciences; Alireza Entezari, Hakim Sabzevari Univ; Ana Maria Vicedo-Cabrera, University of Bern; Antonella Zanobetti, Harvard T.H. Chan School of Public Health; Antonio Gasparrini, London School of Hygiene & Tropical Medicine; Antonis Analitis, National and Kapodistrian University of Athens; Aurelio Tobias, Spanish Council for Scientific Research (CSIC); Ben Armstrong, London School of Hygiene & Tropical Medicine; Bertil Forsberg, Umea University; Carmen Íñiguez, University of Valencia; Christofer Astrom, Umea University; Ene Indermitte, University of Tartu; Eric Lavigne, University of Ottawa; Fatemeh Mayvaneh, Hakim Sabzevari University; Fiorella Acquaotta, University of Torino; Francesco Sera, University of Florence; Hans Orru, University of Tartu; Ho Kim, Seoul National University; Jan Kyselý, Czech Academy of Sciences; Joana Madueira, Natl Inst Hlth Dr Ricardo Jorge; Joel Schwartz, Harvard T.H. Chan School of Public Health, Boston; Jouni JK Jaakkola, University of Oulu; Klea Katsouyanni, Natl & Kapodistrian Univ Athens; Magali Hurtado Diaz, National Institute of Public Health; Martina S Ragettli, Swiss Tropical and Public Health Institute, Basel; Mathilde Pascal, Public Health France; Niilo Ryti, University of Oulu; Noah Scovronick, Emory University; Samuel Osorio, University of São Paulo; Shilu Tong, Shanghai Jiao Tong University; Xerxes Seposo, Nagasaki University; Yue Leon Guo, National Taiwan University; Yuming Guo, Monash University; Michelle L Bell, Yale University
• Journal Title: EBIOMEDICINE
• Volume: Volume 84
• Publisher: ELSEVIER | 2022-09-08, Pages 104251-104251
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1016/j.ebiom.2022.104251
• Subjects: Statistics; Health Sciences, Epidemiology; Health Sciences, Medicine and Surgery; Health Sciences, Public Health
• Keywords: Science & Technology; Life Sciences & Biomedicine; Medicine, General & Internal; Medicine, Research & Experimental; General & Internal Medicine; Research & Experimental Medicine; Greenspace; Heat; Mortality; Effect modification; LAND USE/LAND COVER; URBAN GREEN; HEALTH-BENEFITS; VEGETATION; TEMPERATURE; ADAPTATION; CLIMATE; DESIGN; CITIES; SPACE

Abstract

Background: Identifying how greenspace impacts the temperature-mortality relationship in urban environments is crucial, especially given climate change and rapid urbanization. However, the effect modification of greenspace on heat-related mortality has been typically focused on a localized area or single country. This study examined the heat-mortality relationship among different greenspace levels in a global setting. Methods: We collected daily ambient temperature and mortality data for 452 locations in 24 countries and used Enhanced Vegetation Index (EVI) as the greenspace measurement. We used distributed lag non-linear model to estimate the heat-mortality relationship in each city and the estimates were pooled adjusting for city-specific average temperature, city-specific temperature range, city-specific population density, and gross domestic product (GDP). The effect modification of greenspace was evaluated by comparing the heat-related mortality risk for different greenspace groups (low, medium, and high), which were divided into terciles among 452 locations. Findings: Cities with high greenspace value had the lowest heat-mortality relative risk of 1·19 (95% CI: 1·13, 1·25), while the heat-related relative risk was 1·46 (95% CI: 1·31, 1·62) for cities with low greenspace when comparing the 99th temperature and the minimum mortality temperature. A 20% increase of greenspace is associated with a 9·02% (95% CI: 8·88, 9·16) decrease in the heat-related attributable fraction, and if this association is causal (which is not within the scope of this study to assess), such a reduction could save approximately 933 excess deaths per year in 24 countries. Interpretation: Our findings can inform communities on the potential health benefits of greenspaces in the urban environment and mitigation measures regarding the impacts of climate change. Funding: This publication was developed under Assistance Agreement No. RD83587101 awarded by the U.S. Environmental Protection Agency to Yale University. It has not been formally reviewed by EPA. The views expressed in this document are solely those of the authors and do not necessarily reflect those of the Agency. EPA does not endorse any products or commercial services mentioned in this publication. Research reported in this publication was also supported by the National Institute on Minority Health and Health Disparities of the National Institutes of Health under Award Number R01MD012769. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Also, this work has been supported by the National Research Foundation of Korea (2021R1A6A3A03038675), Medical Research Council-UK (MR/V034162/1 and MR/R013349/1), Natural Environment Research Council UK (Grant ID: NE/R009384/1), Academy of Finland (Grant ID: 310372), European Union's Horizon 2020 Project Exhaustion (Grant ID: 820655 and 874990), Czech Science Foundation (22-24920S), Emory University's NIEHS-funded HERCULES Center (Grant ID: P30ES019776), and Grant CEX2018-000794-S funded by MCIN/AEI/ 10.13039/501100011033 The funders had no role in the design, data collection, analysis, interpretation of results, manuscript writing, or decision to publication.