Urban vegetation and heat-related mortality in Seoul, Korea

Abstract

Urban areas are particularly vulnerable to heat-related health outcomes. Simultaneous trends of climate change and urbanization may increase the urban heat-related health burden. We investigated the effects of urban vegetation on heat-related mortality, and evaluated whether different levels of vegetation and individuals' characteristics affect the temperature-mortality associations within Seoul, Korea 2000-2009. We used Normalized Difference Vegetation Index (NDVI) to assess the urban vegetation within Seoul. We applied an overdispersed Poisson generalized linear model with interaction term between temperature and indicator of NDVI group (categorized in 3 levels) to assess the effect modification of the temperature-mortality association by urban vegetation. We conducted stratified analysis to explore whether associations are affected by individual characteristics of sex and age. The association between total mortality and a 1°C increase in temperature above the 90th percentile (25.1°C) (the “heat effect”) was the highest for gus with low NDVI. The heat effect was a 4.1% (95% confidence interval (CI) 2.3, 5.9%), 3.0% (95% CI 0.2, 5.9%), and 2.2% (95% CI -0.5, 5.0%) increase in mortality risk for low, medium, and high NDVI group, respectively. Estimated risks showed similar effects by sex and age. Our findings suggest a higher mortality effect of high temperature in areas with lower vegetation in Seoul, Korea.

A Review of Epidemiologic Studies on Greenness and Health: Updated Literature Through 2017

“…Two studies sought to understand whether the relationship between heat and mortality was modified by greenness exposure and found that the association between temperature and mortality was attenuated in greener areas [54,55]. In Portugal, mortality was 14.7% (95% CI: 1.9, 17.5) higher comparing extremely hot days (> 99 th percentile of temperature) to other days in areas in the lowest greenness quartile (NDVI <0.23), but only 3.0% (95% CI: 2.0, 4.0) higher in areas in the highest NDVI quartile (>0.48) [55].…”

Optimizing the spatial arrangement of trees in residential neighborhoods for better cooling effects: Integrating modeling with in-situ measurements

“…Exposure to elevated surface air temperature can result in a series of consequences on human health that range from mild discomfort to lifethreatening conditions, especially for vulnerable groups such as the elderly, children, and people with heat-related diseases (Son, Lane, Lee, & Bell, 2016;Tan et al, 2010). Previous studies tended to focus on the pedestrian level thermal environment, which is directly related to inhabitants' outdoor thermal comfort (Middel et al, 2014;Skelhorn, Lindley, & Levermore, 2014;Srivanit & Hokao, 2013).…”

Spatial Variation of Urban Thermal Environment and Its Relation to Green Space Patterns: Implication to Sustainable Landscape Planning

“…As an important part of urban green infrastructures, the function of urban green space is also related to the quality of the local environment and the health of the residents [1,2], and plays an important role in urban ecosystems, which can reduce greenhouse gas, regulate the urban microclimate [3], reduce energy consumption [4,5], and maintain ecological security [6,7], which are among a wide range of ecosystem services [8]. The cooling effect of urban green space is regarded as an ecosystem regulating service [9,10].…”