Urban vegetation and heat-related mortality in Seoul, Korea.
Son J-Y, Lane KJ, Lee J-T, Bell ML. Urban vegetation and heat-related
mortality in Seoul, Korea. Environmental Research
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.